Midazolam injection is used before medical procedures and surgery to cause drowsiness, relieve anxiety, and prevent any memory of the event. It is also sometimes given as part of the anesthesia during surgery to produce a loss of consciousness. Midazolam injection is also used to cause a state of decreased consciousness in seriously ill people in intensive care units (ICU) who are breathing with the help of a machine. Midazolam injection is in a class of medications called benzodiazepines.