Therapeutic drug monitoring
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Large volume
<c 502>
<e 602>
<c 701>
cobas 6000 analyzer series
Mid volume
<c 501>
38 configurations
<c 702> *
7 configurations
<e 601>
cobas 4000 analyzer series
Low volume
<c 311>
•Consistency of interaction with hardware, software and
reagents for less training and more staff flexibility
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concept
<e 411>
* TDM assays in development
3 configurations
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are trademarks of Roche.
©2011 Roche
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
Therapeutic drug monitoring
Precision and method comparison study in routine
laboratories on the COBAS INTEGRA® 800
analyzer and cobas c 501 module
G. Brandhorst1, M. Shipkova2, E. Rosler3, D. Petrova1, M. Orth2, J. Engelmayer1, E. Wieland2, M. Oellerich1
1
Department of Clinical Chemistry, Universitätsmedizin Goettingen, Germany
2
Klinikum Stuttgart, Department of Clinical Chemistry and Laboratory Medicine, Stuttgart, Germany
3
Marienhospital Stuttgart, Stuttgart, Germany
Introduction
Therapeutic drug monitoring (TDM) is a common laboratory
routine used to measure a serum or plasma drug
­concentration for patients using drugs that are typically
­prescribed for long-term intake and which have a narrow
therapeutic range. Within this range most patients will
­experience significant therapeutic effects without an
undesirable degree of adverse reactions. Below the range,
drugs are most likely ineffective. Above the range, there
is a possible toxic side effect without any improvement in
the efficacy of the drug. Consequently, precision at the
relevant medical decision points – the low and high end
of the therapeutic range - is a key performance measure
for this range of tests. TDM has experienced a degree
of technological change over the past years: historically,
HPLC was used for measurement. Today, most tests are
run on automated systems to improve laboratory efficiency.
Key conclusion
The study clearly demonstrates the consistent performance
parity between the COBAS INTEGRA 800 analyzer
and cobas c 501 module and the excellence of the
­intermediate precision of the cobas c 501 module.
For six of the eight assays (including Carbamazepine,
Phenobarbital, Phenytoin, Theophylline, Vancomycin and
Valproic Acid) excellent intermediate precision results
were obtained on both analytical systems.
An evaluation of eight TDM tests was carried out on the
cobas c 501 module and the COBAS INTEGRA® 800
analyzer. The study was carried out across three sites in
Germany.
Evaluator
Laboratory
Country
Hr. Prof. M. Oellerich
Hr. Dr. G. Brandhorst
Fr. J. Engelmayer
Fr. S. Götze
Universitätsmedizin
Göttingen
Germany,
Göttingen
Fr. Dr. M. Shipkova
Fr. K. Rapp
Fr. S. Stier
Katharinenhospital
Stuttgart
Germany,
Stuttgart
Hr. Dr. A. E. Rosler
Marienhospital
Stuttgart
Germany,
Stuttgart
The CVs for both Digoxin and Tobramycin were slightly
higher overall - however, the results were still comparable
between the two analyzers. The method comparison
yielded excellent results for 4 of 8 assays with slopes
less or equal to +/- 4%. The remaining assays showed
a good comparison (1.05 - 1.07). The results showed an
excellent correlation (r) of 0.98 - 1.00.
Study design
The study objectives were 1) to analyze the precision
of immunoassays based on different technologies and
2) to compare the results using routine samples on the
cobas c and COBAS INTEGRA® platforms.
For the study, eight routine TDM tests using different
test principles have been evaluated. (Table 1).
Detailed results & conclusions
Overall, the comparison between the two Roche
systems COBAS INTEGRA 800 analyzer and cobas c
501 module demonstrated very consistent and precise
results and excellent % CV at the relevant medical
decision points.
For intermediate precision, the following detailed
results were obtained:
Carbamazepine: excellent results with CVs between
2.0 and 4.7% were obtained on both
systems.
Digoxin:
comparable results on both analyzers.
CVs up to 8% measured at low
­concentration levels.
Phenobarbital: Very good results with CVs below
5.1% with one exception of 6.3%.
Samples were collected at each site and shared between
the sites. The measurements were done in 2 replicates,
2 runs /day, over 10 days. Intermediate precision was
calculated from 40 replicates. The comparison of the
methods was performed by calculation of the Passing /
Bablok regression analysis. Implausible results were
discussed and repeated if necessary.
Phenytoin:
Theophylline:
Tobramycin:
Vancomycin:
Valproic acid:
excellent results on both analyzers.
excellent results on both analyzers.
Slightly superior results on cobas c
501 module with CVs between 2.4 and
3.0%.
in mid and high concentration, results
superior on cobas c 501 module.
However, at the low level a high CV
was obtained on this analyzer.
excellent and well comparable results
on both analyzers.
very good results below 6%. Slightly
superior results on COBAS INTEGRA
800 analyzer.
Parameter
Expected
range guide
System
Carbamazepine
8 – 12 mg/L
cobas c 501 module
KIMS
0.35 – 20 mg/L
COBAS INTEGRA® 800 analyzer
FPIA
0.12 – 20 mg/L
cobas c 501 module
KIMS
0.3 – 5.0 μg/L
COBAS INTEGRA 800 analyzer
KIMS
0.3 – 5.0 μg/L
cobas c 501 module
KIMS
2.4 – 60 mg/L
COBAS INTEGRA 800 analyzer
FPIA
1.0 – 60 mg/L
cobas c 501 module
KIMS
0.8 – 40 mg/L
COBAS INTEGRA 800 analyzer
FPIA
0.61 – 40 mg/L
cobas c 501 module
KIMS
0.8 – 40 mg/L
Digoxin
0.6 – 1.2 μg/L
Phenobarbital
10 – 30 mg/L
Phenytoin
10 – 20 mg/L
Test principle
Measuring range
package insert
Theophylline
10 – 20 mg/L
COBAS INTEGRA 800 analyzer
FPIA
0.18 – 40 mg/L
Tobramycin
6 – 10 mg/L and
0.5 – 2.0 mg/L
cobas c 501 module
EMIT
0.33 – 10 mg/L
COBAS INTEGRA 800 analyzer
FPIA
0.04 – 10 mg/L
25 – 40 mg/L and
5 – 10 mg/L
cobas c 501 module
EMIT
1.7 – 80 mg/L
COBAS INTEGRA 800 analyzer
FPIA
1.3 – 80 mg/L
50 – 100 mg/L
cobas c 501 module
EMIT
2.8 – 150 mg/L
COBAS INTEGRA 800 analyzer
FPIA
3.15 – 150 mg/L
Vancomycin
Valproic Acid
Table 1: Overview about parameters and test principles
Intermediate precision
For six of the eight assays excellent intermediate precision results were obtained on both analytical systems. The CVs for both
Digoxin and Tobramycin were slightly higher overall - however, the results were still comparable between the two analyzers.
