Carbamazepine Amlodipine

Clinically important, potentially hazardous interactions with amlodipine, anisindione, anticoagulants, aprepitant, atorvastatin, barbiturates, benzodiazepines, butabarbital, carbamazepine, chlordiazepoxide, clarithromycin, clonazepam, dorazepate, corticosteroids, cyclosporine, dexamethasone, diazepam, dicumarol, erythromycin, ethotoin, felodipine, flurazepam, fluvastatin, fosphenytoin, isradipine, itraconazole, ketoconazole, lorazepam, lovastatin, mephenytoin, mephobarbital, midazolam, nicardipine, nifedipine, nimodipine, nisoldipine, oxazepam, pentobarbital, phenobarbital, pimozide, pravastatin, primidone, quazepam, rifampin, secobarbital, simvastatin, St John s wort, temazepam, warfarin... 

Both diltiazem and verapamil can increase serum carbamazepine levels causing toxicity. Limited evidence suggests that amlodipine and nifedipine do not affect carbamazepine levels. A single case report describes neurological toxicity in a patient taking phenytoin and carbamazepine with isradipine. 

Nifedipine 20 mg twice daily for 2 weeks did not affect the steady-state carbamazepine levels in 12 epileptic patients. Similarly, a retrospective study of 5 patients suggested that nifedipine does not usually raise carbamazepine levels or cause toxicity.A man had a marked rise in serum carbamazepine levels when nifedipine was replaced by diltiazem. When diltiazem was replaced by amlodipine, his carbamazepine levels returned to normal, suggesting that neither nifedipine nor amlodipine interact with carbamazepine. " Another patient had no change in carbamazepine levels when also given nifedipine. ... 

Information about the effects of calcium-channel bloekers on ear-bamazepine is limited, but what is known indicates that if carbamazepine is given with verapamil or diltiazem, the carbamazepine dosage may possibly need to be reduced to avoid toxicity. A 50% reduction in the dose of carbamazepine has been suggested if diltiazem is to be used. Nifedipine and amlodipine normally appear to be non-interaeting alternatives. Oxear-bazepine appears to be a non-interaeting alternative for carbamazepine. 

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