The benzodiazepine family of depressants is used therapeutically to produce sedation, induce sleep, relieve anxiety and muscle spasms, and to prevent seizures. In general, benzodiazepines act as hypnotics in high doses, anxiolytics in moderate doses, and sedatives in low doses.
Benzodiazepines are drugs of choice for various anxiety disorders and for insomnia.
Although there are 15 benzodiazepines are available, all have same actions and adverse actions and differ in only their onset of actions and duration of action.
Mechanism of action:
They act by binding to the gamma-aminobutyric acid (GABA) receptors- chloride channel molecule. These drugs intensify the effects of GABA, which is natural inhibitory neurotransmitter found throughout the brain.
They are metabolized in the liver to active metabolites and excreted by the kidneys. The main advantage of the drugs is that they do not produce the respiratory depression even in the high dose. Death is unlikely, unless they are taken in large quantities with other CNS depressants, or patients suffer with sleep apnea.
Uses and examples
They are mainly used as a:
- Seizures disorder ( including Absence and Myoclonic seizures)
- Alcohol withdrawal symptoms
- Central muscle relaxation
- Induction agents in general anesthesia
- Lorazepam has the advantage of promoting relaxation along with having antiemetic properties.
- Muscle relaxation action
- Decreased alertness and concentration
- Lack of coordination and impaired driving abilities
- Hypotension and respiratory inhibition with the use of IV drugs
- Nausea, vomiting, appetite change, blurred vision, confusion
- Euphoria, nightmares and liver toxicity