Primidone Doxycycline

Noninterfering amikacin, amiloride, amoxicillin, ampicillin, cephalexin, doxycycline, ethosuximide, gentamicin, hydrochlorothiazide, netilmicin, phenacetin, phenemal, phen-3d oin, primidone, sisomicin, tetracycline, tobramycin... 

Similar results were found in 16 other patients taking various combinations of phenytoin, carbamazepine, primidone or phenobarbital. The serum doxycycline levels of almost all of them fell below 0.5 micrograms/mL during the 12 to 24 hour period following their last dose of doxycycline 100 mg. Tetracycline, methacycline, oxytetracycline, demeclocycline and chlortetracycline levels were not significantly affected by these antiepilepties. Other studies confirm this interaction between some barbiturates (amobarbital, pentobarbital, phenobarbital) and doxycycline. ... 

Carbamazepine levels are increased by CYP3A4 inhibitors (cimetidine, macrolides, diltiazem, fluoxetine, ketoconazole, verapamil, valproate) levels are decreased by CYP3A4 inducers (cisplatin, doxorubicin, felbamate, phenobarbital, phenytoin, primidone, rifampin, theophylline). Carbamazepine may increase levels of clomipramine, phenytoin, and primidone and lithium toxicity may decrease levels of phenytoin, warfarin, oral contraceptives, doxycycline, theophylline, haloperidol, alprazolam, clozapine, ethosuximide, and valproate may interfere with other anticonvulsants. 

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