12.0
12.0
10.0
10.012.0
CV [%]
6.0
8.0
10.0
6.0
8.0
4.0
6.0
4.0 4.0
2.0
2.0
0
0
TDM level
1
2
3
cobas c 501
module
TDM level
1
2
3
COBAS INTEGRA 800
analyzer
Fig. 1: Carbamazepine
CV [%]
12.0
8.0
CV [%]
CV [%]
8.0
*Level 3 not measured
10.0
2.0
0
6.0
4.0
2.0
TDM level
TDM level
TDM level
TDM level
1 2 3
1 2 3
1 2 3
1 2 3*
TDM level
TDM
level
®
®
cobas
c2501 COBAS
INTEGRA® 800 Abbott AxSym
1
3
1
2 Abbott
3 Architect
cobas c 501
module
0
COBAS INTEGRA 800
analyzer
Fig. 2: Digoxin
TDM level
TDM level
TDM level
TDM level
1 2 3
1 2 3
1 2 3
1 2 3*
®
®
cobas c 501 COBAS INTEGRA 800 Abbott AxSym Abbott Architect®
analyzer
module
10.0
10.0
8.0
8.0
6.0
4.0
12.0
6.0
4.0
2.0
2.0
0
0
TDM level
1 2 3
Abbott
AxSym®
TDM level
1 2 3*
Abbott
®
*Level
3 not measured
Architect
10.0
8.0
CV [%]
CV [%]
12.0
CV [%]
12.0
6.0
4.0
2.0
TDM level
1
2
3
cobas c 501
module
Fig. 3: Phenobarbital
TDM level
1
2
3
COBAS INTEGRA 800
analyzer
0
TDM
level
TDM
level
TDM
level
TDM level
TDM
level
TDM level
1
1 1 2 23
3
12 2 3 3
1 2 3
1 2 3*
COBAS
INTEGRA
cobas
c 501
cobas
c 501 COBAS INTEGRA® 800
Abbott
AxSym® 800
Abbott Architect®
analyzer
module
Fig. 4: Phenytoin
TDM level
1 2 3
Abbott
AxSym®
TDM level
1 2 3*
Abbott
Architect®
10.0
10.0
8.0
8.0
6.0
4.0
12.0
6.0
4.0
2.0
2.0
0
0
*Level 3 not measure
10.0
8.0
CV [%]
CV [%]
12.0
CV [%]
12.0
6.0
4.0
2.0
TDM level
1
2
3
COBAS INTEGRA 800
analyzer
Fig. 5: Theophylline
Fig. 6: Tobramycin
12.0
10.0
10.0
8.0
8.0
CV [%]
12.0
CV [%]
0
TDMTDM
levellevel
TDM
level
TDM level
TDM level
TDM level
1
2 1 2 33
1 1 22 3 3
1 2 3
1 2 3*
®
®
INTEGRA
cobas
c 501c 501 COBAS INTEGRA COBAS
cobas
800 Abbott
AxSym 800
Abbott Architect
analyzer
module
6.0
4.0
12.0
6.0
4.0
2.0
2.0
0
0
TDM level
1 2 3
Abbott
AxSym®
TDM level
1 2 3*
Abbott
Architect®
*Level 3 no
10.0
8.0
CV [%]
TDM level
1
2
3
cobas c 501
module
6.0
4.0
2.0
TDM level
1
2
3
cobas c 501
module
Fig. 7: Vancomycin
TDM level
1
2
3
COBAS INTEGRA 800
analyzer
0
TDM level TDM level
TDM level
TDM level
TDM level
TDM
1
2
31 2 3
2 1 23 3
1 2 3 1
1 2
®
COBAS
800 ® Abbott Ar
cobas c 501
cobas c 501 COBAS INTEGRA
800INTEGRA
Abbott AxSym
analyzer
module
Fig. 8: Valproic Acid
TDM level
TDM level
TDM level
TDM level
1 2 3
1 2 3
1 2 3
1 2 3*
®
®
cobas c 501 COBAS INTEGRA 800 Abbott AxSym Abbott Architect®
TDM level
TDM level
analyzer
module
1 2 3
Abbott
AxSym®
1 2 3*
Abbott
Architect®
Correlation COBAS INTEGRA 800® analyzer vs. cobas c 501 module
The method comparison yielded excellent results for 4 of 8 assays with slopes less or equal to +/- 4%. The remaining assays
showed a good comparison (1.05 - 1.07). The results showed an excellent correlation (r) of 0.98 - 1.00.
