Atorvastatin and Nefazodone interaction

LIPITOR plasma levels can be significantly increased with concomitant administration of inhibitors of CYP3A4 and transporters.

Table 2: Drug Interactions that may Increase the Risk of Myopathy and Rhabdomyolysis with LIPITOR Cyclosporine or Gemfibrozil Clinical Impact: Atorvastatin plasma levels were significantly increased with concomitant administration of LIPITOR and cyclosporine, an inhibitor of CYP3A4 and OATP1B1 [see Clinical Pharmacology (12.3) ] .

Anti-Viral Medications Clinical Impact: Atorvastatin plasma levels were significantly increased with concomitant administration of LIPITOR with many anti-viral medications, which are inhibitors of CYP3A4 and/or transporters (e.g., BCRP, OATP1B1/1B3, P-gp, MRP2, and/or OAT2) [see Clinical Pharmacology (12.3) ] .

HMG-CoA Reductase Inhibitors – When single 40 mg doses of simvastatin or atorvastatin, both substrates of CYP3A4, were given to healthy adult volunteers who had received nefazodone hydrochloride, 200 mg BID for 6 days, approximately 20 fold increases in plasma concentrations of simvastatin and simvastatin acid and 3 to 4 fold increases in plasma concentrations…

Rhabdomyolysis has been observed in patients receiving HMG-CoA reductase inhibitors administered alone (at recommended dosages) and in particular, for certain drugs in this class, when given in combination with inhibitors of the CYP3A4 isozyme.

Caution should be used if nefazodone is administered in combination with HMG-CoA reductase inhibitors that are metabolized by CYP3A4, such as simvastatin, atorvastatin, and lovastatin, and dosage adjustments of these HMG-CoA reductase inhibitors are recommended.

Since metabolic interactions are unlikely between nefazodone and HMG-CoA reductase inhibitors that undergo little or no metabolism by the CYP3A4 isozyme, such as pravastatin or fluvastatin, dosage adjustments should not be necessary.

This is consistent with the interactions observed between nefazodone and triazolam, alprazolam, buspirone, atorvastatin, and simvastatin, drugs metabolized by this isozyme.