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Diazepam in:
2mg tablet: Round, flat, bevel-edged, white tablet with a diameter of 7.94mm. It is scored on one side.
5mg tablet: Round, flat, bevel-edged, yellow tablet with a diameter of 7.94mm. It is scored on one side.
10mg tablet: Round, flat, bevel-edged, blue tablet with a diameter of 7.94mm. It is scored on one side.
Diazepam is a benzodiazepine tranquilliser that is believed to act by facilitating the synaptic actions of gamma aminobutyric acid (GABA). GABA is one of the major inhibitory neurotransmittors of the CNS. Diazepam does not act at the same site as GABA, but at a presumably allosterically-linked site, called the benzodiazepine receptor. It is through this site that the anticonvulsant, sedative, skeletal muscle relaxant and amnestic properties of diazepam are mediated.
Diazepam is readily and completely absorbed from the gastrointestinal tract. Peak plasma concentrations occur in 30-90 minutes after administration, but may be further delayed in elderly patients. Diazepam has a biphasic elimination curve, the terminal half-life being 1-2 days. It is extensively protein-bound.
Diazepam is metabolised in the liver and the following active metabolites are produced: desmethyldiazepam, methyloxazepam, oxazepam and temazepam. The metabolites are then eliminated by the kidneys in either their free or conjugated form. The half-life of diazepam is prolonged in patients with kidney or liver disease. Diazepam and its active metabolites show significant accumulation during multiple dosage regimens. Steady state plasma concentrations are attained in 5 days to 2 weeks, as some of its metabolites take several days to weeks to be eliminated.
Diazepam is used in the treatment of anxiety and tension states, as a sedative and in the control of skeletal muscle spasm.
Adults: As antianxiety, anticonvulsant and skeletal muscle relaxant, 2mg to 10mg two to four times a day. As a sedative-hypnotic and for alcohol withdrawal, 10mg three to four times a day for the first 24 hours, then decrease to 5mg three to four times a day as needed.
Children 6 Months of Age and Over: 1mg to 2.5mg (40mcg to 200mcg/kg body weight) three to four times a day, dosage being increased gradually as needed and tolerated.
Diazepam is not recommended for children less than 6 months of age.
Geriatric and Debilitated Patients: Usually half the adult dose. Start on 2mg to 2.5mg once or twice a day. Increase gradually as tolerated.
Diazepam should not be given to patients with acute closed-angle glaucoma, or a predisposition to it, myasthenia gravis, severe chronic obstructive pulmonary disease, hyperkinesis and children with swallowing abnormalities.
Diazepam should also be avoided in psychotic patients with mental illness or suicidal tendencies unless there is a marked component of anxiety. Also avoid use in patients with hypersensitivity to diazepam.
Diazepam is also contraindicated in acute alcohol intoxication with depressed vital signs and in patients with a history of drug abuse or dependence.
Diazepam may affect a patients ability to drive or operate machinery and may increase the effects of alcohol.
Avoid prolonged use since tolerance may develop and dependence of the barbiturate-alcohol type may occur.
Care must be exercised in elderly or debilitated patients, patients with impaired liver, kidney or respiratory function and in patients receiving other CNS depressant agents.
Care is needed when using in epileptic patients as abrupt withdrawal may provoke seizures.
Diazepam should be avoided in pregnancy as it is reported to increase the risk of congenital malformations and may also cause foetal intoxication. It should also be avoided when breast feeding as diazepam and its metabolites are excreted in breast milk. As neonates metabolise diazepam more slowly than adults, it accumulates and may cause sedation, possibly feeding difficulties and weight loss in the infant.
Abrupt withdrawal of diazepam may cause irritability, nervousness, and trouble sleeping in 10-20 days. Rarely does it cause confusion, abdominal cramps, convulsions, muscle cramps, nausea and vomiting, sweating and trembling.
These are usually mild and infrequent. Drowsiness, lightheadedness, clumsiness, unsteadiness and ataxia are the most common, especially in elderly and debilitated patients.
Less common are intolerance, mental depression, blurred vision or other vision changes, constipation, increased thirst, headache, increased bronchial secretions or watering mouth, nausea or vomiting, problems with urination, slurred speech and trembling.
Rarely does anaemia, yellow eyes or skin, muscle weakness, muscle spasm, neutropenia, paradoxical reactions such as hallucinations, trouble sleeping and unusual excitement, nervousness or irritability occur.
Diazepam interacts with all addictive medications, especially CNS depressants with habitual potential.
Diazepam with:
Alcohol or CNS Depressants: The dosage of one or both should be decreased. If diazepam is used with opioid analgesics, the dosage of the opioid analgesic should be decreased by at least one third.
Antacids: Concurrent use of these delays the absorption of diazepam.
Tricyclic Antidepressants: Concurrent use of these increases the CNS depressant effects.
Carbamazepine: Concurrent use results in an increase in hepatic metabolism, due to induction of hepatic microsomal enzyme activity leading to decreased serum concentrations and decreased elimination half-lives of diazepam.
Monitoring blood concentrations is recommended, especially if carbamazepine is added to or withdrawn from existing diazepam therapy.
Cimetidine, Estrogen-Containing Oral Contraceptives, Disulfiram and Erythromycin: Concurrent use of these inhibits hepatic metabolism (oxidation) of diazepam and therefore delays its elimination and increases diazepam plasma concentrations.
Isoniazid: Concurrent use may inhibit diazepam elimination.
Levodopa: Concurrent use may decrease the therapeutic effects of levodopa.
Rifampin: Enhances the elimination of diazepam, therefore, decreases plasma concentrations. Dosage adjustment necessary.
Zidovudine: Benzodiazepines competitively inhibit hepatic glucuronidation of zidovudine and therefore decrease its clearance which leads to toxicity. Avoid concurrent use.
Symptoms indicating need for medical attention include: continuing confusion and slurred speech, severe drowsiness, muscle weakness and decreased reflexes, staggering, slowed heartbeat and shortness of breath or troubled breathing.
Treatment includes inducing emesis if patient is conscious and the use of gastric lavage if patient is unconscious. Respiration, pulse and blood pressure should be monitored and oxygen administered if necessary. IV fluids may be used to promote diuresis. Hypotension may be controlled by vasopressors, dopamine, noradrenaline or metaraminol.
Store in a tight, light-resistant container below 30 degrees C preferably at room temperature (between 15-30 degrees C).
Controlled Drug C5
2mg, 5mg, 10mg: Bottles of 100.
Diazepam is designated chemically as 7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one. The chemical formula and molecular weight are C16H13ClN2O and 284.76 respectively.
Other ingredients of the tablets are:
Douglas Pharmaceuticals Ltd
P.O. Box 45-027
AUCKLAND 8
Ph: (09) 835-0660
Fax: (09) 835-0665
29 December 1998