Cimetidine
Adverse Effect: Increased adverse effects of terbinafine (diarrhea, GI symptoms, headache, liver test abnormalities) Clinical Management: Monitor patient response and adjust dosage of terbinafine during combined treatment with cimetidine. Observe for signs of terbinafine toxicity (diarrhea, GI symptoms, headache, liver test abnormalities).
Nortriptyline
Adverse Effect: Increased risk of nortriptyline toxicity (fatigue, vertigo, loss of appetite) Clinical Management: Closely monitor patients receiving nortriptyline and terbinafine concurrently for signs of tricyclic intoxication, including drowsiness, vertigo, and loss of appetite. A nortriptyline plasma level may be helpful if toxicity is suspected.
Rifampicin
Adverse Effect: decreased therapeutic response to terbinafine Clinical Management: Monitor patient response and adjust dosage of terbinafine during combined treatment with rifampin.
Terfenadine
Adverse Effect: Minor increases in terbinafine serum concentrations Clinical Management: No known alterations in drug therapy are needed during concomitant administration of terfenadine and terbinafine.
Warfarin
Adverse Effect: an alteration of warfarin efficacy Clinical Management: Patients prescribed terbinafine and warfarin should be monitored for signs of excessive bleeding and also for signs of decreased warfarin efficacy. Prothrombin times and international normalized ratios (INRs) should also be closely followed, and the dose of warfarin should be adjusted as necessary |