Isoxsuprine 40mg (SR) is a sustained-release formulation of Isoxsuprine, a vasodilator and beta-adrenergic agonist. This medication is used to improve blood circulation and relieve smooth muscle spasms. It is typically prescribed for conditions such as peripheral vascular disease, Raynaud’s phenomenon, and claudication, where restricted blood flow to the limbs leads to pain and discomfort. The sustained-release (SR) formulation allows for gradual release of the medication over time, helping to maintain steady therapeutic levels and provide prolonged effects. Isoxsuprine works by relaxing blood vessels to improve blood flow, which can help alleviate symptoms like leg cramps, pain, and tingling. It may also be used in cases of premature labor to relax uterine muscles. Caution is needed in patients with heart conditions or hypertension, and it should be used under medical supervision.