Cardiplot Drug Interactions

The antihypertensive effect of manidipine may be enhanced by the combination with diuretics, beta-blockers and other antihypertensive drugs. In vitro studies have shown that the potential inhibiting effect of manidipine on cytochrome P450 may be considered clinically irrelevant.
As occurs with other dihydropyridine calcium channel blockers, it is probable that manidipine metabolism is catalysed by the cytochrome P450 3A4. Since there are no in vivo interaction study available on the effects of cytochrome CYP3A4 inhibitors or inducers on the pharmacokinetics of manidipine, caution should be exercised when Cardiplot is administered with drugs which inhibit the CYP 3A4 enzyme, such as ketoconazole, itraconazole, or with drugs which induce CYP 3A4, such as phenytoin, carbamazepine, phenobarbital and rifampicin (see Precautions) and posology of manidipine should be adjusted if needed.
Caution is required in the concomitant prescription of manidipine and other CYP3A4 substrates, such as terfenadine, astemizole, quinidine and class III antiarrhythmics such as amiodarone (see Precautions).
Moreover, concomitant administration of calcium channel blockers in combination with digoxin may determine increased glucoside levels.
Other antihypertensive drugs: The antihypertensive effect of manidipine can be increased by the concomitant administration of diuretics, beta-blockers and, in general, any other antihypertensive drugs.
Alcohol: As for all vasodilatory antihypertensives, caution is mandatory if alcohol is consumed concomitantly, as this can enhance their effects.
Grapefruit juice: Grapefruit juice seems to inhibit the metabolism of dihydropyridines, with a resulting increase in its systemic bioavailability and its hypotensive effect. Manidipine must therefore not be administered with grapefruit juice.
Oral hypoglycaemics: No interactions with oral hypoglycaemic agents have been noticed.
Amifostine: Increased risk of the antihypertensive effect.
Tricyclic antidepressant/antipsychotics: Increased antihypertensive effect and increased risk of orthostatic hypotension.
Baclofen: Potentiation of antihypertensive effect. Monitoring of blood pressure and renal function, and dose adaptation of the antihypertensive if necessary.
Corticosteroids, tetracosactide: Reduction of antihypertensive effect (salt and water retention due to corticosteroids).
Alpha-blockers (prazosin, alfuzosin, doxazosin, tamsulosin, terazosin): Increased antihypertensive effect and increased risk of orthostatic hypotension.