Pharmacotherapy of antifungal drugs Isabel Spriet Pharmacy Dpt, UZ Leuven The fungal ‘players’ Opportunistic fungi – Normal flora Candida spp. – Ubiquitious in our environment Aspergillus spp. Cryptococcus spp. Mucor spp. Newly emerging fungi - Fusarium - Scedosporium Endemic geographically restricted - Blastomyces spp. - Coccidiodes spp. - Histoplasma spp. Invasive fungal infections Incidence Solid organ transplant: 5-42% Bone marrow transplant: 15-25% ICU: 17% Singh N. Clin Infect Dis 2000;31:545-53 Vincent JL. Intens Care Med 1998; 24:206-216 Candidemia – Mortality rate Pathogen % Isolated % Mortality CNS 31.9 21 S aureus 15.7 25 Enterococci 11.1 32 Candida spp. 7.6 38 E. Coli 5.7 24 Klebsiella spp. 5.4 27 Enterobacter spp. 4.5 28 Pseudomonas spp. 4.4 33 Serratia spp. 1.4 26 S. viridans 1.4 23 Hospital acquired pathogens and their associated mortality Edmond et al. CID 1999; 29:239-44. Invasive Aspergillosis – Mortality Rate Review of 1941 Patients from 50 Studies Case Fatality Rate (%) 100 80 60 40 20 0 Overall (1941) BMT (285) Leuk/Lymph (288) Pulm (1153) CNS/Dissem (175) Lin S-J et al, CID 2001; 32:358-66 Risk factors for fungal disease Candidiasis Aspergillosis -Broad -Granulocytopenia -Decreased neutrophil number -Decreased function -T-cell dysfunction -Hematologic malignancies -Organ allograft recipients -Immunosuppressants -Corticosteroids -AIDS spectrum antibiotics -Intravascular catheters -Abdominal surgery -Neoplastic diseases -Chemotherapy -Immunosuppressants Fungal infections today A major change in the occurence, diagnosis and management of invasive fungal infections has arisen in the recent years. Licensed antifungals: a dynamic drug class To be expected: Posaconazole isovuconazole – anidulafungin – micafungin … Voriconazole Caspofungin Lipid amphotericin products Itraconazole Fluconazole Ketoconazole Amphotericin B 1950 1960 Flucytosine 1970 1980 1990 2000 Outline Product Overview Spectrum Therapeutic indications Recommended dosages Pharmacokinetics Pharmacokinetic difficulties and problems Tolerability and safety Therapeutic drug monitoring? An ideal antifungal agent has… Broad spectrum of activity (yeasts and moulds) Rapidly and highly fungicidal, stable to resistance Potent in vivo activity (even in neutropenia) Good pharmacokinetics (AUC) Both oral and parenteral formulations Good penetration into all tissue compartments Low toxicity, minimal drug-drug interactions Cost effective Polyenes Amphotericin B Target: fungal cell membrane Ampho B binds ergosterol in the cell membrane • depolarisation: leakage of monovalent and divalent cations cell death • stimulates host immune response Amphotericin B Spectrum and Recommended dosage Spectrum: – very broad range of activity: most Candida and Aspergillus spp. – active against most fungi except A. terreus, Fusarium spp. Fungicidal Amphotericin B: 1 mg/kg IV (after a test dose of 1 mg) Lipid-based Amphotericin B – amphotericin B Lipid Complex: 5 mg/kg IV – liposomal amphotericin B: 3 mg/kg IV Amphotericin B Pharmacokinetics Low oral bioavailability: only IV administration Extensive distribution – High concentrations in liver, spleen, bone marrow No metabolism Renal excretion – Halflife: about 5 days Amphotericin B Tolerability and Safety chills, rigors, fever (during infusion) nausea, vomiting cardio/respiratory reactions phlebitis can be explained by mode of action: ampho B stimulates host immune response with release of inflammatory cytokines Amphotericin B Tolerability and Safety Nephrotoxicity: incidence: 49-65% Hypokalemia can be explained by mode of action: ampho B binds cholesterol in distal tubular membrane leading to wasting of Na+, K+ and Mg++ Amphotericin B Tolerability and Safety Nephrotoxicity has been shown to significantly increase: • Length of hospital stay • Treatment costs Prevention of nephrotoxicity • • • • • Fluids: saline, sodium bicarbonate Low-dose vasoconstrictors (e.g. dopamine) Alternate day dosing Infusion rates (conventional ampho B: at least 6 hrs) Lipid formulations Bates DW. CID 2001; 32: 686-93. Cagnoni