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
0.0
4.0
8.0
12.0
16.0
20.0
Carbamazepine
[mg/L] COBAS INTEGRA 800 analyzer
Fig. 9: Carbamazepine
2.5
2.0
1.5
5.0
1.0
P/B regression
Y = 1.033 *
X – 0.005
md(95) = 0.092
N = 67 r = 0.9920
t = 0.8751
4.5
4.0
3.5
3.0
2.5
20.0
2.0
1.5
18.0
1.0
16.0
0.5
Carbamacepin
[mg/L] cobas c 501 module
Carbamazepine
[mg/L] cobas c 501 module
18.0
AAGP2
Immunoturbidimetry g/L
cobas c 501 module
P/B regression
Y = 1.074 *
X – 0.0314.0
md(95) = 1.453
3.5
N = 77 r = 0.9769
t = 0.9026
3.0
Digoxin
[µg/L] cobas c 501 module
20.0
0.0
14.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
0.5
12.0
Digoxin
0
[µg/L]
COBAS
INTEGRA
800
analyzer
0 0.5 1.0 1.5 2.0 2.5 3.0
10.0
3.5
AAG
Fig. 10: Digoxin
8.0
Immunonephelometry
g/L BN II
6.0
4.0
50.0
40.0
30.0
20.0
10.0
35.0
30.0
25.0
[mg/L] COBAS INTEGRA®
70.0
20.0
15.0
60.0
10.0
5.0
0.0
0.0
P/B regression
Y = 1.014 *
X + 0.074
0.0
md(95) = 1.94
0.0 2.0
4.0 r =
6.00.9868
8.0 10.0 12.0 1
N = 63
t = 0.9171
Carbamacep
2.0
40.0
Phenobarbital
[mg/L] cobas c 501 module
Phenobarbital
[mg/L] cobas c 501 module
60.0
45.0
Phenytoin
[mg/L] cobas c 501 module
P/B regression
Y = 0.982 *
X + 0.18
md(95) = 1.609
N = 58 r = 0.9961
t = 0.9525
70.0
50.0
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0
0.05.0 10.015.0 20.025.030.035.040.045.0
Phenobarbital
[mg/L] COBAS INTEGRA 800 analyzer
Phenytoin
40.0
[mg/L] COBAS INTEGRA 800 analyzer
Fig. 11: Phenobarbital
Fig. 12: Phenytoin
30.0
20.0
10.0
0.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
Phenobarbital
[mg/L] COBAS INTEGRA® 800 analyzer
7
25.0
20.0
15.0
10.0
5.0
0.0
35.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0
P/B regression
Y = 1.069 *
X – 0.041
md(95) = 0.473
N = 47 r = 0.9911
t = 0.9541
30.0
25.0
20.0
15.0
10.0
5.0
0.0
0.06.0
5.07.010.0
15.010.0
20.0 25.0 30.0 35.0
0.0 1.0 2.0 3.0 4.0 5.0
8.0 9.0
Tobramycin
Theophylline
[mg/L] COBAS INTEGRA
analyzer
[mg/L] 800
COBAS
INTEGRA® 800 analyzer
Theophylline
[mg/L] COBAS INTEGRA 800 analyzer
Fig. 13: Theophylline
35.
30.
Theophylline
[mg/L] cobas c 501 module
30.0
10.0
Theophylline
[mg/L] cobas c 501 module
P/B regression
Y = 1.049 *
X – 0.008
md(95) = 0.779
N = 79 r = 0.9966
t = 0.9518
Tobramycin
[mg/L] cobas c 501 module
Theophylline
[mg/L] cobas c 501 module
35.0
25.
20.
15.
10.
Fig. 14: Tobramycin
5.
0.
50.0
40.0
30.0
20.0
10.0
0.0
0.0 10.0 20.0 30.0 40.0 50.0 60.0
Vancomycin
[mg/L] COBAS INTEGRA 800 analyzer
Fig. 15: Vancomycin
120.0
P/B regression
Y = 1.018 *
X – 2.47
md(95) = 3.322
N = 80 r = 0.9911
t = 0.9259
100.0
80.0
60.0
60.0
50.0
40.0
20.0
0.0
Vancomycin
[mg/L] cobas c 501 module
P/B regression
Y = 1.05 *
X + 0.226
md(95) = 1.34
N = 81 r = 0.9952
t = 0.9511
Valproic Acid
[mg/L] cobas c 501 module
Vancomycin
[mg/L] cobas c 501 module
60.0
40.0
0.0 20.0 40.0 60.0 80.0 100.0 120.0
30.0
Valproic
Acid
[mg/L] COBAS INTEGRA 800 analyzer
Fig. 16: Valproic Acid 20.0
10.0
0.0
0.0
10.0
20.0
30.0
40.0
50.0
Vancomycin
[mg/L] COBAS INTEGRA® 800 analyzer
Acknowledgement
A special thank you to all investigators - especially I. Domke and A. Fahle - at the various locations for
performing the study. Thanks also to the Roche colleagues for their dedicated support.
COBAS, COBAS C, COBAS INTEGRA and
LIFE NEEDS ANSWERS are trademarks of Roche.
All other trademarks are property of their respective owners.
©2011 Roche
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
Carbamazepine
ONLINE TDM Carbamazepine, CARB2
Kinetic interaction of microparticles in solution
(KIMS) immunoassay for the quantitative in vitro
determination of carbamazepine in serum and
plasma on cobas c systems*
Indication
Carbamazepine is an anticonvulsant drug used for the treatment of trigeminal neuralgia,1 all forms of partial epilepsy,
generalized tonic-clonic (grand mal) seizures, as well as simple and complex partial seizures.2,3,4 Some dosage forms, e.g.
Equetrol, have been approved for treating bipolar mood disorder.5 The specific mechanism of carbamazepine is proposed as
a depressant action on the transmission through the nucleus ventralis anterior of the thalamus.2,3 In combination with other
clinical information, monitoring carbamazepine levels provides physicians with an effective tool to aid in adjusting dosage
and achieving optimal therapeutic effect while avoiding both sub-therapeutic and toxic drug levels.
Test principle: Kinetic interaction of microparticles in solution (KIMS)
Negative
Bi-drug hapten conjugated
micro-particles
+
Anti-carbamazepine
antibody
Liquid,
R1
ready-to-use,
two-reagent
formulation
eliminates the
need for mixing
R2
Biotinylated
drug
Anticarbamazepine
antibody
+
Streptavidine
coated
latex beads
Aggregation
Aggregation indicates
absence of target
drug in sample
•Biotinylated drug hapten serves as binding
partner to
•anti-carbamazepine antibody
•Streptavidin coated latex beads
•A competitive reaction to a limited amount
of specific anti-carbamazepine antibody
takes place between the hapten and free
carbamazepine in the sample
•A decrease in apparent signal is
­proportionate to the amount of drug present
in the sample
Positive
Bi-drug hapten conjugated
micro-particles
+
Anti-carbamazepine
antibody
+
Drug in sample
No aggregation
Lack of aggregation
indicates presence
of target drug in sample
Negative
Antibody conjugated
Micro-particles
+
Drug-conjugate
* all cobas c systems except cobas c 111 analyzer
Carbamazepine test characteristics
Reaction time
10 min
Test principle
Kinetic interaction of microparticles in solution (KIMS)
Calibration
6-point after reagent lot change, and as required following quality
control procedures
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (sodium or lithium heparin plasma and K2-EDTA plasma)
Sample volume
2 μL
Measuring range
0.35 – 20 μg/mL (1.5 – 85 μmol/L)
Carbamazepine expected values guide
Troupin et al. 6 – when used as sole agent
Shorvon et al. 7
8 – 12 μg/mL (33.8 – 50.8 μmol/L)
4 – 8 μg/mL
(16.9 – 33.8 μmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean μg/mL
2.7
8.2
13.9
μmol/L
11.4
34.7
58.8
CV%
3.5
2.1
1.3
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean μg/mL
2.7
8.2
13.9
μmol/L
11.4
34.7
58.8
CV%
3.4
2.5
2.5
Interferences
Patients with renal insufficiency, such as those on hemodialysis, may exhibit carbamazepine levels in serum or plasma that
are not consistent with clinical expectations for patients with normal renal function. If results are greater than the expected
range, determine if the patient has renal insufficiency.
