Benzodiazepines (benzos) are drugs that are frequently prescribed to treat anxiety and insomnia. Doctors also use them to help patients manage seizures, muscle spasms, panic disorders, and alcohol withdrawal.
Some well-known benzos include diazepam (Valium), lorazepam (Ativan), alprazolam (Xanax), and zoldipem (Ambien). But no matter how these different brands are marketed, all benzos produce five major effects that are used for medical treatment: anxiety relief, sleep induction, muscle relaxation, anticonvulsant, and memory impairment (useful in sedation for surgical procedures). Depending on the individual drug makeup, these different effects are exerted in varying degrees.
Benzodiazepines have a powerful effect on almost every aspect of brain and body function. They work by enhancing the effect of a neurochemical called gamma aminobutyric acid (GABA).
All communication in the brain involves brain cells (neurons) talking to each other across synapses – the tiny gaps between individual neurons. How do neurons send this information? By releasing chemical messengers called neurotransmitters, which travel across the synapses and bind to specific receptor sites on the receiving neurons (like a lock and key). Depending on the neurotransmitter’s message, the receptor opens or closes its “gate”, which either allows or stops the flow of electrically charged atoms (ions) into and out of the neuron. This will either excite or inhibit the neuron’s usual biological activity.
GABA is a neurotransmitter that tells cells to either slow down or stop firing (it is an inhibitory neurotransmitter). GABA sends its message by reacting with a special GABA-receptor site on the outside of a neuron, called the GABA receptor-chloride channel complex. By binding to the receptor site, GABA causes the chloride “gate” to open and allow chloride ions to flow through. This makes the neuron highly negative inside and decreases its ability to fire.
GABA makes the neuron less responsive to other neurotransmitters that would normally excite it, like norepinephrine (which controls heart rate, respiratory rate, and blood pressure), serotonin (which affects emotions – decreased levels cause depression), and dopamine (which affects emotions – increased levels cause euphoria, excitement, and infatuation).
This natural GABA effect is amplified by benzodiazepines. GABA receptors have subunits that can combine with benzos and boost the GABA actions. The benzo will increase the frequency of the opening of the chloride “gate” and increase the amount of chloride ions coming through, further slowing down the cell. They make the neurons even more resistant to excitation, resulting in the typical benzo effects, which are similar to the effects of alcohol.
(Sources: Lehne, R.A. (2010). Pharmacology for nursing care (7th ed.). St. Louis, MO: Saunders Elsevier; Myers, D.G. (2010). Psychology (9th ed. in modules). New York, NY: Worth Publishers; Stuart, G.W. (2005). Principles and Practice of Psychiatric Nursing (9th ed.). St. Louis, MO: Mosby Elsevier; Ashton, C. H. (2002). The Ashton Manual. Newcastle Upon Tyne, UK: University of Newcastle.)
Disclaimer: The advice contained herein should not be substituted for the advice of a physician who is well-informed about your individual case. Before making any decisions about your health or treatment you should always confer with your physician.
