Dosing and uses of Xanax, Niravam (alprazolam)
Adult dosage forms and strengths
tablet: Schedule IV
- 0.25mg
- 0.5mg
- 1mg
- 2mg
tablet, extended-release: Schedule IV
- 0.5mg
- 1mg
- 2mg
- 3mg
tablet, orally disintegrating: Schedule IV
- 0.25mg
- 0.5mg
- 1mg
- 2mg
oral solution: Schedule IV
- 1mg/mL
Anxiety
0.25-0.5 mg PO q6-8hr; titrate to effect q3-4Days; not to exceed 4 mg/day
Panic Disorder
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
Premenstrual Syndrome (Off-label)
0.25 mg PO q6-12hr; initiate treatment on day 16-18 of menses (not to exceed 3-4 mg/day); taper dose over 2-3 days once menses occurs
Dosing Modifications
Renal impairment
- Use caution; not studied
Advanced hepatic impairment
- Immediate-release: Decrease initial dose to 0.25 mg PO q8-12hr; may gradually increase if needed and as tolerated
- Extended-release: 0.5 mg PO qDay; may increase dose as needed and tolerated
Pediatric dosage forms and strengths
<18 years old: Not recommended
Geriatric dosage forms and strengths
Panic Disorder
Immediate-release: Decrease initial dose to 0.25 mg PO q8-12hr; may gradually increase if necessary and as tolerated; may increase every 3-4 days by ≤1 mg/day to 5-6 mg/day average dose
Extended-release: Start at 0.5 mg PO qDay; may gradually increase if necessary and as tolerated; may increase q3-4Days by ≤1 mg/day to 3-6 mg/day
Anxiety Associated With Depression
Decrease initial dose to 0.25 mg PO q8-12hr; may gradually increase if needed and as tolerated; may increase every 3-4 days by ≤ 1 mg/day to 1-4 mg/day
Maintenance: 1-4 mg/day PO divided q8hr
Dosing Considerations
Use smallest effective dose to avoid ataxia and oversedation
Elderly especially sensitive to benzodiazepine effects; higher plasma levels exhibited because of reduced clearance
Mean half-life: 16.3 hours in healthy elderly individuals (range: 9-26.9 hr), compared with 11 hours in healthy adults (range: 6.3-15.8 hr)
Xanax, Niravam (alprazolam) adverse (side) effects
>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%)
Postmarketing Reports
Gastrointestinal: Liver enzyme elevations, hepatitis, hepatic failure
CNS: Hypomania, mania
Immunologic: Stevens-Johnson syndrome, angioedema, peripheral edema
Endocrine: Hyperprolactinemia, gynecomastia, galactorrhea
Warnings
Contraindications
Documented hypersensitivity
Acute narrow angle glaucoma
Concomitant use with CYP3A4 inhibitors (itraconazole, ketoconazole)
Cautions
Anterograde amnesia reported with benzodiazepine use
Use with caution in patients with history of drug abuse or acute alcoholism; psychological dependence may occur with prolonged use (>10 days)
Do not stop treatment abruptly; slowly taper to discontinuation (0.5 mg q3Days)
Use caution in elderly patients
Use caution in debilitated patients
Use caution in severe respiratory depression
Use caution in patients who recently received other respiratory depressants
Use caution in patients who are at risk of falls
May have prolonged effects in obese patients when discontinued; use caution
Not for us in acute alcohol intoxication
Use with caution in patients with hepatic or renal impairment
Myasthenia gravis (allowable in limited circumstances)
Use caution in cases of respiratory disease (COPD), sleep apnea, renal/hepatic disease, open-angle glaucoma (questionable), depression, suicide ideation, drug abuse
CNS depressant; may impair ability to perform hazardous tasks
Paradoxical reactions, including hyperactive or aggressive behavior reported
Cigarette smoking may decrease alprazolam concentration up to 50%
Mania and hypomania episodes reported in depressed patients
Pregnancy and 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)
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Xanax, Niravam (alprazolam)
Mechanism of action
Binds receptors at several sites within the CNS, including the limbic system and reticular formation; effects may be mediated through GABA receptor system; increase in neuronal membrane permeability to chloride ions enhances the inhibitory effects of GABA; the shift in chloride ions causes hyperpolarization (less excitability) and stabilization of the neuronal membrane
Absorption
Bioavailability: 90%
Peak serum time: 1-2 hr (immediate release); 9 hr (extended release); 1.5-2 hr (disintegrating tablet)
Peak plasma concentration: 8-37 ng/mL (dose dependent)
Distribution
Protein bound: 80%
Vd: 0.9-1.2 L/kg
Metabolism
Metabolized by hepatic P-450 enzyme CYP3A4
Elimination
Half-life: 11 hr average for immediate release, 13 hr average for extended release, and 13 hr average for disintegrating tablets (adults); 16.3 hr (elderly); 21.8 hr (obesity)
Excretion: Urine
