DRUG PRESCRIBING
PATTERN IN
OBSTETRICS
A CASE STUDY OF UNIVERSITY OF BENIN
TEACHING HOSPITAL (UBTH), NIGERIA
BY
DR TAIWO FILUSI, DR PATRICK ERAH AND
DR ADEDAPO ANDE
AUTHORS
DR TAIWO EMMANUEL FILUSI; B.PHARM, PHARM D
PHARMACIST COUNCIL OF NIGERIA, LAGOS
DR PATRICK ERAH;
B.PHARM, M PHARM, PHD
DEPT OF CLINCAL PHARMACY AND PHARMACY
PRACTICE, UNIVERSITY OF BENIN, NIGERIA
DR ADEDAPO ANDE;
BSc, MB:ChB, FWACS,
FICS,MPH
CONSULTANT OBSTETRICIAN AND GYNAECOLOGIST
UBTH, NIGERIA
DEFINITIONS
• Obstetrics- The science that deals with
management of pregnancy from prenatal,
parturition, to pueperal stages.
• Prenatal- Between the last menstrual period and
delivery (usually 40 weeks)
• Parturition- Labour or act of delivery
• Pueperium- The period immediately following
delivery till involution. (usually 6-8 weeks)
The Thalidomide Tragedy
• Thalidomide – A wonder drug that turned to a
wasteful dragon
………………
Summary of Other Sordid tales
• Margaret from USA took Isotretinoin (Acutane)
for 6 weeks for treatment of acne but had a
premature deliver at 34 weeks of a baby with
water in brain and heart deformities
• Deborah in the UK was given Ritodrine
(Yutopar) to inhibit premature labour. She died
as a result of adverse drug reactions due to an
error in mixing the drug with saline solution
instead of dextrose solution.
REMEMBER
• Drugs can have harmful effects at anytime during
pregnancy
• 1st trimester- drugs cause congenital malformations
(teratogenesis)
• 2nd & third trimesters- growth and functional
development and fetal tissues are affected
• Before term/Labour –Labour complications and effect
on the neonate.
• However, irrational fear of using drugs during
pregnancy can also result in harm
RULES FOR PRESCRIBING IN
PREGNANCY
...........
– If possible, review patients and counsel them before
planning a pregnancy
– Question the real need for any drug in pregnancy
giving due consideration to alternative methods of
treatment
– Review all drug regimens carefully to minimize risks
– Use medicines that have been widely employed in
pregnancy for years in preference to the latest drugs
CONDITIONS WHEN DRUGS
MIGHT BE USED IN
PREGNANCY
………
– Infertility, when drugs may be used to stimulate ovulation
– Acute conditions that arise during pregnancy (pain, fever,
infections, coughs and colds) or chronic conditions unrelated
to pregnancy (Asthma, Epilepsy, Diabetics).
– Conditions commonly related to pregnancy (morning
sickness, hypertension, anaemia)
– Complications of pregnancy and labour (threatened
abortion, premature labour, toxaemia, pain in childbirth.
TERATOGENIC DRUGS
Few essential drugs conclusively proven to be
teratogenic in human include:
– Alkylating agents, e.g Cyclophosphamide, Chlormethidine,
– Antimetabolite agents e.g. Cytarabine, Fluorouracil,
Mercaptopurine, Methotrexate etc.
– Carbamazepine
– Common anticoagulants e.g Warfarin
– Lithium
– Penicillamine
– Phenytoin
– Valproic acid
SAFETY OF ANTIBIOTICS
DURING PREGNANCY
• All drugs, including antibiotics should be
avoided during pregnancy, however when
necessary, the following guideline can be
used
SAFETY OF ANTIBIOTICS
DURING PREGNANCY
Antibiotic
Penicillins
Trimester in
Comments
which
antibiotic is
considered safe
All
Studies of combination with
clavulanic have not demonstrated
toxic effects
Quinolones None
Diseases of the joints have been
noted when used in immature
animals, nalidxic acid has been used
safely in second and third trimesters
but should be discontinued at labour
SAFETY OF ANTIBIOTICS DURING
PREGNANCY CONTD
Sulphonamides
Second
Tetracycline
None
Possible antifolate effects in
first trimester, risk of brain
damage caused by bile
pigment(bilirubin) in third
trimester.
Material risk of liver, pancreas,
or kidney diseases; fetal risk of
teeth discoloration, abnormal
development of of bone
tissues and retarded bone
growth
Trimethoprim
First & third
Folate antagonism
WHO Core Prescribing Indicators
•
•
•
•
•
The WHO Core indicators provide an objective
evaluation of drug use situation in a country, region or
individual health facility. They include:Average no of drugs per encounter
% of drugs prescribed by generic name
% of encounters with an antibiotic prescribed
% of encounter with an injection prescribed
% of drugs prescribed from the essential drug list or
formulary.
