Ephedrine Medication Description DescriptionEphedrine is a medication and stimulant. It is often used to prevent low blood pressure during spinal anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred treatment. It is of unclear benefit in nasal congestion. Molar mass: 165.24 g/mol Formula: C10H15NO CAS ID: 299-42-3 Duration of action: IV/IM (60 min), by mouth (2 h to 4 h) Onset of action: IV (seconds), IM (10 min to 20 min), by mouth (15 min to 60 min) Elimination half-life: 3 h to 6 h Metabolism: minimal liver