Alprazolam

Indications

Alprazolam is used for: Anxiety disorders, Panic disorders, Nausea due to chemotherapy

Adult Dose

Oral Short-term management of anxiety Adult: 0.25-0.5 mg tid, increased to 3-4 mg daily if necessary. Elderly: Initially, 0.25 mg bid/tid. Panic attacks Adult Immediate-release 0.5 mg PO q8hr; may increase q3-4Days by ?1 mg/day Average dose: 5-6 mg/day PO May require up to 10 mg/day PO divided q8hr Extended-release 0.5-1 mg PO qDay; may increase q3-4Days by <1 mg/day Average dose: 3-6 mg PO qDay Anxiety Associated With Depression 1-4 mg/day PO divided q8hr Hepatic impairment: Avoid in severe impairment.

Child Dose

<18 years old: Not recommended

Renal Dose

Renal impairment: Use caution; not studied

Administration

Administration May be taken with or without food. Side effects eg sleepiness/drowsiness may be reduced if taken immediately after meals.

Contra Indications

Acute narrow-angle glaucoma, preexisting CNS depression or coma, resp depression, acute pulmonary insufficiency or sleep apnoea; severe hepatic impairment; pregnancy, lactation.

Precautions

Dosage reduction or gradual withdrawal. Dependence. Geriatric or debilitated patients. Muscle weakness, impaired hepatic or renal function; arteriosclerosis; obesity; depression particularly suicidal tendency; chronic pulmonary insufficiency. May impair ability to drive or operate machinery. Children <18 yr. Lactation: Enters breast milk/not recommended

Pregnancy-Lactation

Pregnancy category: D Lactation: Enters breast milk/not recommended Minor tranquilizers should be avoided in first trimester of pregnancy due to increased risk of congenital malformations Maternal use shortly before delivery is associated with floppy infant syndrome (good and consistent evidence) Prenatal benzodiazepine exposure slightly increases oral cleft risk (limited or inconsistent evidence)

Interactions

Potentiates action of alcohol and CNS depressants. Reduced conc with cigarette smoking by 50%. Potentially Fatal: Cimetidine and fluoxetine reduce the clearance of alprazolam. Alprazolam enhances activity of imipramine and desipramine.

Adverse Effects

Side effects of Alprazolam : >10% (4 mg dose) Drowsiness (41%), Depression (10-15%), Headache (10-15%), Constipation (10-15%), Diarrhea (10-15%), Dry mouth (10-15%) >10% (10 mg dose) Drowsiness (77%), Impaired coordination (40-50%), Increased appetite (30-35%), Fatigue (30-35%), Memory impairment (30-35%), Irritability (30-35%), Decreased salivation (30-35%), Cognitive disorders (20-30%), Insomnia (20-30%), Dcreased appetite (20-30%), Headache (20-30%), Lightheadedness (20-30%), Dysarthria (20-30%), Diarrhea, constipation, and nausea/vomiting (20-30%), Weight change (20-30%), Nasal congestion (15-20%), Decreased or increased libido (10-15%), Menstrual disorder (10-15%), Difficult micturition (10-15%) 1-10% (4 mg dose) Tachycardia (5-10%), Confusion (5-10%), Insomnia (5-10%), Nausea/vomiting (5-10%), Blurred vision (5-10%), Nasal congestion (5-10%), Hypotension (1-5%), Syncope (1-5%), Akathisia (1-5%), Dizziness (1-5%), Increased salivation (1-5%), Nervousness (1-5%), Tremor (1-5%), Weight change (1-5%) 1-10% (10 mg dose) Increased salivation (5-10%), Talkativeness (1-5%), Incontinence (1-5%) Potentially Fatal: Blood dyscrasias.

Mechanism of Action

Alprazolam binds to stereospecific benzodiazepine receptors on the postsynaptic GABA neuron at several sites w/in the CNS, including the limbic system, reticular formation. Enhancement of the inhibitory effect of GABA on neuronal excitability results by increased neuronal membrane permeability to Cl ions, which results in hyperpolarisation (a less excitable state) and stabilisation. Benzodiazepine receptors and effects appear to be linked to the GABA-A receptors.