Aims and objectives
Main Objective:To investigate drug prescribing pattern by
obstetricians in UBTH
Specific Objectives
1. To assess rational prescribing by obstetricians in
UBTH using WHO core prescribing indicators
2. To determine the most frequently prescribed drugs in
prenatal, parturition, and puerperium
3. To determine the most commonly prescribed classes
of drugs in prenatal, perinatal, and puerperium
Aims and objectives……
4. To determine the most commonly prescribed
antibiotics
5. To determine the most frequently diagnosed
illness.
6. To determine the most commonly prescribed
drug for the most frequently diagnosed illness
Methodology
Study Location
Obstetrics and gynaecology department, UBTH.
UBTH is 550 bed, tertiary health care facility, having all
the basic areas of medical specialty. It also serves as a
teaching hospital for medicine, pharmacy, nursing, and
medical laboratory students.
• Sample Selection: Case notes of patients from
each of the ten consulting units in Jan.–Dec. 2003
were randomly selected and reviewed retrospectively
for drug use from antenatal booking through labour
and delivery to six weeks post partum.
• Sample Size: 473 encounters and 839
prescriptions
Procedure
1.
2.
3.
4.
5.
6.
Consent to undertake the study was obtained
Familiarization with the department, operations and
staff
Discussion and consultation with relevant staff
Casenotes retrospectively reviewed through prenatal,
perinatal and postnatal care
Data recorded in a customised data sheet
Consultants were asked questions arising from casenote review
Data management and analysis
Evaluation was done using:
1.WHO core prescribing indicators
2. Other parameters
3.Microsoft excel
4. Manual calculations
Results.. Subspecialty division and
consultant distribution
S/N
Unit
No. of Consultant
1
Fertility regulation (family planning)
3
2
Infertility, human reproduction and
Endocrinology
1
3
Faeto-maternal unit
3
4
Urogynaecology
3
Results... Prescribers Distribution in
the ten consulting units
Consulting unit
1
2
3
4
5
6
7
8
9
10
Consultant
1
1
1
1
1
1
1
1
1
1
Senior Registrar
1
1
1
0
1
1
1
0
1
1
Registrar
1
2
1
1
1
2
1
1
1
1
Senior House
Officer(medical
officer)
1
1
1
1
1
1
1
1
1
1
House
Officer
2
2
2
2
2
2
2
2
2
2
Doctor’s Cadre
Results…..Pharmacists staffing and
cadre at O &G Pharmacy
Cadre
No
Senior Pharmacist
1
Intern Pharmacist
1
Others
Nil
Results…Age distribution of
booking (Prenatal) patients
Mean  Std.
Deviation
Age range
28.5 2.12
<16
16-20
No
0
5
%
0
2.9
21-25
26-30
31-35
42
56
48
24.7
32.9
28.2
36-40
41-45
15
3
1
8.8
1.8
0.6
46
Results…Conformity of prescribers
to WHO prescribing indicators
Prescribing indicators
Prenatal
Perinatal
Puerperium
Standard
1
Average number of
drugs per
encounter
2.5
1.6
2.6
1.6 – 1.8
2
Percentage drugs
prescribed by
generic name
30.8%
37.1%
49.6%
100%
3
Percentage encounters 5.9%
with an antibiotic
prescribed
11.5%
32%
20.0 26.8%
4
Percentage encounters 5.2%
with an injection
prescribed
90.4%
14.4%
13.4 –
24.1%
5
Percentage of drugs
prescribed from
essential drug list
97.6%
99.6%
100%
99.7%
Summary of most frequently prescribed drugs
and diagnosed illness
Criterium
Prenatal
Perinatal
Most
frequently
prescribed
drugs
Routine
Haematinics(
Ferrous
sulphate,Folic
acid,Pyrimethamine)
(58% )
Haematinics(
66% )
Antimalarials(
13%)
Oxytocin inj. (15%) Paracetamol (14%
)
Pentacozin
(Sosegon) inj.(9% ) Metronidazole
(13% )
Classes of
most
frequently
prescribed
drugs
Oxytocics (35% )
Analgesics (32% )
Puerperium
Haematincs
(31% )
Antibiotics
(46% )
Summary of most frequently prescribed drugs
and diagnosed illness
Most frequently
prescribed antibiotics
Metronidazole(37% )
Augmentin(33% )
Most frequently
diagnosed illness
Malaria (45% )
Anaemia (40% )
Most frequently
prescribed drugs for
most frequently
diagnosed illness
Chloroquine(58% )
Quinine (26% )
Four Most Frequently Prescribed
drugs in Prenatal care
140
127
Number of time Prscribed
120
100
80
60
40
25
24
17
20
0
Routine
Haematinics
(RH)
Vitamin C
Paracetamol
Chloroquine
(Tablets)
Routine Haematinics includes Ferrous Sulphate tablets, folic acid
tablets and pyremethamine (Daraprim) tablets.