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
Order information
Online TDM Carbamazepine
100 tests
04490819 190
Preciset TDM I Calibrators
CAL A-F
Diluent
03375790 190
6 x 5 mL
1 x 10 mL
Codes 691-696
TDM Control Set
Level I
Level II
Level III
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
References
1 Blom, S. (1962). Trigeminal neuralgia: its treatment with a new anticonvulsant drug
(G-32883). Lancet: 839-840.
2 Eadie, M.J., Tyler, J.H. (1974). Anticonvulsant Therapy: Pharmacological Basis and Practice.
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
Edinburgh, Great Britain. Churchill Livingstone. Chap. 7.
3 Penry, J.K., Newmark, M.E. (1979). The use of antiepileptic drugs. Ann Int Med. 90: 207-218.
4 Scheuer, M.L., Pedley, T.A. (1990). The evaluation and treatment of seizures. N Engl J Med;
©2011 Roche
322(21): 1468- 1474
5 bipolar disorder
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
6 Troupin, A., Ojemann, L.M., Halpem, L., et al. (1977). Carbamazepine- a double blind comparison with phenytoin. Neurology; 27: 511-519.
7 Shorvon, S.D., Chadwick, D., Galbraith, A.W., et al. (1978). One drug for epilepsy. Br Med J. 1:
474–476.
Digoxin
ONLINE TDM Digoxin, DIG
Kinetic interaction of microparticles in solution
(KIMS) immunoassay for the quantitative in vitro
determination of digoxin in serum and plasma ­
on cobas c systems*
Indication
Digoxin is a digitalis glycoside which is widely used in the treatment of various heart conditions. Digoxin exerts a positive
inotropic effect which increases the contractile response of the myocardial fibers in patients experiencing congestive heart
failure.1 Cardiac glycosides can also produce several electrophysiological effects that produce negative chronotropic effects
on the human heart.2 These effects tend to slow down and regulate a rapid, irregular beat found in patients experiencing
cardiac arrhythmias.3 Due to its extremely narrow therapeutic range, monitoring digoxin concentration provides physicians
with an effective tool to aid in achieving optimal therapeutic effect while avoiding both sub-therapeutic and toxic drug levels.
Test principle: Kinetic interaction of microparticles in solution (KIMS)
Negative
Bi-drug hapten conjugated
micro-particles
+
Anti-carbamazepine
antibody
Liquid,
R1
ready-to-use,
two-reagent
formulation
eliminates the
need for mixing
R2
Aggregation
Aggregation indicates
absence of target
drug in sample
Positive
Bi-drug hapten conjugated
micro-particles
+
Anti-carbamazepine
antibody
+
Drug in sample
No aggregation
Lack of aggregation
indicates presence
of target drug in sample
Negative
Antibody conjugated
Micro-particles
+
Drug-conjugate
•Liquid, ready-to-use, two-reagent formulation
•anti-digoxin monoclonal antibody
•Conjugated digoxin derivative
microparticles
•A competitive reaction to a limited amount
of specific anti-digoxin antibody takes place
•Aggregation indicates absence of target
drug in sample
•Lack of aggregation indicates presence
of drug in sample
•By monitoring the change in scattered light
or absorbance, a concentration dependant
curve is obtained
* all cobas c systems except cobas c 111 analyzer
Digoxin test characteristics
Reaction time
10 min
Test principle
Kinetic interaction of microparticles in solution (KIMS)
Calibration
6-point after reagent lot change, and as required following quality
control procedures
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (Li heparin plasma and K2-EDTA plasma)
Sample volume
5.5 μL
Measuring range
0.3 – 5.0 ng/mL (0.38 – 6.4 nmol/L)
Digoxin Expected Values Guide
Therapeutic effects 4
ESC Guidelines for diagnosis and treatment of acute and chronic heart failure 5
0.8 – 2 ng/mL (1.0 – 2.6 nmol/L)
0.6 – 1.2 ng/mL (0.77 – 1.5 nmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean ng/mL
0.87
1.8
3.0
nmol/L
1.1
2.3
3.8
CV%
4.0
1.6
1.0
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean ng/mL
0.87
1.8
3.0
nmol/L
1.1
2.3
3.8
CV%
6.0
2.4
1.6
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
Order information
Online TDM Digoxin
Preciset TDM I Calibrators
CAL A-F
Diluent
TDM Control Set
Level I
Level II
Level III
250 tests
20737836 322
03375790 190
6 x 5 mL
1 x 10 mL
Codes 691-696
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
References
1 Lee, K.S., Klaus, W. (1971). The subcellular basis for the mechanism of inotropic action of
cardiac glycosides. Pharmacol Rev. 23: 193-261.
2 Hoffman, B.F. (1969). In: Fisch, C., Surawicz, B., eds. Effects of digitalis on electrical activity of
cardiac fibers. Digitalis. New York, NY: Grune and Stratton: 93-109.
3 Moe, G.K., Farah, A.E. (1970). In: Goodman, L.S., Gilman, A. eds. Digitalis and allied cardiac
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
4 Huffman, D.H., Crow, J.W., Pentikaimen, P., Azarnoff, D.L. (1976). Clinical cardiac status, labo-
©2011 Roche
5 Dickstein, K., Cohen-Solal, A., Filippatos, G., McMurray, J.J., Ponikowski, P., Poole-Wilson,
glycosides. The Pharmacologist Basis of Therapeutics. New York, NY. MacMillan Company.
ratory parameters and digoxin usage. Am Heart J. 91: 28.
P.A., et al. (2008). ESC Guidelines for the diagnosis and treatment of acute and chronic heart
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
failure 2008:the Task Force for the Diagnosis and Treatment of Acute and Chronic Heart
Failure 2008 of the European Society of Cardiology. Developed in collaboration with the Heart
Failure Association of the ESC (HFA) and endorsed by the European Society of Intensive Care
Medicine (ESICM). Eur Heart J. 29: 2388-442.
