Diazepam

A benzodiazepine with anticonvulsant, anxiolytic, sedative, muscle relaxant, and amnesic properties and a long duration of action. Its actions are mediated by enhancement of gamma-aminobutyric acid activity. It is used in the treatment of severe anxiety disorders, as a hypnotic in the short-term management of insomnia, as a sedative and premedicant, as an anticonvulsant, and in the management of alcohol withdrawal syndrome. (From Martindale, The Extra Pharmacopoeia, 30th ed, p589)

Given diazepam's storied history as a commonly used and effective medication for a variety of indications, contemporary advancements in the formulation and administration of the agent include the development. Combining diazepam, a proven effective therapy for acute repetitive seizures, with an auto-injector designed for subcutaneous administration that is quickly and easily administered offers the potential for complete, consistent drug absorption and rapid onset of effect . This current development is subsequently an important addition to the rescue therapy tool chest for patients with epilepsy .

Diazepam is a long-acting benzodiazepine with rapid onset commonly used to treat panic disorders, severe anxiety, alcohol withdrawal, and seizures.

In general, diazepam is useful in the symptomatic management of mild to moderate degrees of anxiety in conditions dominated by tension, excitation, agitation, fear, or aggressiveness such as may occur in psychoneurosis, anxiety reactions due to stress conditions, and anxiety states with somatic expression.

Moreover, in acute alcoholic withdrawal, diazepam may be useful in the symptomatic relief of acute agitation, tremor, and impending acute delirium tremens.

Furthermore, diazepam is a useful adjunct for the relief of skeletal muscle spasm due to reflex spasm to local pathologies, such as inflammation of the muscle and joints or secondary to trauma; spasticity caused by upper motor neuron disorders, such as cerebral palsy and paraplegia; athetosis and the rare "stiff man syndrome".

Particular label information from the United Kingdom also lists particular age-specific indications, including for adults: (1) The short-term relief (2-4 weeks) only, of anxiety which is severe, disabling, or subjecting the individual to unacceptable distress, occurring alone or in association with insomnia or short-term psychosomatic, organic or psychotic illness, (2) cerebral palsy, (3) muscle spasm, (4) as an adjunct to certain types of epilepsy (eg. myoclonus), (5) symptomatic treatment of acute alcohol withdrawal, (6) as oral premedication for the nervous dental patient, and (7) for premedication before surgery.

In the same UK label information, diazepam is indicated in children for: (1) control of tension and irritability in cerebral spasticity in selected cases, (2) as an adjunct to the control of muscle spasm in tetanus, and for (3) oral premedication.

A diazepam nasal spray is indicated in patients 6 years and older to treat intermittent, stereotypic episodes of frequent seizure activity that are different than the patient's usual seizure pattern.

• Alcohol Withdrawal Syndrome
• Anxiety
• Anxiety Disorders
• Refractory Epilepsy
• Intermittent distinct from a patient’s usual seizure pattern
• stereotypic episode Epileptic seizure
• Refractory seizure disorders
• Skeletal muscle spasm
• Sedation
• Perioperative management therapy

Diazepam is a benzodiazepine that exerts anxiolytic, sedative, muscle- relaxant, anticonvulsant and amnestic effects . Most of these effects are thought to result from facilitation of the action of gamma aminobutyric acid (GABA), an inhibitory neurotransmitter in the central nervous system .

Diazepam is a benzodiazepine tranquilliser with anticonvulsant, sedative, muscle relaxant and amnesic properties .

Benzodiazepines, such as diazepam, bind to receptors in various regions of the brain and spinal cord. This binding increases the inhibitory effects of gamma-aminobutyric acid (GABA) . GABAs functions include CNS involvement in sleep induction. Also involved in the control of hypnosis, memory, anxiety, epilepsy and neuronal excitability .

After oral administration, it is considered that diazepam is rapidly and completely absorbed from the gastrointestinal tract as >90% of diazepam is absorbed and the average time to achieve peak plasma concentrations is 1 – 1.5 hours with a range of 0.25 to 2.5 hours .

Absorption is delayed and decreased when administered with a moderate fat meal . In the presence of food mean lag times are approximately 45 minutes as compared with 15 minutes when fasting . There is also an increase in the average time to achieve peak concentrations to about 2.5 hours in the presence of food as compared with 1.25 hours when fasting . This results in an average decrease in Cmax of 20% in addition to a 27% decrease in AUC (range 15% to 50%) when administered with food .

