Benzodiazepines
Cards (11)
- Examples:
- Diazepam
- Temazepam
- Lorazepam
- Chlordiazepoxide
- MOA:
- Increase affinity of GABA to bind to the GABA receptor
- This causes post-synaptic chloride ions channels to open
- GABA is an inhibitory neurotransmitter
- Route of delivery:
- PO
- IM
- IV - resuscitation facilities must be available
- Buccal
- Rectal
- Indications:
- Short-term treatment for severe, distressing or disabling anxiety
- Treatment of seizures and status epilepticus
- Short-term treatment for insomnia
- Alcohol withdrawal - chlordiazepoxide
- Tetanus, muscle spasm, acute drug-induced dystonia - diazepam
- Contraindications:
- Respiratory depression, respiratory failure and neuromuscular conditions e.g. unstable myasthenia gravis - benzodiazepines can cause loss of airway reflexes
- Cautions - avoid in liver failure due to risk of hepatic encephalopathy, consider lower doses in elderly patients (more susceptible to side effects)
- Interactions:
- CYP450 inhibitors - azoles (antifungals), some antibiotics, omeprazole, sodium valproate, grapefruit
- Alcohol and opioids - increased sedative effects
- Clozapine - increased CNS depression
- Anti-hypertensive mediation - increased hypotensive effects
- Common side effects:
- Amnesia, confusion, drowsiness
- Muscle weakness and ataxia
- Dependence
- Benzodiazepines are sometimes used for severely agitated patients but a rare side effect is rebound agitation
- Counselling:
- For short term use only - no more than 4 weeks and should not be taken every day
- Impairment of normal activities - driving, operating heavy machinery
- Withdrawal effects - very addictive and can cause withdrawal symptoms when stopped
- Stop alcohol consumption whilst on chlordiazepoxide
- Withdrawal of a benzodiazepine should be gradual because abrupt withdrawal may produce confusion, toxic psychosis, convulsions, or a condition resembling delirium tremens.
- Benzodiazepine withdrawal syndrome:
- Insomnia
- Anxiety
- Anorexia
- Tremor
- Perspiration
- Tinnitus
- Perceptual disturbances