Escape phenomenon occurs by lowering cholesterol with a hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor in patients with familial hypercholesterolemia.

3 beta-Hydroxycompactin, a hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, is a useful drug as an anticholesterolemic agent. However, in some patients with familial hypercholesterolemia, treatment was associated with a rebound in serum cholesterol concentration when the dose was increased from 10 to 40 mg/day. The rebound was more remarkable when the basal cholesterol level was lowered by cholestyramine and/or probucol. The phenomenon seems to be due to an induction of HMG-CoA reductase as seen in some animals and cultured cells.