Atorvastatin Calcium-channel blockers

CALCIUM CHANNEL BLOCKERS STATINS t plasma levels of atorvastatin, lovastatin and simvastatin case reports of myopathy when atorvastatin and simvastatin are co-administered with diltiazem or verapamil Uncertain, but postulated to be due to inhibition of CYP3A4-mediated metabolism of statins in the intestinal wall. Also, diltiazem and verapamil inhibit intestinal P-gp, which may t the bioavailability of statins Watch for side-effects of statins. It has been suggested that the dose of simvastatin should not exceed 20 mg when given with verapamil, and 40 mg when given with diltiazem... 

D Rifampin significantly reduces the plasma concentrations of the calcium channel blockers verapamil, diltiazem, and nifedipine. Diltiazem is a substrate of Gi P3A4 and rifampin is an inducer of CYP3A4. Rifampin does not interact with metoprolol, aspirin, pravastatin, or nitroglycerin. However, if the patient had been on another HMG-CoA reductase inhibitor such as atorvastatin, lova-statin, or simvastatin instead of pravastatin, rifampin would have reduced the plasma concentrations of these agents since they are also metabolized via CYP3A4. 

Modafinil is an inducer of the cytochrome P450 isoenzyme CYP3A4. The manufacturers therefore predict that it may reduce the levels of drugs that are CYP3A4 substrates. They specifically name the protease inhibitors, buspirone, calcium-channel blockers, ciclosporin, midazolam, and the statins [note that only some statins, namely atorvastatin, lovastatin and... 

The manufacturers of amlodipine state that it does not affect the pharmacokinetics of atorvastatin. They also note that no clinically significant interactions were seen in clinical studies in which atorvastatin was used with antihypertensives, including unspecified calcium-channel blockers. However, they do warn that drugs that are metabolised by the cytochrome P450 isoenzyme CYP3A4 (e.g. calcium-channel blockers) do have the potential to interact. ... 

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