With the simultaneous use of verapamil:
- increases the AUC (area under the concentration-time curve) of carbamazepine in patients with persistent partial epilepsy (risk of side effects such as diplopia, headache, ataxia and dizziness).
- increases AUC, Css (clearance) and Cmax (maximum concentration of the drug) cyclosporine.
- increases AUC and Cmax of glibenclamide.
- increases the concentration of sirolimus and tacrolimus.
- significantly increases AUC and Cmax buspirone and midazolam.
- increases the concentration of theophylline (due to lower clearance), ethanol (and lengthens its effect), the concentration of quinidine (the risk of pronounced reduction in blood pressure).
- can increase the concentration of atorvastatin and lovastatin.
- increases significantly AUC and Cmax simvastatin.
- increases AUC and Cmax of almotriptan.
- increases the concentration of cardiac glycosides (requires careful observation and a lower dose of glycosides).
- increases AUC and Cmax metoprolol and propranolol in patients with angina.
- increases the plasma concentration of colchicine (substrate for CYP3A and p-glycoprotein).
- when ingested significantly increases AUC and Cmax doxorubicin.
- slightly increases the AUC of imipramine; does not affect the concentration of the active metabolite, desipramine.
- increases the Cmax of prazosin and terazosin and AAC terazosin.
-
inhibitors of CYP3A (including
erythromycin,
ritonavir and other antiviral HIV drugs), telithromycin increase plasma concentrations of verapamil.
- grapefruit juice increases AUC and Cmax R- and S-isomer verapamil.
- cimetidine increases the bioavailability of verapamil by almost 40-50% (due to a decrease in hepatic metabolism), so it may be necessary to reduce the dose of the latter.
- rifampicin can significantly reduce bioavailability (up to 92%), as well as AUC and Cmax verapamil.
- Phenobarbital increases the clearance of verapamil 5 times.
- sulfinpyrazone increases the clearance of verapamil by about 3 times and reduces bioavailability (60%).
- preparations of St. John's wort penetrate the AUC R- and S-isomers of verapamil and, respectively, Cmax.
- while simultaneous use with inhalation anesthetics increases the risk of bradycardia, atrioventricular blockade, heart failure.
- a combination with beta-blockers can lead to an increase in the negative inotropic effect, an increased risk of developing atrioventricular conduction disorders, bradycardia (the administration of verapamil and beta-blockers should be performed at intervals of several hours)
- prazosin and other alpha-blockers, as well as other antihypertensive agents (angiotensin-converting enzyme inhibitors, vasodilators, diuretics, beta-blockers) intensify the hypotensive effect.
- disopyramide and flecainide should not be administered within 48 hours or 24 hours after the use of verapamil (summation of a negative inotropic effect, up to a lethal outcome).
- increases the risk of neurotoxic effect of lithium preparations.
- strengthens the action of peripheral muscle relaxants (a change in the dosage regimen may be required).
- while concomitant use with acetylsalicylic acid showed a slightly greater increase in bleeding time than with acetylsalicylic acid alone.
- carbamazepine and lithium increases the risk of neurotoxic effects.
-
antiarrhythmics, beta-blockers (more severe atrioventricular block, more significant heart rate reduction, development of heart failure and increased arterial hypotension). Patients taking digitalis preparations,
quinidine, disopyramide, flecainide and other artiarrhythmic drugs, must be carefully observed.