PJ. J Clin Oncol 2000; 18: 2476-83. Greenberg RN. J Med Economics 2002; 2: 109-18. Azoles The azoles Target: fungal cell membrane Azoles inhibit ergosterol synthesis by inhibiting 14-α-demethylase toxic sterol intermediates accumulate in the cell membrane leading to enhanced cellular permeability and inhibition of fungal growth Inhibits also human CYP450-dependent enzymes playing an important role in human hormone synthesis or drug metabolism DRUG INTERACTIONS!!! Fluconazole Fluconazole Spectrum, therapeutic indications, dosage Spectrum: Candida spp. except C. krusei (C. glabrata: reduced susceptibility), Cryptococcus spp. Indications and dosage: Prophylaxis in neutropenic patients: fluco 200 mg Treatment of Candida-infections: Candidemia in nonneutropenic patients Fluco 400 mg + remove IV catheter ! C. glabrata-I: fluco 800 mg ! C. glabrata-R: caspofungin Invasive candidiasis (intra-abdominal/ postoperative) Fluco 400 mg (+ surgical drainage) Alternative caspofungin 70/50 mg IV Charlier C. JAC 2006; 57:384-410. Fluconazole Pharmacokinetics Bio-availability - > 90% - not dependent of gastric pH or food: IV-PO switch possible! Distribution - Metabolism - Excretion - extensive: Vd 0.7-1.0 L/kg - protein binding: 11% - CSF levels: 70% of plasma levels - good penetration in bone not metabolised 60-75% glomerular filtration: dose adjustments in decreased renal clearance - 8-10% feces - halflife: 27-34 hrs: OD administration, LD required - removed by dialysis Charlier C. JAC 2006; 57:384-410. Fluconazole Pharmacokinetics Pharmacokinetic problems? Majority unchanged renal excretion glomerular filtration+ tubular reabsorption Dose adjustments in severe renal failure Removed by dialysis: 100 mg extra dose after IHD Drug interactions: Inhibits CYP2C9, CYP2C19 and CYP3A4 cyclosporin – nephrotoxicity: TDM midazolam: excessive sedation phenytoin: TDM tacrolimus – nephrotoxicity, neurotoxicity: TDM warfarin: INR Rifampicin induces fluconazole metabolism: increase fluco dose with 25% Charlier C. JAC 2006; 57:384-410. Fluconazole Tolerability and Safety Generally very well tolerated: no adverse events Side effects only occur in high doses (>400 mg/day) – Common: headache, nausea, abdominal pain – Elevated AST/ALT levels: generally mild Reported in 10% of leukemia patients with fluco prophylaxis Reported in 20% of ICU patients with fluco prophylaxis – Rare: case reports of fulminant hepatitis – Very rare: neurotoxicity (high doses > 1200 mg/day), prolongation of the QT interval Charlier C. JAC 2006; 57:384-410. Fluconazole Therapeutic drug monitoring? No routine indications for measuring fluco levels - Predictable fluconazole PK and serum concentrations Charlier C. JAC 2006; 57:384-410. Voriconazole Voriconazole Spectrum of activity Invasive aspergillosis • fungicidal activity as great as ampho B Invasive candidiasis • C. glabrata? Fusarium, Penicillium, Scedosporium Cryptococcus • in vitro activity > flucytosine or fluconazole ! Zygomycetes: resistant to voriconazole • Breakthrough infections Mashmeyer G et al. Future Microbiol 2006; 1: 365-85. Voriconazole Recommended dosage Loading dose: 2 x 6mg/kg Maintenance dose: 2 x 4 mg/kg • Infusion over 1hr Adult Patients < 40 kg • Loading dose idem • Maintenance dose: 2 x 2 mg/kg or 2 x 100 mg Child A and B cirrhosis (Child C: no data) • Loading dose idem • Maintenance dose: 2 x 2 mg/kg or 2 x 100 mg Children (2-12 yrs) • 2 x 7 mg/kg Voriconazole Pharmacokinetics Bio-availability 96% Steady state - Distribution - Metabolism - extensive (Vd: 4.6 L/kg) - CSF concentration: 50% of plasma concentration: dosage increase by 50% - protein binding 58% - Elimination 5-6 days loading dose necessary! CYP2C9, CYP2C19, CYP3A4 major metabolite (72%): N-oxide -80% via urine -20% via feces Voriconazole Pharmacokinetics Voriconazole serum levels: high interindividual variability! !Difficult pharmacokinetics! Non-linear kinetics: saturable metabolism! Disproportional increase in plasma levels if dosage increased Half-life = dose dependent In children: linear pharmacokinetics: higher