Bromazepam

Introduction

Bromazepam is an intermediate-acting benzodiazepine. It is used in the short-term treatment of anxiety disorders, occuring alone or associated with insomnia.

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Bromazepam Tablet 1.5 mg	BROM01	DDA
Bromazepam Tablet 3 mg	BROM02	DDA

Mechanism of Action

• Bromazepam is a benzodiazepine.
• Gama-Aminobutyric acid (GABA) is an inhibitory neurotransmitter, acting on the GABA receptors in the central nervous system (CNS), thus inhibiting the nerve impulses.
• Bromazepam acts on the benzodiazepine receptors in the brain and the spinal cord. Benzodiazepine receptors in the CNS are linked with GABA receptors as a complex.
• Bromazepam by binding to the benzodiazepine receptors results in activation of the GABA-benzodiazepine receptor complex, resulting in inhibition of nerve impulses, overall depression of brain and spinal cord.
• Thus Bromazepam use helps to promote muscle relaxation, reduce anxiety, control of convulsions and promote sleep.

Dosage

Short-term use in anxiety	By mouth ADULT: 3 mg two or 3 times daily ELDERLY: Should not exceed 3 mg daily in divided doses DEBILITATED PATIENTS: should not exceed 3 mg daily in divided doses When the total dose is low (eg. 3 or 6 mg), to give the total dose in the evening

Side Effects

Sedative drugs, including alprazolam, have been associated with an increased risk of death.

Possible side effects include:

Very common (>10% of incidence) or Common (1-10% of incidence)	Amnesia and concentration problems Ataxia (especially in the elderly) Confusion (especially in the elderly) Drowsiness the next day Dizziness Muscle weakness Paradoxical increase in aggression
Infrequent (0.1 -1% of incidence)	Dysarthria Gastro-intestinal disturbances Gynecomastia headache Hypotension Incontinence Urinary retention, constipation Slurred speech Tremor Vertigo Visual disturbances
Rare (<0.1% of incidence)	Apnoea Blood disorder Jaundice Respiratory depression hypersensitivity reactions

Minor elevations of liver enzymes occurred in about 3% of patients.

Overdosage can produce CNS depression and coma.

Paradoxical reactions

Although unusual, the following paradoxical reactions have been shown to occur:

• aggression, rage
• mania, agitation, and restlessness
• hallucinations, inappropriate behavior
• twitches and tremor

Pharmacokinetics

Oral bioavailability	Bromazepam is well absorbed after oral doses.
Onset of action	Bromazepam is well absorbed after oral doses. Peak plasma concentrations are reached between 0.5 and 4 hours of a dose.
Metabolism	Bromazepam is metabolized in the liver
Elimination half-life	Bromazepam is eliminated in the urine. It has an elimination half-life of about 17 hours (range 11 – 22 hours).