SIMVASTATIN OR LOVASTATIN

Statins that are largely metabolised by CYP3A4 have their levels greatly raised by azoles that are potent inhibitors of this isoenzyme. The drug pairs that are affected by this interaction are:

lovastatin with itraconazole (20-fold rises seen)

lovastatin with ketoconazole

simvastatin with itraconazole (17-fold rises seen)

simvastatin with ketoconazole

atorvastatin, lovastatin or simvastatin with posaconazole (predicted by the manu-
facturers)
This interaction has resulted in severe muscle toxicity, including rhabdomyolysis, in a number of cases.
Concurrent use of itraconazole, ketoconazole or posaconazole with simvastatin or lovastatin is contraindicated. The manufacturers of posaconazole also contra- indicate atorvastatin. If a short course of an azole is essential, the statin should be temporarily withdrawn. For voriconazole, see atorvastatin, above.

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