metabolising capacity – Dosage 7 mg/kg bid Genetic polymorphism CYP2C19 3 genotypes: extensive metabolizers, heterozygous extensive metabolizers, poor metabolizers PM especially in Asian population: 18-23% PM in Caucasion population: 3-5% Plasma levels up to 2-fold (HEM) or 4- fold (PM) higher! Purkins L et al. AAC 2002; 46:2546-53. Voriconazole Pharmacokinetics Extensive CYP-metabolism: drug interactions! Other drugs affecting voriconazole plasma levels – Contra-indicated with potent inducers Rifampicin, ritonavir, carbamazepine, phenobarbital – Dose adjustments needed if combined with phenytoin (5 mg/kg bid) Voriconazole affecting plasma levels of others (inhibition) – Contra-indicated with sirolimus, terfenadines, astemizole, cisapride, … – Dose adjustments needed if combined with Cyclosporin (- 50% ): if not, risk of nephrotoxicity Tacrolimus (- 66%): if not, risk of nephrotoxicity Voriconazole Pharmacokinetics Oral bio-availability affected if taken with food reduction oral bio-availability with > 20%! no studies if administered with enteral feeding on ICU – Stop enteral feeding 1hr before up to 2 hrs after administration – Administration 2x daily: 6 hrs without calory intake! Purkins L et al. Br J Clin Pharmacol 2003; 56 (S1): 17-23 Voriconazole Safety Visual disturbances: (20%) • Altered perception of light, photophobia, blurred vision, color vision changes: mechanism unknown • transient, infusion related • more in patients with higher levels - how to assess in sedated patients? Hepatotoxicity (13%) • AST, ALT, alkaline phosphatase, bilirubin elevations • AST, ALP and BILI abnormalities correlating with higher vorico plasma levels Phototoxicity (6%): erythema, Steven-Johnson syndrome, toxic epidermal necrolysis Neurological changes: confusion and hallucinations Voriconazole Safety Adverse effects of voriconazole – French pharmacovigilance database 4 year registration period detailed registration of cases causality assessment Results – – – – LFT abnormalities in 23% patients Visual disturbances in 18% of patients Skin rashes in 17% of patients Cardiovascular events (10%), hematologic disorders (8%) renal disturbances (4%) Eiden C. Ann Pharmacother 2007; 41:755-63 Voriconazole Tolerability and Safety Nephrotoxicity of SBECD – IV vials contain SBECD, a solubilizer in patients with moderate to severe renal failure (CrCl < 50 ml/min): accumulation of SBECD with potential nephrotoxicity (vacuolization of urinary epithelium) frequent problem in ICU patients: switch to oral formulation? Or other product? Von Mach MA et al. BMC Clin Pharamacol 2006; 6:6 Voriconazole Therapeutic drug monitoring? Complex pharmacokinetics High inter and intra- individual variability!! Serum levels correlated with efficacy/safety? FDA report - no correlation Smith. AAC 2006; - 28 patients, random plasma samples 50:1570-2. - progressive disease in 18 patients with levels < 2.05 µg/ml Trifilio S. BMT 2007; 40:451-6. - Denning D. CID 2002; 34: 56371. - 71 patients, trough plasma levels - 6 candidiasis cases in patients with levels < 2 µg/ml Herbrecht study - liver failure or liver toxicity in 6 out of 22 patients with levels > 6 µg/ml Optimal serum levels: 2-6 µg/ml – Well above MIC of Aspergillus/Candida spp. Voriconazole Therapeutic drug monitoring? TDM voriconazole – 52 adult patients: 181 samples – 25%: levels < 1mg/L Correlated with oral therapy Lack of response more frequent in this group – 31%: levels > 5.5 mg/L Correlated with omeprazole comedication 5 patients with neurotoxicity – 4 of 5 treated intravenously – TDM improves efficacy and safety – Proposed therapeutic interval 1-5.5 µg/ml Pascual A. CID 2008;46:201-211. Voriconazole Therapeutic drug monitoring? TDM … – in all patients? in patients with progressive disease? in patients exhibiting significant visual or hepatic toxicity? – in patients at risk of fluctuating plasma levels? drug interactions? changing hepatic and renal function? treated by mouth? ICU? – daily (cost-effectiveness)? – method? – dose adjustments? non-lineair kinetics! Goodwin M et al. JAC 