In young healthy males, the volume of distribution at steady-state is 0.8 to 1.0 L/kg .

Despite high binding to plasma proteins (98-99%) - mainly albumin and to a lesser extent α1-acid glycoprotein - diazepam is widely distributed into tissues and crosses the blood-brain barrier and is highly lipid soluble, which causes the initial effects to decrease rapidly as it is redistributed into fat deposits and tissues .

Diazepam and its metabolites are excreted mainly in the urine, predominantly as their glucuronide conjugates .

Diazepam has a biphasic half-life with an initial rapid distribution phase followed by a prolonged terminal elimination phase of 1 or 2 days; its action is further prolonged by the even longer half-life of 2-5 days of its principal active metabolite, desmethyldiazepam (nordiazepam), the relative proportion of which increases in the body on long-term administration . The plasma half-life of diazepam is prolonged in neonates, in the elderly, and in patients with kidney or liver disease .

The clearance of diazepam is 20 to 30 mL/min in young adults .

The symptoms of diazepam overdose are mainly an intensification of the therapeutic effects (ataxia, drowsiness, dysarthria, sedation, muscle weakness, profound sleep, hypotension, bradycardia, nystagmus) or paradoxical excitation . In most cases only observation of vital functions is required .

Extreme overdosage may lead to coma, areflexia, cardio-respiratory depression and apnoea, requiring appropriate countermeasures (ventilation, cardiovascular support) .

Benzodiazepine respiratory depressant effects are more serious in patients with severe chronic obstructive airways disease . Severe effects in overdose also include rhabdomyolysis and hypothermia . Overdose of benzodiazepines in combination with other CNS depressants (including alcohol) may be fatal and should be closely monitored .

In general, the use of diazepam in women of childbearing potential, and more specifically during known pregnancy, should be considered only when the clinical situation warrants the risk to the fetus . The possibility that a woman of childbearing potential may be pregnant at the time of institution of therapy should be considered . If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus . Patients should also be advised that if they become pregnant during therapy or intend to become pregnant they should communicate with their physician about the desirability of discontinuing the drug .

Special care must be taken when diazepam is used during labor and delivery, as high single doses may produce irregularities in the fetal heart rate and hypotonia, poor sucking, hypothermia, and moderate respiratory depression in the neonates . With newborn infants it must be remembered that the enzyme system involved in the breakdown of the drug is not yet fully developed (especially in premature infants) .

Diazepam passes into breast milk . Breastfeeding is therefore not recommended in patients receiving diazepam .

Safety and effectiveness in pediatric patients below the age of 6 months have not been established .

In elderly patients, it is recommended that the dosage be limited to the smallest effective amount to preclude the development of ataxia or oversedation (2 mg to 2.5 mg once or twice daily, initially to be increased gradually as needed and tolerated) . Extensive accumulation of diazepam and its major metabolite, desmethyldiazepam, has been noted following chronic administration of diazepam in healthy elderly male subjects. Metabolites of this drug are known to be substantially excreted by the kidney, and the risk of toxic reactions may be greater in patients with impaired renal function . Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function .

Decreases in clearance and protein binding, and increases in volume of distribution and half-life has been reported in patients with cirrhosis . In such patients, a 2- to 5- fold increase in mean half-life has been reported . Delayed elimination has also been reported for the active metabolite desmethyldiazepam . Benzodiazepines are commonly implicated in hepatic encephalopathy . Increases in half-life have also been reported in hepatic fibrosis and in both acute and chronic hepatitis .

• Avoid alcohol.
• Take on an empty stomach. Food may decrease absorption and time to therapeutic effect.

• Anxiety: 2 mg thrice daily, increased if necessary to 15-30 mg daily in divided doses. Elderly (or debilitated), half of the adult dose.
• Insomnia associated with anxiety: 5-15 mg at bedtime.
• Night terrors and somnambulism in Child: 1-5 mg at bedtime.

• For severe acute anxiety, control of acute panic attacks, and acute alcohol withdrawal: 10 mg repeated if necessary after not less than 4 hours.
• Febrile convulsion in children: Slow IV in a dose of 250 mcg/kg.

• In case of children- A dose of 500 mcg/kg (maximum 10 mg), repeated if necessary.