Shoulder stiffness: a common adverse effect of HMG-CoA reductase inhibitors in women?

Muscle symptoms are known as adverse effects of HMG-CoA reductase inhibitors but their incidence is reported to be low. We treated a case of shoulder stiffness related to such a drug, which prompted us to preliminarily survey its incidence. We found that nearly one-tenth of women (6/66) taking such drugs reported drug-related shoulder stiffness. Shoulder stiffness is a very common symptom, while drug-induced shoulder stiffness is generally unknown. Many cases involving such an adverse effect may thus be overlooked. We present 2 typical cases here.