- Binds to benzodiazepine receptor sites on CNS cells. This promotes the interaction between gamma-aminobutyric acid (GABA) and its receptors on neurons. When GABA interacts with its receptor site, the neuron becomes permeable to chloride which is a negatively charged ion. An influx of chloride occurs making the inside of the cell more negative (hyperpolarized) and thus the cell takes longer to reach threshold and depolarize. This suppresses the spread of seizure activity by raising the seizure threshold.
- Skeletal muscle relaxation (for muscle spasm).
- Onset - 1 to 5 minutes
- Peak - 15 minutes
- Half-life - 20 to 50 hours
- Duration - 15 to 60 minutes
Note: All benzodiazepines are metabolized by the liver. Diazepam is converted by the cytochrome P450 enzymes in the liver to desmethyldiazepam (major) and oxazepam (minor). The fact that it has active metabolites makes it a longer lasting sedative than midazolam.
- Treatment of prolonged seizures (>5 min) or recurrent seizures.
- Sedation prior to electrical therapies (e.g. synchronized cardioversion, external cardiac pacing – use with caution in patients who are borderline unstable).
- Allergy or known hypersensitivity to benzodiazepines.
- Acute narrow-angle glaucoma (due to an anticholinergic effect).
- Myasthenia Gravis.
- Hypoglycemic seizures - be sure to check BGL in the seizing patient.
- May cause hypotension (Valium is mixed in propylene glycol, which is a vasodilator). Benzodiazepines also inhibit the neuronal re-uptake of Adenosine. The increase in circulating Adenosine outside the CNS may also explain why Diazepam has peripheral vasodilatory effects.
- May depress respirations (particularly in high dose: e.g. 10 mg in adults) - be prepared to assist ventilations.
- Impaired liver or kidney function.
- Patient who has ingested alcohol.
Drug to Drug interactions
- Increased risk of toxicity in patients taking cimetidine, disulfiram, oral contraceptives. Decreased effects of diazepam when given to patients taking theophyllines, ranitidine.
- 5 mg over 1 minute - repeat x1 prn for status seizures - secure airway prior to administering drug.
- 2 - 5 mg aliquots, given slow (over 1-2 minutes) for sedation - max. 30 mg.
- 0.2 mg/kg IV, PR or IO (max. 20 mg) is the standard dosage for pediatric patients.
- May precipitate when diluted with other solutions - DO NOT dilute/mix with any other solution.