Pharmacology

Midazolam hydrochloride, or Versed, is in a class of drugs called benzodiazepines which are sedatives, hypnotics and muscle relaxants.  Versed works by decreasing the nerve cell activity in areas of the brain associated with anxiety.  Scientists think that anxious people have overactive cell activity in these areas. 

Benzodiazepines affect the activity of a chemical that transmits impulses across nerve synapses called Gamma-AminoButyric Acid (GABA). In mammals, about 40% of all brain synapses are thought to be GABA-related.  GABA is an inhibitory neurotransmitter and an ion channel which allows passage of chloride ions.  The opening and closing of this channel regulates the flow of chloride ions which changes membrane potential and controls the effect of GABA.  Benzodiazepines work by increasing the effects of GABA at these GABA receptors.

Benzodiazepines stereospecifically bind to receptors on a large protein complex on neurons.  This complex also contains the GABA receptors. It is believed that benzodiazepine receptors in the brain stem control the sedative effects while receptors in the forebrain control the amnesiac effects of benzodiazepines.

Current thinking is that there are at least two types of benzodiazepine receptors in the brain:  Type 1 Receptors are in the cerebellum and Type 2 Receptors are most concentrated in the brain stem areas.  The evidence for the existence of these different receptor types is based on different types of messenger RNA which are coded for GABA receptor sites.

The effects of Versed, like other benzodiazepines, are a decrease in activity in the central nervous system, respiratory system and cardiovascular system.   In addition, Versed produces very short-term amnesia.