Phenobarbital
ONLINE TDM Phenobarbital, PHNO2
Kinetic interaction of microparticles in solution
(KIMS) immunoassay for the quantitative in vitro
determination of phenobarbital in serum and plasma
on cobas c systems*
Indication
Phenobarbital is one of the most commonly used drugs for the treatment of grand mal, psychomotor epilepsy and other
forms of focal epilepsy. Monitoring the serum level of the drug is essential in order to achieve maximum seizure control while
maintaining minimal blood levels to avoid negative side effects.1,2 As with other anti-convulsant drugs, it is imperative that
each patient’s dosage be individualized.3
Test principle: Kinetic interaction of microparticles in solution (KIMS)
Negative
Antibody conjugated
micro-particles
+
Drug-conjugate
Liquid,
R1
ready-to-use,
two-reagent
formulation
eliminates the
need for mixing
R2
Aggregation
Aggregation indicates
absence of target
drug in sample
Positive
Antibody conjugated
micro-particles
+
Drug-conjugate
+
Drug in sample
•Phenobarbital antibody is covalently coupled
to microparticles and the drug derivative is
linked to a macromolecule
•The kinetic interaction of the microparticles
in solutions is induced by binding of drug
conjugate to the antibody on the
microparticles and is inhibited by the
presence of phenobarbital in the sample
•A competitive reaction to a limited amount
of specific anti-phenobarbital antibody
takes place between the drug conjugate
and free phenobarbital in the sample
•A decrease in apparent signal is
­proportionate to the amount of drug present
in the sample
* all cobas c systems except cobas c 111 analyzer
No aggregation
Lack of aggregation
indicates presence
of target drug in sample
Phenobarbital test characteristics
Reaction time
10 min
Test principle
Kinetic interaction of microparticles in solution (KIMS)
Calibration
6-point after reagent lot change, and as required following quality
control procedures
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (K2 or K3-EDTA , lithium or sodium heparin)
Sample volume
2 μL
Measuring range
2.4 – 60 μg/mL (10.3 – 258.6 μmol/L)
Phenobarbital expected values guide
10 – 30 μg/mL (43.1 – 129 μmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean μg/mL
9.8
24.4
45.1
μmol/L
42.2
105.2
194.4
CV%
5.0
2.4
1.8
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean μg/mL
9.8
24.4
45.1
μmol/L
42.2
105.2
194.4
CV%
5.4
2.4
2.0
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
Order information
Online TDM Phenobarbital
100 tests
200 tests
04490924 190
05027446 190
Preciset TDM I Calibrators
CAL A-F
Diluent
6 x 5 mL
1 x 10 mL
03375790 190
Codes 691-696
TDM Control Set
Level I
Level II
Level III
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
References
1 Johannessen, S.I. (1981). Anti-epileptic drugs: pharmacokinetic and clinical aspects. Ther
©2011 Roche
Drug Monit. 3(1): 17.
2 Koch-Weser, J. (1981). Serum drug concentrations in clinical perspective. Ther Drug Monit.
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
3(1): 3-16
3 Pippenger, C.E. (1980). Effective seizure control requires drug monitoring. Battaglia, B.J., ed.
Clin Chem. New Special Section. Washington, DC: American Association of Clinical Chemistry.
1s and 10s.
Phenytoin
ONLINE TDM Phenytoin, PHNY2
Kinetic interaction of microparticles in solution
(KIMS) immunoassay for the quantitative in vitro
determination of phenytoin in serum and plasma
on cobas c systems*
Indication
Phenytoin has been used extensively for seizure control in patients suffering from grand mal epilepsy, cortical focal seizures
and temporal lobe epilepsy.1 Monitoring the serum level of the drug is essential in order to achieve maximum seizure control
while maintaining minimal blood levels to avoid negative side effects.1,2,3 Due to individual patient variation in absorption and
metabolism, optimum levels may vary.
Test principle: Kinetic interaction of microparticles in solution (KIMS)
Negative
Antibody conjugated
micro-particles
+
Drug-conjugate
Liquid,
R1
ready-to-use,
two-reagent
formulation
eliminates the
need for mixing
R2
Aggregation
Aggregation indicates
absence of target
drug in sample
Positive
Antibody conjugated
micro-particles
+
Drug-conjugate
+
Drug in sample
•Phenytoin is covalently coupled to
microparticles and the drug derivative is
linked to the macromolecule
•The kinetic interaction of microparticles in
solutions is induced by binding of drug­
­conjugate to the anti-body on the
­microparticles and is inhibited by the
­presence of phenytoin in the sample
•A competitive reaction to a limited amount
of specific anti-phenytoin antibody
­t akes place betweenthe drug conjugate
and free phenytoin in the sample
•A decrease in apparent signal is
­proportionate to the amount of drug present
in the sample
* all cobas c systems except cobas c 111 analyzer
No aggregation
Lack of aggregation
indicates presence
of target drug in sample
Phenytoin test characteristics
Reaction time
10 min
Test principle
Kinetic interaction of microparticles in solution (KIMS)
Calibration
6-point after reagent lot change, and as required following quality
control procedures
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (K2 or K3-EDTA , lithium or sodium heparin)
Sample volume
1.7 μL
Measuring range
0.8 – 40 μg/mL (3.2 – 158.4 μmol/L)
Phenobarbital expected values guide4
10 – 20 μg/mL (39.6 – 79.2 μmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean μg/mL
6.8
13.0
22.9
μmol/L
26.9
51.5
90.7
CV%
3.4
2.2
2.5
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean μg/mL
6.8
13.0
22.9
μmol/L
26.9
51.5
90.7
CV%
3.8
3.4
3.6
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
Order information
Online TDM Phenytoin Preciset TDM I Calibrators
CAL A-F
Diluent
TDM Control Set
Level I
Level II
Level III
100 tests
200 tests
04490932 190
05108411 190
03375790 190
6 x 5 mL
1 x 10 mL
Codes 691-696
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
References
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
1 Buchthal, F., Klennox-Buchthal, M.A. (1972). In: Antiepileptic Drugs. Woodbury DM, Penry JK,
Schmidt RP, eds. New York, NY: Raven Press. 93. 209.
2 Buchthal, F, Svensmark, O. (1971). Serum concentration of diphenylhydantoin (phenytoin) and
©2011 Roche
phenobarbital and their relation to therapeutic and toxic effects. Psychiatr Neurol Neurochir.