2007. Epub Posaconazole Posaconazole Spectrum, therapeutic indication and dosage Spectrum: Candida spp. (less active C. glabrata), Aspergillus spp., C. neoformans, H. capsulatum, Zygomycetes Indications: Prophylaxis of invasive fungal infections in high-risk patients (SCTx – GvHD, AML-MDS) Treatment of IA, fusariosis, chromoblastosis, mycetoma, coccidiomycosis refractory to ampho B or itra Dosage: 200 mg 3 - 4x/day – Only available as oral suspension Posaconazole Pharmacokinetics Bio-availability -52-100% -Dependent on dosing frequency and intake with/without meal -Saturation in absorption if daily dose > 800 mg Distribution -Extensive (Vd: 2447L) -Tissue penetration: limited data - crosses BBB - distributes into bone and eye -Protein binding > 98% Metabolism -Primarily unchanged excretion -<30% metabolised as glucuronide conjugates (UGT 1A4) Elimination -Majority via feces as unchanged drug -Minimal renal elimination (14%) -Halflife 20 hr Schiller D et al. Clin Ther 2007; 29: 1862-1886 Posaconazole Pharmacokinetics Posaconazole levels: high interindividual variability! !Difficult pharmacokinetics! Absorption 2.6-4-fold higher if taken with a meal High-fat meals enhance absorption Cimetidine: gastric pH: 40% decrease in posaconazole AUC and Cmax Avoid concomitant use of histamine 2-blockers or PPIs! Mucositis? Schiller D et al. Clin Ther 2007; 29: 1862-1886 Goodwin M et al. JAC 2007. Epub. Posaconazole Pharmacokinetics Drug interactions Posaconazole inhibits CYP3A4 (not a substrate of CYP3A4) Tacrolimus: dose reduction with 66% Cyclosporine: dose reduction with 25% Increase in serum concentrations of benzodiazepines, calcium channel blockers, statines, TCA, nevirapine… Posaconazole is substrate of UGT 1A4 Induction by phenytoin: contra-indicated! Induction by rifabutin: contra-indicated! Schiller D et al. Clin Ther 2007; 29: 1862-1886 Goodwin M et al. JAC 2007. Epub. Posaconazole Pharmacokinetics Dosing in patients with hepatic impairment? posaconazole should be used with caution not studied using Child score Dosing in patients with renal impairment? Dose adjustment not necessary Use with caution in severe renal failure Schiller D et al. Clin Ther 2007; 29: 1862-1886 Goodwin M et al. JAC 2007. Epub. Posaconazole Tolerability and Safety Gastro-intestinal side effects - Abdominal pain, diarrhea, vomiting: 3-7% Elevated liver function tests Rash - Not correlated with elevated posa serum levels Schiller D et al. Clin Ther 2007; 29: 1862-1886 Goodwin M et al. JAC 2007. Epub. Posaconazole Therapeutic drug monitoring? Limited data available FDA approved product information: – association between posa levels and efficacy Proven (6%) or probable (3.8%) IFI if levels < 0.7 µg/ml Proven (1.8%) or probable (0%) IFI if levels > 0.7 µg/ml lower concentrations correlate with treatment failure – recommendations: ensurance of adequate plasma levels: – Administration of posaconazole with a meal – Avoidance of drug inducing agents – Monitoring for breakthrough infections Goodwin M et al. JAC 2007. Epub. Posaconazole Therapeutic drug monitoring? TDM in patients with: – Progressive disease – Suspected poor oral absorption (nausea, vomiting, mucositis, compliance) – Levels > 1.25 mg/L Goodwin M et al. JAC 2007. Epub. Caspofungin The echinocandins Target: fungal cell wall Echinocandines inhibit 1,3-beta-glucan synthase • depletion of glucan polymers: weak cell wall Caspofungin Spectrum of activity and indications Candida spp. (ex. C. parapsilosis) and Aspergillus spp. Not Cryptococcus as its cell wall does not contain ßD-glucan Not Fusarium spp., Zygomycetes Empirical therapy for presumed fungal infections in febrile, neutropenic patients Candidemia, intra-abdominal abscess, peritonitis Invasive aspergillosis if refractory or intolerant to other therapies Caspofungin Measurement of in vitro activity? – Candida spp.: minimal inhibitory concentration (MIC) Macroscopic growth inhibition Lowest concentration of the drug that results in inhibiting growth in 24 hours – Aspergillus spp.: minimal effective concentration (MEC) Microscopic endpoint Lowest concentration of the drug that results in formation of aberrantly growing hyphal tips Caspofungin Recommended dosage Loading dose: 70 mg Maintenance dose: 50 mg – Patients > 80 kg: 70 mg Child B liver cirrhosis – Loading dose: 70 mg – Maintenance dose: 35 mg Mistry GC. J Clin Pharmacol 2007; 47: 951. Caspofungin Pharmacokinetics Bio-availability <2%: only IV Distribution -Vd 4.5L - high levels in liver, spleen, kidney - equal levels in lung tissue - low levels in heart, skeletal muscle, brain -distribution phase determines clearance -protein binding: 96%: no elimination via IHD Metabolism - hydrolysis and N-acetylation: no active metabolites - not CYP450 dependent Excretion -via PK linear: 3 phases urine and faeces (only 2% unchanged) -distribution phase -elimination phase of 8 hrs -additional elimination phase with longer halflife of 27 hrs Caspofungin Pharmacokinetics Pharmacokinetic problems? Elimination based on tissue distribution No dose adjustments in renal insufficiency No CYP-mediated metabolism – No CYP-mediated drug interactions – No genetic polymorphisms Uptake via hepatic transporter: OATP OATP= organic anion transporting polypeptide Reduced uptake in patients with hepatic insufficiency – Dose reduction in Child B liver cirrhosis – No recommendations in Child C Drug interactions mediated by OATP? Sandhu P et al. DMD 2005; 33: 676-82. Caspofungin Pharmacokinetics OATP = organic anion transporting polypeptide • drug uptake transporter •Basolateral membrane of hepatocytes •Contributes to overall elimination of caspofungin • Cyclosporin and rifampicin are also substrates for OATP1B1 Caspofungin Pharmacokinetics Co-administration with cyclosporin – AUC caspo + 25% – Competitive inhibition at OATP? Co-administration with rifampicin – Inhibition and induction effect on caspo – First days: rifa blocks OATP – After continued dosing: rifa induces OATP Net effect: AUC caspo ↓: increase MD to 70mg/day Other inducers: efavirenz, nevirapine, dexamethasone, phenytoin, carbamazepin – Increase MD to 70 mg/day Caspofungin Tolerability and Safety Excellent safety and tolerability can be explained by mode of action: human cells do not have a cell wall Adverse events = unspecific drug reactions – Histamine-mediated: headache, fever, nausea – Elevation of hepatic enzyme levels AST, ALT and ALP < 5-fold ULN Caspofungin TDM in critically ill patients Caspofungin plasma concentrations in surgical intensive care units C24hr concentrations 40 SICU patients Altered drug plasma concentrations due to altered PK? Results: Trough levels: 0.52-4.08 µg/ml Literature (Stone studies): 1.12-1.78 µg/ml Higher in patients with low body weight (< 75 kg) Higher in patients with albumin concentration > 23.6 g/L ! Patients’ body weight varied from 48 – 108 kg >< every patient got LD 70 mg/ MD 50 mg! Nguyen TH et al. JAC 2007; 60:100-106. Anidulafungin - Micafungin Anidulafungin - Micafungin Spectrum, therapeutic indications and recommended dosage Anidulafungin Micafungin Spectrum -Candida spp. -Aspergillus spp. -Candida spp. -Aspergillus spp. Indications -Invasive candidiasis -Esophageal candidiasis -Prophylaxis for Candida infections in HSCT -Esophageal candidiasis Dosage LD: 200 mg MD: 100 mg -prophylaxis: 50 mg OD -treatment: 150 mg OD No Dose adjustement in hepatic impairment No Weight based dose adjustments No No Anidulafungin - Micafungin Pharmacokinetics Anidulafungin Micafungin Bioavailability Low, only IV administration Low, only IV administration Distribution -Rapid distribution halflife -Vd: 0.57 L/kg -Protein binding: 99% -No specific tissue distribution studies done -Vd: Metabolism -No hepatic metabolism -No CYP involvement -Metabolism by slow nonenzymatic, chemical degradation -No Elimination - Halflife : 24hrs - Via feces - Halflife: 13 hrs - Via feces, > 90% unchanged PK linear linear 0.39 L/kg -- Protein binding: 99% - poor CNS penetration hepatic metabolism -No CYP involvement -Breakdown by arylsulfatase and COMT Anidulafungin- Micafungin Pharmacokinetics anidulafungin micafungin