Midazolam, marketed under the trade names Versed among others, is a medication used for anesthesia, procedural sedation, trouble sleeping, and severe agitation. It works by making people sleepy, decreasing anxiety, and causing a loss of ability to create new memories. It is also useful for the treatment of seizures. Midazolam can be given by mouth, intravenously, by injection into a muscle, sprayed into the nose, or in the cheek. When given intravenously, it begins working, typically, within five minutes; when injected into a muscle, it can take fifteen minutes to begin working. Effects last for between one and six hours.
Side effects can include a decrease in efforts to breathe, low blood pressure, and sleepiness. Tolerance to its effects and withdrawal syndrome may occur following long-term use. Paradoxical effects, such as increased activity, can occur especially in children and older people. There is evidence of risk when used during pregnancy but no evidence of harm with a single dose during breastfeeding. It is of the benzodiazepine class and works through the GABA neurotransmitter.
Midazolam first came into use in 1976. It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. Midazolam is available as a generic medication and is not very expensive. The wholesale cost in the developing world of a vial is about 0.35 USD. In many countries, it is a controlled substance.