74: 117-136.
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
3 Booker, H.E., Hosokowa, K., Burdette, R.D., Darcey, B. (1970). A clinical study of serum primidone levels. Epilepsia. 11: 395-402.
4 Booker, H. (1978). In: Pippenger CE; Perry JKC, Jutt H, eds. Anti-epileptic Drugs: Quantitative
Analysis and Interpretation. New York, NY: Raven Press. 253-260.
Theophylline
ONLINE TDM Theophylline, THEO2, THE-2
Kinetic interaction of microparticles in solution
(KIMS) immunoassay for the quantitative in vitro
determination of theophylline in serum and plasma
on cobas c systems*
Indication
Theophylline, a bronchodilator, is widely used to treat patients with asthma, apnea (temporary asphyxia) and other obstructive
lung diseases. Monitoring the serum level of the drug is essential as individual patients can vary in their rate of theophylline
clearance1,2 and severe toxicity has been observed without prior occurrence of minor side effects.3 Several factors can alter
theophylline elimination: it is slowed in obese patients, patients with hepatic disease and those on a high carbohydrate, low protein
diet. Premature infants have very low rates of theophylline elimination.4 Conversely, theophylline elimination in more rapid among
patients who smoke.5 In combination with other clinical data, monitoring serum theophylline levels can provide the physician with
useful information to aid in adjusting a patient’s dosage to achieve optimal therapeutic effect while avoiding drug toxicity.
Test principle: Kinetic interaction of microparticles in solution (KIMS)
Negative
Antibody conjugated
micro-particles
+
Drug-conjugate
Liquid,
R1
ready-to-use,
two-reagent
formulation
eliminates the
need for mixing
R2
Aggregation
Aggregation indicates
absence of target
drug in sample
Positive
Antibody conjugated
micro-particles
+
Drug-conjugate
+
Drug in sample
•Theophylline antibody is covalently coupled
to microparticles and the drug derivative is
linked to a macromolecule
•The kinetic interaction of microparticles in
solution is induced by binding of drug
­conjugate to the antibody on the
­microparticles and is inhibited by the
­presence of theophylline in the sample
•A competitive reaction to a limited amount
of specific anti-theophylline antibody
takes place between the drug conjugate
and free ­theophylline in the sample
•A decrease in apparent signal is
­proportionate to the amount of drug present
in the sample
* all cobas c systems except cobas c 111 analyzer
No aggregation
Lack of aggregation
indicates presence
of target drug in sample
Theophylline test characteristics
Reaction time
10 min
Test principle
Kinetic interaction of microparticles in solution (KIMS)
Calibration
6-point after cobas c pack change, after reagent lot change, and as
required following quality control procedures
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (sodium, ammonium or lithium heparin, K2 or K3-EDTA,
sodium citrate)
Sample volume
2.0 μL
Measuring range6
0.8 – 40 μg/mL (4.4 – 222 μmol/L)
Phenobarbital expected values guide4
10 – 20 μg/mL (55.5 – 111 μmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean μg/mL
4.3
14.3
34.1
μmol/L
23.9
79.4
189.3
CV%
1.7
1.3
1.2
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean μg/mL
4.3
14.3
34.1
μmol/L
23.9
79.4
189.3
CV%
2.8
1.7
1.9
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
Order information
Online TDM Theophylline
Preciset TDM I Calibrators
CAL A-F
Diluent
TDM Control Set
Level I
Level II
Level III
100 tests
04491025 190
03375790 190
6 x 5 mL
1 x 10 mL
Codes 691-696
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
References
1 Piafsky, K.M., Ogilvie, R.I. (1975). Drug therapy. Dosage of theophylline in bronchial asthma. N Engl
J Med. 292: 1218-1222.
2 Leung, P., Kalisker, A., Bell, T.D. (1977). Variation in theophylline clearance rate with time in chronic
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
3 Zwillich, C.W., Sutton, F.D., Neff, T.A., et al. (1975). Theophylline-induced seizures in adults.
©2011 Roche
4 Ogilvie, R.I. (1978). Clinical pharmacokinetics of theophylline. Clinical Pharmacokinetics. 3: 267-293.
childhood asthma. J Allergy Clin Immun. 59: 440-444.
Correlation with serum concentrations. Ann Intern Med. 82: 784-787.
5 Hendeles, L., Weinberger, M.M. (1981). Theophylline therapeutic use and serum concentration
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
monitoring. In: Taylor WJ, Finn AL, eds. Individualizing Drug Therapy: Practical Applications of
Drug Monitoring, I. New York, NY: Gross Townsend Frank, Inc. 31-66.
6 Jackson, F.R., Garrido, R., Silverman, H.I., Salem, H. (1973). Blood levels following oral administration
of theophylline preparations. Ann Allergy. 31: 413-419.
Tobramycin
ONLINE TDM Tobramycin, TOBR2
Kinetic interaction of microparticles in solution
(EMIT) immunoassay for the quantitative in vitro
determination of tobramycin in serum and plasma
on cobas c systems*
Indication
Tobramycin is an aminoglycoside antibiotic used in the treatment of infections caused by Pseudomonas aeruginosa, Proteus species,
E.coli, Klebsiella, Serratia, Citrobacter, Staphylococcus aureus, Enterobacter and other microorganisms. The half-life of tobramycin
in serum or plasma correlates closely with renal function and thus is quite variable between individuals over time.1,2 Serum or plasma
tobramycin concentration is also impacted by mode of administration, the volume of extracellular fluid, the duration of the treatment
and physiological changes during the illness and therapy. A peak therapeutic range is suggested for antimicrobial effectiveness.
However, patients with pre-existing renal damage, or those to whom tobramycin has been administered for prolonged periods, may
develop hearing impairment and/or nephrotoxicity.3 Elevated or increasing trough levels are an indication of drug accumulation due
to renal impairment. Therefore, the monitoring of tobramycin at peak and trough concentrations is critical in the prevention of
these serious complications.4
Test principle: Homogeneous enzyme immunoassay technique (EMIT)
No drug in the sample
Anti-drug
antibody
Drug labeled enzyme:
Enzyme = Glucose-6phosphate
dehydrogenase
+
+
Drug in the sample
Substrate =
Glucose-6phosphate
Nicotinamide
adenin
dinucleotide
+ NAD
The enzyme is only active
if not bound to antibody.
