Ephedrine is a drug related to adrenaline that causes constriction of blood vessels and widening of bronchial passages. It is used mainly as a nasal decongestant, being administered as nasal drops or included with other ingredients in oral cold remedies, but is also injected intravenously to reverse hypotension following epidural or spinal anesthesia. It may cause nausea, insomnia, headache, and dizziness.