Albendazole Interactions
- Carbamazepine
- Cimetidine
- Clozapine
- Dexamethasone
- food
- Fosphenytoin
- grapefruit juice
- Mexiletine
- Olanzapine
- Phenobarbital
- Phenytoin
- Praziquantel
- Ropinirole
- Tacrine
- Theophylline, Aminophylline
Tricyclic antidepressants
- Warfarin
Albendazole Interactions
Albendazole has been shown to induce the hepatic CYP1A microsomal enzymes (e.g., CYP1A1, CYP1A2) in human hepatoma cells. While the pharmacokinetics of theophylline (given as aminophylline 5.8 mg/kg IV infused over 20 minutes) were unchanged following a single oral dose of albendazole (400 mg PO) in 6 healthy subjects; no data are available for repeated coadministration of these drugs. It is possible that the prescription of albendazole may result in an increased clearance of theophylline via induction of CYP1A enzymes. Conversely, the discontinuation of albendazole therapy may result in a reduced clearance of theophylline, leading to an increase in serum theophylline concentrations. Theophylline serum concentrations and the patient’s clinical status should be monitored carefully when albendazole is prescribed and on discontinuation of albendazole therapy.
Albendazole induces cytochrome P450 1A (CYP1A) and although not studied, may induce the metabolism of clozapine, mexiletine, olanzapine, ropinirole, tacrine, tricyclic antidepressants, and R-warfarin. Patients receiving these combinations should be closely monitored when albendazole is prescribed, as albendazole may increase the clearance of the listed drugs. Conversely, the discontinuation of albendazole therapy may result in a reduced clearance of the listed drugs, leading to an increase in serum concentrations. The patient’s clinical status should be monitored carefully when albendazole is prescribed and on discontinuation of albendazole therapy.
Concomitant administration of albendazole with dexamethasone increases the plasma concentration of albendazole sulfoxide, presumably via reduction in albendazole sulfoxide clearance. Steady-state trough concentrations of albendazole sulfoxide were increased approximately 56% in patients receiving dexamethasone (8 mg PO with each dose of albendazole 15 mg/kg/day). Systemic corticosteroids are often administered concomitantly with albendazole for the treatment of neurocysticercosis, so this interaction is not thought to be clinically harmful.
Cimetidine administration with albendazole has been reported to increase albendazole bioavailability. Concentrations of albendazole sulfoxide were increased in bile and cystic fluid about 2-fold in patients with hydatid cyst disease treated with cimetidine (10 mg/kg/day) concomitantly with albendazole compared to administration of albendazole alone. Albendazole sulfoxide plasma concentrations were unchanged 4 hours after dosing. More data are needed to elucidate the clinical consequence of this interaction; it is hypothesized that cimetidine may enhance therapeutic effectiveness of albendazole, but there are no clinical data. It is also possible that combined therapy might increase the risk of dose-related side effects of albendazole. Patients should not take cimetidine concurrently with albendazole unless their prescriber has so advised.
Clinicians should be aware that albendazole may interact with certain food items. Albendazole tablets should be administered with a fatty meal (40 g) to increase bioavailability and ensure therapeutic efficacy. Grapefruit juice appears to increase the bioavailability of albendazole via reduction of CYP3A4-mediated metabolism in the intestinal mucosa. The AUC and Cmax of albendazole increased approximately 3-fold and T1/2 was shortened by 46% when administered with grapefruit juice. The clinical consequence of the interaction is not clear, but it is possible that patients taking albendazole with grapefruit juice may experience increased adverse effects. Patients should be advised to not significantly alter their intake of grapefruit juice during albendazole therapy.
Praziquantel is not commonly combined with albendazole therapy, such use is experimental for indications such as hydatid cyst disease. Praziquantel pharmacokinetics do not appear to be affected by coadministration of albendazole. It appears, however, that praziquantel increases albendazole bioavailability. The AUC of albendazole sulphoxide (the active metabolite of albendazole) appears to increase by roughly 4.5-fold when administered with praziquantel, and 12-fold when given with both praziquantel and food. The mean Cmax and AUC of albendazole sulfoxide were increased by about 50% in healthy subjects receiving praziquantel (40 mg/kg) concomitantly with albendazole versus those patients receiving albendazole (400 mg dose) alone. The mechanism of the interaction is not clear. More data are needed to elucidate the clinical consequence of this interaction; there are limited clinical data regarding combined use. Use albendazole cautiously in combination with praziquantel.
Antiepileptic drugs (AEDs) are often administered concomitantly with albendazole for the treatment of neurocysticercosis. Enzyme-inducing antiepileptic drugs (e.g. carbamazepine, phenytoin or fosphenytoin, phenobarbital) appear to induce the oxidative metabolism of albendazole. Notably, a significant reduction in the plasma concentration of the active albendazole sulfoxide metabolite may occur. It is not clear if these pharmacokinetic interactions affect the therapeutic efficacy of albendazole in the treatment of neurocysticercosis. Monitor patient clinical response closely during treatment.
[ Last revised: 4/1/2004 11:27:00 AM ]
References
. Nagy J, Schipper HG, Koopmans RP, et al. Effect of grapefruit juice or cimetidine coadministration on albendazole bioavailability. Am J Trop Med Hyg 2002;66:260 - 3.
. Lanchote VL, Garcia FS, Dreossi SA, et al. Pharmacokinetic interaction between albendazole sulfoxide enantiomers and antiepileptic drugs in patients with neurocysticercosis.Ther Drug Monit 2002;24:338 - 45.
. Homeida M, Leahy W. Copeland S, et al. Pharmacokinetic interaction between praziquantel and albendazole in Sudanese men. Ann Trop Med Parisitol 1994;88:551 - 9.
. Albenza® (albendazole) package insert. Research Triangle Park, NC: GlaxoSmithKline; 2001 Sept.
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