Drug sample
NADH absorbs at 340 nm
Reaction direction: increase
+
+ NAD
Drug labeled enzyme
is bound to
anti-drug-antibody
Enzyme inactive
+
+
+ NAD
+
+ NAD
In a competition, the free drug competes with drug-enzyme-conjugate for the antibody
More drug in the sample more antibody–binding-sites are blocked by drug
• less drug-enzyme-conjugates are bound to antibody
• more NADH is built
•The assay is based on competition between drug in the sample and drug labeled with the enzyme glucose-6-phosphate
dehydrogenase (G6PDH) for antibody binding sites
•Enyzme activity decreases upon binding to the antibody, so the drug concentration in the sample can be measured in terms
of enzyme activity
•Active enzyme converts oxidized NAD to NADH, resulting in an absorbance change that is measured spectrophotometrically
* all cobas c systems except cobas c 111 analyzer
Tobramycin test characteristics
Reaction time
10 min
Test principle
Homogeneous enzyme immunoassay technique (EMIT)
Calibration
6-point after cobas c pack change, after reagent lot change, and as
required following quality control procedures.
Calibration on cobas c includes a recalibration every 3 days.
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (K2 or K3-EDTA, sodium citrate, fluoride oxalate, sodium
or lithium heparin)
Sample volume
2.4 μL
Measuring range
0.33 – 10 μg/mL (0.71 – 21.4 μmol/L)
Tobramycin expected values guide4
Peak
Trough
6 – 10 μg/mL (12.8-21.4 μmol/L)
0.5 – 2.0 μg/mL (1.1-4.3 μmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean μg/mL
1.6
3.6
7.7
μmol/L
3.4
7.7
16.5
CV%
4.2
2.8
2.9
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean μg/mL
1.6
3.6
7.7
μmol/L
3.4
7.7
16.5
CV%
4.5
3.1
2.8
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
Order information
Online TDM Tobramycin
Preciset TDM I Calibrators
CAL A-F
Diluent
100 tests
04491033 190
03375790 190
6 x 5 mL
1 x 10 mL
Codes 691-696
TDM Control Set
Level I
Level II
Level III
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
Multiclean
59 mL
04708725 190
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
References
©2011 Roche
2 Naber, K.G., Westinfelder, S.R., Madsen, P.O. (1973). Pharmacokinetics of the aminoglycoside
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
3 Sande, M.A., Mandell, G.L. (1980). Antimicrobial Agents, the aminoglycosides. In: Gilman, A.G.,
1 Cipoll, R.J., Seifert, R.D., Zaske, D.E., et al. (1980). Systematically individualizing tobramycin
dosage regimens. J Clin Pharm. 20: 570-580.
antibiotic tobramycin in humans. Antimicrob Agents Chemother. 3: 469-473.
Goodman, L.S., Gilman, A., eds. The Pharmacological Basis of Therapeutics. New York, NY:
MacMillan. 1162-1180.
4 Baselt, R.C., Cravey, R.H. (1990). Disposition of Toxic drugs and Chemicals in Man. 3rd ed. 805-807.
Valproic Acid
ONLINE TDM Valproic Acid, VALP2
Kinetic interaction of microparticles in solution
(EMIT) immunoassay for the quantitative in vitro
determination of valproic acid in serum and plasma
on cobas c systems*
Indication
Valproic acid (VPA) is an anticonvulsant medication which is used mainly for the treatment of primary and secondary­generalized
seizures, but is also effective against absence seizures.1,2 It is particularly effective in myoclonus and is the drug of choice in
photosensitive epilepsy.2 Although VPA is used in conjunction with other anti-epileptic medications, more recent studies have
shown benefits of converting treatment to VPA monotherapy.3 Also, a growing body of evidence suggests that VPA is useful
in the treatment of affective disorders, in particular lithium-insensitive bipolar disorders.4 Valproic acid has the fewest adverse
side effects of all the widely-used anti-epileptic agents. Some incidences of tremor, coma or stupor have been noted – often in
­conjunction with other co-administration of other anti-epileptic drugs. Pharmacokinetics of VPA are highly variable depending on
the form of drug and route of administration, as well as individual variations in metabolism and clearance.5 Therefore, monitoring
VPA concentrations during therapy is essential in order to provide the physician with an indicator for adjusting dosage.
Test principle: Homogeneous enzyme immunoassay technique (EMIT)
No drug in the sample
Anti-drug
antibody
Drug labeled enzyme:
Enzyme = Glucose-6phosphate
dehydrogenase
+
+
Drug in the sample
Substrate =
Glucose-6phosphate
Nicotinamide
adenin
dinucleotide
+ NAD
The enzyme is only active
if not bound to antibody.
Drug sample
NADH absorbs at 340 nm
Reaction direction: increase
+
+ NAD
Drug labeled enzyme
is bound to
anti-drug-antibody
Enzyme inactive
+
+
+ NAD
+
+ NAD
In a competition, the free drug competes with drug-enzyme-conjugate for the antibody
More drug in the sample more antibody–binding-sites are blocked by drug
• less drug-enzyme-conjugates are bound to antibody
• more NADH is built
•The assay is based on competition between drug in the sample and drug labeled with the enzyme glucose-6-phosphate
dehydrogenase (G6PDH) for antibody binding sites
•Enyzme activity decreases upon binding to the antibody, so the drug concentration in the sample can be measured in terms
of enzyme activity
•Active enzyme converts oxidized NAD to NADH, resulting in an absorbance change that is measured spectrophotometrically
* all cobas c systems except cobas c 111 analyzer
Valproic Acid test characteristics
Reaction time
10 min
Test principle
Homogeneous enzyme immunoassay technique (EMIT)
Calibration
6-point after cobas c pack change, after reagent lot change, and as
required following quality control procedures.
Calibration on cobas c includes a recalibration every 3 days.