Total number of prescriptions - 218
Results…. Five most frequently
prescribed drugs in perinatal
30
No. of time prescribed
25
Total number of prescriptions - 218
20
15
Series1
10
5
0
Oxytocin inj Sosegon inj Vitamin K inj Paracetamol Ergotamine
tablets
inj
Results…. Six most frequently
prescribed drugs in puerperium
No. of time prescribed
40
35
30
25
20
15
10
5
0
Results…… Five most frequently
prescribed classes of drugs in
prenatal
13%
3%
Haematinics
Analgesics
Antibiotics
Antimalarial
8%
10%
66%
Antihistamine
Results… Four most frequently
prescribed classes of drugs in parturition
18%
35%
Oxytocics
Analgesics
Antibiotics
Haemetinics
15%
32%
Results... Five most commonly
prescribed classes of Drugs in
Puerperium
4%
3%
16%
46%
Haemetinics
Antibiotics
Analgesics
Antimalarial
Chymotrypsin
31%
Results… Three most commonly
prescribed classes of drugs in prenatal,
Parturition, Puerperium
21%
19%
60%
Haematinics
Analgesics
Antibiotics
Results…Seven most commonly
prescribed antibiotics in Prenatal,
Parturition and Puerperium
50
45
43
38
35
30
25
20
15
13
10
6
5
5
5
5
ro
m
ax
Zi
th
in
om
yc
ry
th
r
E
A
m
pi
cl
ox
at
Zi
nn
m
yc
in
ta
G
en
id
a
ro
n
M
et
ug
m
en
zo
le
tin
0
A
No. of Time Prescribed
40
Results…Three most frequently
diagnosed illness (in Prenatal)
30
25
20
No. of
15
diagnosis
26
23
10
9
5
0
Malaria
Anaemia
UTI
Results…Frequency of Antimalarial
Prescription
35
Frequency of Antimalarial Prescription
30
29
35
25
20
15
30
29
25
20
13
15
13
10
10
5
5
1
1
0
3
3
4
4
0
Chloroquine
Quinine
Chloroquine
Quinine
Paluther
Paluther
Daraprim
Daraprim
Fansidar Fansidar
RECOMMENDATIONS
• Pharmacists like Medical Doctors, need more
concentration or specialization in basic clinical
areas to enhance their professional relevance in
medical practice.
• WHO should conduct studies in Obstetrics to
establish standard core prescribing indicators,
because the currently available standard are not
applicable to Obstetrics
• Use of Daraprim (Pyrimethamine) as routine
drug in first trimester should be reconsidered
since Pyrimethamine (Daraprim) is a folate
antagonist and in fact theoretically teratogenic.
RECOMMENDATIONS …..
• The obstetricians need more awareness on the
necessity of prescribing in generics as advocated
by WHO.
• There is need to repeat this study using another
facility to compare and contrast the results.
• It is pertinent to note that ACT use is now
incorporated in the Malaria Treatment Policy for
management of malaria in pregnant women in
Nigeria. There is need for caution in order to
avoid another “Thalidomide tragedy”.
CONCLUSION
• The WHO prescribing indicators are useful partly but
not absolutely in analyzing rational prescribing in
obstetrics.
• UBTH Obstetricians conform to applicable indicators
except prescription in generics which fell below
standard.
• Malaria and Anaemia were the most commonly
diagnosed illness in pregnancy.
• Overall, prescriptions compare favourably with
documented standard and drugs that commonly pose
risk to faeto-maternal well being are not used in UBTH.
REFERENCES
• Chetley A., problem drugs, ‘Drugs in Pregnancy’
Amsterdam health action International, 1992, p.
125 – 135.
• How to investigate drug use in health facilities –
selected drug use indicators, WHO, Geneva,
1993, (WHO/DAP/93.1).
• WHO, Geneva, 1993, (WHO/DAP/93.1).
• WHO Model Formulary, WHO, U.K, 2002. P.
477.478.
Thank you for your attention