1. Clinical Overview
Chlordiazepoxide is a long-acting benzodiazepine derivative, primarily used as an anxiolytic, sedative, and for alcohol withdrawal management. It acts as a positive allosteric modulator at the GABA-A receptor, enhancing inhibitory neurotransmission in the CNS. It is one of the earliest benzodiazepines developed and remains in use, though newer agents are often preferred due to its long half-life and active metabolites.
| Onset | Duration | Bioavailability |
|---|---|---|
| Oral: 30 to 60 minutes. | Approximately 24 to 48 hours, due to long half-life and active metabolites. | Approximately 90-100% following oral administration. |
2. Mechanism of Action
Chlordiazepoxide binds to a specific site (the benzodiazepine site) on the GABA-A receptor, a ligand-gated chloride ion channel. This binding increases the frequency of chloride channel opening in response to GABA, enhancing the inhibitory effect of GABA. This leads to hyperpolarization of the neuronal membrane and reduced neuronal excitability throughout the central nervous system.
3. Indications & Uses
- Management of anxiety disorders (generalized anxiety disorder, panic disorder)
- Short-term relief of anxiety symptoms
- Acute alcohol withdrawal syndrome (to manage agitation, tremor, impending delirium tremens)
4. Dosage & Administration
Adult Dosage: Anxiety: 15-40 mg daily in 3-4 divided doses. Usual starting dose is 5-10 mg TID/QID. Alcohol Withdrawal: 50-100 mg initially, repeated as needed up to 300 mg/day, then tapered.
Administration: Administer orally with or without food. Tablets should be swallowed whole with a glass of water. For anxiety, doses are typically divided. For insomnia due to anxiety, a single dose at bedtime may be used. Do not crush or chew unless specified (some brands may be scored).
5. Side Effects
Common side effects may include:
- Drowsiness, sedation
- Dizziness, lightheadedness
- Unsteadiness, ataxia (impaired coordination)
- Fatigue, lethargy
- Dry mouth, constipation
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Alcohol | Profound additive CNS depression, respiratory depression, impaired psychomotor function. | Major |
| Opioids (e.g., Codeine, Tramadol) | Increased risk of profound sedation, respiratory depression, coma, and death. | Major (Black Box Warning for combination use) |
| Other CNS Depressants (Antipsychotics, Antihistamines, Barbiturates) | Additive CNS depression. | Major |
| CYP3A4 Inhibitors (e.g., Ketoconazole, Clarithromycin, Ritonavir) | Increased chlordiazepoxide levels, risk of toxicity. | Moderate |
| CYP3A4 Inducers (e.g., Rifampicin, Carbamazepine, Phenytoin) | Decreased chlordiazepoxide levels, reduced efficacy. | Moderate |
| Probenecid | May delay onset and increase duration of action. | Moderate |
| Oral Contraceptives | May inhibit metabolism, increasing chlordiazepoxide levels. | Minor |
| Theophylline | May antagonize sedative effects of benzodiazepines. | Minor |
7. Patient Counselling
- DO take exactly as prescribed by your doctor.
- DO NOT increase the dose or frequency without consulting your doctor.
- DO NOT stop taking this medicine suddenly after long-term use; it must be tapered slowly under medical supervision to avoid withdrawal seizures.
- DO NOT consume alcohol or products containing alcohol while on this medication.
- DO inform all your doctors and dentists that you are taking this medicine.
- DO keep all appointments for follow-up to assess the need for continued therapy.
8. Toxicology & Storage
Overdose: Manifestations range from CNS depression (drowsiness, confusion, lethargy, ataxia) to coma, diminished reflexes, respiratory depression, apnea, hypotension, and cardiovascular collapse. Death is rare when taken alone but common with co-ingestion of alcohol or other CNS depressants.
Storage: Store at room temperature (15-30°C), protected from light and moisture. Keep in the original container, tightly closed. Keep out of reach of children and pets. Do not flush unused medication. Dispose of unused tablets through a pharmacy take-back program or as per local regulations.