PLASMA COENZYME-Q (UBIQUINONE) CONCENTRATIONS IN PATIENTS TREATED WITH SIMVASTATIN

Plasma coenzyme Q (CoQ) was measured in 20 hyperlipidaemic patients tr eated with diet and simvastatin (an inhibitor of 3-hydroxy-3-methylglu taryl coenzyme A (HMG CoA) reductase); 22 hyperlipidaemic patients tre ated with diet with alone; and 20 normal controls. Patients treated wi th simvastatin had a significantly lower plasma CoQ and CoQ: cholester ol ratio than either patients receiving diet alone or normal controls. Use of simvastatin was inversely and independently correlated with bo th CoQ (p < 0.0001) and CoQ: cholesterol ratio (p < 0.01). There was a significant inverse association between CoQ and dose of simvastatin ( p < 0.001). It is concluded that simvastatin may lower the plasma CoQ concentration and this may be greater than the reduction in cholestero l. The possible adverse effect of simvastatin on the metabolism of CoQ may be clinically important and requires further study.