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (K2 or K3-EDTA, sodium or lithium heparin)
Sample volume
2.0 μL
Measuring range
2.8 – 150 μg/mL (19.4 – 1040 μmol/L)
Valproic Acid expected values guide 2
50 - 100 μg/mL (346.5 - 693.0 μmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean μg/mL
37.9
80.5
117.4
μmol/L
262.6
557.9
813.6
CV%
3.0
2.1
2.6
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean μg/mL
37.9
80.5
117.4
μmol/L
262.6
557.9
813.6
CV%
4.4
3.3
4.2
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
Order information
Online TDM Valproic Acid
Preciset TDM I Calibrators
CAL A-F
Diluent
TDM Control Set
Level I
Level II
Level III
100 tests
200 tests
04491041 190
05108438 190
03375790 190
6 x 5 mL
1 x 10 mL
Codes 691-696
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
References
1 Chadwick, D. (1988). Comparison of monotherapy with valproate and other antiepilepticdrugs
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
2 Wallace, S.J. (1986). Use of ethosuximide and valproate in the treatment of epilepsy. Neurol
©2011 Roche
3 Wilder, B.J., Rangel, R.J. (1988). Review of valproate monotherapy in the treatment of gener-
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
4 Post, R.M. (1989). Emerging perspectives on valproate in affective disorders. J Clin Psychiatry.
in the treatment of seizure disorders. AM J Med. 84 (suppl 1A): 3-6
Clin. 4: 601-616.
alized tonic-clonic seizures. Am J Med. 84 (suppl 1A): 7 -13.
50: 23-29.
5 Zaccara, G., Messori, A., Moroni, F. (1989). Clinical pharmacokinetics of valproic acid. Clin
Pharmacokinet. 17: 327-344.
Vancomycin
ONLINE TDM Vancomycin, VANC2
Kinetic interaction of microparticles in solution
(EMIT) immunoassay for the quantitative in vitro
determination of vancomycin in serum and plasma
on cobas c systems*
Indication
Vancomycin is a complex glycopeptide antibiotic, which has been used to treat penicillinase-producing staphylococci.1 It is the
treatment of choice for antibiotic resistant Staphylococcus aureus,2,3 as well as for the treatment of gram-positive infections
where allergies to penicillin or cephalosporin play a role. Vancomycin is also used in the treatment of antibiotic-induced
enterocolitis associated with Clostridium difficile and streptococcal or enterococcal endocarditis, the latter in conjunction
with an aminoglycoside, when penicillin or ampicillin is not an option.4 Monitoring the peak and trough serum or plasma
levels is essential to optimize therapy and avoid potentially serious side effects including ototoxicity, nephrotoxicity, phlebitis
and reversible neutropenia.5
Test principle: Homogeneous enzyme immunoassay technique (EMIT)
No drug in the sample
Anti-drug
antibody
Drug labeled enzyme:
Enzyme = Glucose-6phosphate
dehydrogenase
+
+
Drug in the sample
Substrate =
Glucose-6phosphate
Nicotinamide
adenin
dinucleotide
+ NAD
The enzyme is only active
if not bound to antibody.
Drug sample
NADH absorbs at 340 nm
Reaction direction: increase
+
+ NAD
Drug labeled enzyme
is bound to
anti-drug-antibody
Enzyme inactive
+
+
+ NAD
+
+ NAD
In a competition, the free drug competes with drug-enzyme-conjugate for the antibody
More drug in the sample more antibody–binding-sites are blocked by drug
• less drug-enzyme-conjugates are bound to antibody
• more NADH is built
•The assay is based on competition between drug in the sample and drug labeled with the enzyme glucose-6-phosphate
dehydrogenase (G6PDH) for antibody binding sites
•Enyzme activity decreases upon binding to the antibody, so the drug concentration in the sample can be measured in terms
of enzyme activity
•Active enzyme converts oxidized NAD to NADH, resulting in an absorbance change that is measured spectrophotometrically
* all cobas c systems except cobas c 111 analyzer
Vancomycin test characteristics
Reaction time
10 min
Test principle
Homogeneous enzyme immunoassay technique (EMIT)
Calibration
6-point after cobas c pack change, after reagent lot change, and as
required following quality control procedures.
Calibration on cobas c includes a recalibration every 3 days.
Traceability
Standardized against USP reference standards
Sample material
Serum, Plasma (K2 or K3-EDTA, sodium citrate, fluoride oxalate)
Sample volume
2.0 μL
Measuring range
1.7 – 80 μg/mL (1.2 – 55.2 μmol/L)
Vancomycin expected values guide 4
Peak
Trough
25 - 40 μg/L
5 - 10 μg/L (17.3 - 27.6 μmol/L)
(3.5 - 6.9 μmol/L)
Repeatability (Within-run precision)
Control 1
Control 2
Control 3
Mean μg/mL
6.8
21.5
40.9
μmol/L
4.7
14.8
28.2
CV%
1.8
1.7
2.6
Intermediate precision
(total precision/between-run precision/between-day precision)
Control 1
Control 2
Control 3
Mean μg/mL
6.8
21.5
40.9
μmol/L
4.7
14.8
28.2
CV%
3.5
2.4
3.1
Key ONLINE TDM points
•high specificity to parent drug
•negligible cross-reactivity to a broad spectrum of compounds
•no significant interference to 16 common drugs
•no HAMA cross-reactivity
Order information
Online TDM Vancomycin Preciset TDM I Calibrators
CAL A-F
Diluent
TDM Control Set
Level I
Level II
Level III
100 tests
200 tests
04491050 190
05108420 190
03375790 190
6 x 5 mL
1 x 10 mL
Codes 691-696
2 x 5 mL
2 x 5 mL
2 x 5 mL
04521536 190
Code 310
Code 311
Code 312
References
COBAS, COBAS C and LIFE NEEDS ANSWERS
are trademarks of Roche.
1 McCormick, M.H., Stark, W.M., Pittinger, R.C., McGuire, J.M. (1956). In:antibiotics Annual.
New York, NY: Medical Encyclopedia. 606-611.
2 Crossley, K.B., Landesman, B., Zaske, D. (1979). An outbreak of infections caused by strains of
©2011 Roche
Staphylococcus aureus resistant to methicillin and aminoglycosides. J Infect Dis. 139: 273-279.
3 Sorrell, T.C., Packham, S., Shanker, M., Foldes, M., Munro, R. (1982). Vancomycin therapy for
Roche Diagnostics Ltd.
CH-6343 Rotkreuz
Switzerland
www.cobas.com
methicillin-resistant Staphylococcus aureus. Ann Intern Med. 97: 344-350.
4 Cook, F.V. (1978). Vancomycin revisited. Ann Intern Med. 88: 813-818.
5 Zaccara, G., Messori, A., Moroni, F. (1989). Clinical pharmacokinetics of valproic acid. Clin
Pharmacokinet. 17: 327-344.