To the Editor: Hydroxymethylglutaryl coenzyme-A (HMG Co-A) reductase inhibitors (or statins) are widely prescribed, and any class-specific side effect has the potential to affect many thousands of patients. The statin drugs are well recognised as a cause of mild and usually transient hepatitis.1-3 Cholestatic liver injury has been reported with simvastatin4 and atorvastatin,5 but pravastatin has only been implicated as a cause in one report.6

We report a 64-year-old woman who was twice treated with pravastatin sodium and who, on both occasions, demonstrated cholestasis, which, at its peak, was associated with minimal hepatocellular injury.

Our patient presented to the liver clinic of the John Hunter Hospital in 2001 for investigation of abnormal liver function test results. She was taking diltiazem, aspirin, irbesartan plus hydrochlorothiazide, and pravastatin as therapy for hypertension and hyperlipidaemia. She consumed less than 10 g alcohol per week. Liver function tests showed a predominant elevation of alkaline phosphatase and γ-glutamyltransferase, with a minimal rise in alanine and aspartate aminotransferases, a picture consistent with cholestasis rather than hepatocellular disease (see Box). She had started taking pravastatin in the three months preceding her referral, and commented that when she was taking the drug in the previous year she had also had abnormal liver test results. Her liver function test results in 1998 were normal.

Two ultrasound examinations of the liver, performed after five months of taking pravastatin in the first period and two months after beginning her second period of therapy, showed normal liver size and echogenicity, and no sign of obstructive liver disease. Tissue antibodies, viral studies for hepatitis viruses, α1-antitrypsin and iron studies were all either normal or negative. Renal function was normal throughout. She had no biochemical evidence of impaired hepatocellular function, and for this reason liver biopsy and endoscopic retrograde cholangiopancreatography were not undertaken.

In view of the association the patient made between previously ceasing therapy with the drug (because she felt unwell) and improving liver function, therapy (which was recommenced by the cardiologist for hyperlipidaemia) was again suspended and within two months liver test results improved markedly.

We believe that in the absence of other markers of liver disease and with improvement of liver function on both occasions that therapy with pravastatin was suspended, it is likely that this patient has twice developed a cholestatic response to pravastatin.