Dose adjustments in hepatic insufficiency? No Studied in Child A,B,C: no increase in plasma levels No Not studied in Child C Dose adjustments in renal insufficiency/dialysis? No No No Small increase in anidula levels if combined with cyclosporine No Possibly mild inhibition of CYP3A with small increase in cyclosporin, sirolimus and nifedipin levels Drug interactions? Anidulafungin-Micafungin Tolerability and Safety Adverse reactions = mild Infusion (histamine-mediated) related reactions (especially at high infusion rates): flushing, pruritis, rash, urticaria Coagulopathy Diarrhoea, vomiting, nausea Hepatic enzyme elevation: ALT, ALP, bilirubin In 5-10% of patients Usually < 3-fold ULN Micafungin Warning EMEA – risk hepatocellular tumour formation • discontinuation if persistent elevation ALT/AST • consider alternative in patients with severe liver function impairment or chronic liver diseases or concomitant hepatotoxic therapy http://www.emea.europa.eu/humandocs/PDFs/EPAR/mycamine/H-734-PI-en.pdf Case report CASE I Man, 49 yrs old, 65 kg Medical history: – diabetes, insuline dependent – abuse: nicotine, ethyl (10 U/day) – weight loss: - 25 kg/2 months Admitted because of – hyperglycemia – fever, hypotension, leucopenia, thrombopenia Rx thorax: bilateral infiltrates Diagnosis: CAP: start Cefuroxim – amikacin – Elevated liver function tests (bili: 3.38 mg/dL): cirrhosis? – On day 8: high fever: switch AB into meropenem – fluconazol – Transfer UZ Leuven CASE I Man, 49 yrs old, 65 kg Admitted upon ICU – high fever, severe hypotension, respiratory distress: Intubation + mechanical ventilation Fluid resuscitation, noradrenalin, antibiotics New cultures Day 10 and 11: BA Aspergillus + Day 12: BAL Aspergillus +/ galactoBAL: 8.3 Serum galactomannan day 11: 3.2 Diagnosis: Invasive aspergillosis start Vfend IV LD 400 mg on day 11 Stop Diflucan CASE I Man, 49 yrs old, 65 kg At the same day: Decrease of renal function: start CVVH ! Vfend IV: accumulation of SBECD: switch PO? Auramin stain: + : tuberculosis! – Start TB therapy: ethambutol, pyrazinamid, moxifloxacin and rifampicin ! Vfend + Rifampicin = contra-indicated! Switch Cancidas Interaction with rifampicin! Dosage: LD 70 mg – MD 70 mg CASE II Female, 49 yrs old, 80 kg Medical history: – Henoch-Schönlein vasculitis R/ Medrol 64 mg during 1 month Hospital admission because of – anorexia, chills, sputa, respiratory insufficiency Suspicion of pneumonia: Augmentin CRP ↑: switch to Tazocin BAL: A. fumigatus/ serum GM 4.8: R/ Vfend tablets 2x400mg LD, 200 mg PO IHD - terminal renal insufficiency CASE II Female, 49 yrs old, 80 kg Day 6: Transfer to UZ Leuven - MICU Serum GM: 0.7/BA: fungi CT brain: cerebral aspergillosis – multiple lesions Ocular Aspergillus invasion Diagnosis: Pulmonary, cerebral, ocular IA Switch Vfend PO → IV + increase dose based on body weight: 2 x 320 mg Vfend intravitreal injection Switch Tazocin into Meronem (follow up GM) CASE II Female, 49 yrs old, 80 kg Day 12: switch Vfend IV → PO (suspension) Association of L-AmB high dose: 5 mg/kg Day 14: serum GM: 0.1 CT brain: worsening cerebral lesions CASE II Female, 49 yrs old, 80 kg Discussion – CNS aspergillosis Voriconazole = first line – standard dose or higher dose (penetration 50%)? Combination with L-AmB? – Initial Vfend dose: too low? Tablets vs. oral suspension (weight based dosing)? – Vfend IV vs. PO? PO ↔ critically ill patient, enteral feeding: absorption? IV ↔ accumulation of SBECD in patient with IHD – Encephalopathy due to brain accumulation of SBECD? – Encephalopathy due to high vorico levels? Final Remarks How to choose? Spectrum Likely or documented pathogen Site of infection Patient-specific factors Concomitant diseases Hepatic/renal function Toxicities Drug interactions with concomitant therapy IV/PO Cost/ Reimbursement criteria Conclusion Despite development of new antifungals during last decade mortality of IFI remains very high – optimalisation of diagnostics – improvement of knowledge on pharmacokinetics – role of TDM? avoid toxicity warrant effective drug concentrations