LANT
warfarin ↑ or ↓ warfarin Concentrations of warfarin may be altered when co-administered with telaprevir. The international normalized ratio (INR) should be monitored when warfarin is co-administered with telaprevir.
ANTICONVULSANTS
carbamazepine
phenobarbital
phenytoin ↓ telaprevir
↑ carbamazepine
↑ or ↓ phenytoin
↑ or ↓ phenobarbital
Concentrations of the anticonvulsant may be altered and concentrations of telaprevir may be decreased. Caution should be used when prescribing carbamazepine, phenobarbital, and phenytoin.
Telaprevir may be less effective in patients taking these agents concomitantly.
Clinical or laboratory monitoring of carbamazepine, phenobarbital, and phenytoin concentrations and dose titration are recommended to achieve the desired clinical response.
ANTIDEPRESSANTS
escitalopram* ↔ telaprevir
↓ escitalopram Concentrations of escitalopram were decreased when co-administered with telaprevir. Selective serotonin reuptake inhibitors such as escitalopram have a wide therapeutic index, but doses may need to be adjusted when combined with telaprevir.
desipramine
trazodone ↑ desipramine
↑ trazodone Concomitant use of trazodone or desipramine and telaprevir may increase plasma concentrations of trazodone or desipramine which may lead to adverse events such as nausea, dizziness, hypotension and syncope. If trazodone or desipramine is used with telaprevir, the combination should be used with caution and a lower dose of trazodone or desipramine should be considered.
ANTIFUNGALS
ketoconazole*
itraconazole
posaconazole
voriconazole ↑ ketoconazole
↑ telaprevir
↑ itraconazole
↑ posaconazole
↑ or ↓ voriconazole Ketoconazole increases the plasma concentrations of telaprevir. Concomitant systemic use of itraconazole or posaconazole with telaprevir may increase plasma concentration of telaprevir.
Plasma concentrations of itraconazole, ketoconazole, or posaconazole may be increased in the presence of telaprevir. When co-administration is required, high doses of itraconazole or ketoconazole (greater than 200 mg/day) are not recommended.
Caution is warranted and clinical monitoring is recommended for itraconazole, posaconazole and voriconazole.
QT interval prolongation and Torsade de Pointes have been reported with voriconazole and posaconazole. QT interval prolongation has been reported with ketoconazole.
Due to multiple enzymes involved with voriconazole metabolism, it is difficult to predict the interaction with telaprevir. Voriconazole should not be administered to patients receiving telaprevir unless an assessment of the benefit/risk ratio justifies its use.
ANTI GOUT
colchicine ↑ colchicine Patients with renal or hepatic impairment should not be given colchicine with telaprevir, due to the risk of colchicine toxicity. A reduction in colchicine dosage or an interruption of colchicine treatment is recommended in patients with normal renal or hepatic function.
Treatment of gout flares: co-administration of colchicine in patients on telaprevir:
0.6 mg (1 tablet) for 1 dose, followed by 0.3 mg (half tablet) 1 hour later. Not to be repeated before 3 days.
If used for prophylaxis of gout flares: co-administration of colchicine in patients on telapr
