Alprazolam
Also known as: Xanax XR · Niravam · Alprazolam Intensol · D65 MT · U 31889 · alprazolamum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For treatment of canine anxiety disorders | 0.01-0.1 mg/kg PO as needed for panic, not to exceed 4 mg/dog/day. Start with 1-2 mg (total dose) for a medium-sized dog. | PO | prn | — | 🌎 NA |
| For separation anxiety | 0.25 mg-2 mg (total dose) once daily to three times daily PO. | PO | q8-24h | — | 🌎 NA |
| For storm phobias | 0.02-0.4 mg/kg PO q4h as needed | PO | q4h | — | 🌎 NA |
| For storm phobias (adjunct) | 0.02 mg/kg PO as needed one hour before anticipated storm and every 4 hours as needed | PO | q4h | — | 🌎 NA |
| For phobias, night waking | 0.01-0.1 mg/kg or 0.25-2 mg (total dose) per dog PO q6-12h PO | PO | q6-12h | — | 🌎 NA |
| For acute anxiety | 0.05-0.1 mg/kg PO prn or three times a day. Administer 30-60 minutes prior to trigger event. | PO | prn or q8h | — | 🌎 NA |
| Anxiolysis and fear-related disorders | 0.01-0.1 mg/kg | PO | prn up to q6h | As needed | 🌍 EU |
- For storm phobias: Helps to minimize impact of experiencing a severe storm
- For storm phobias (adjunct): Used as an adjunct after behavior modification and prior clomipramine treatment
- Anxiolysis and fear-related disorders: Titrate up or down to the minimum effective dose. Best given ~30 mins before a fear-inducing event.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For treatment of feline anxiety disorders | 0.125-0.25 mg/kg PO q12h (Start at 0.125 mg/kg PO) | PO | q12h | — | 🌎 NA |
| For refractory house soiling | 0.1 mg/kg or 0.125-0.25 mg (total dose) per cat PO q8-12h | PO | q8-12h | — | 🌎 NA |
| For urine marking | 0.05-0.2 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
| For fears/phobias/anxieties | 0.125-0.25 mg (total dose) PO once to three times a day. | PO | q8-24h | — | 🌎 NA |
| For acute anxiety | 0.05 mg/kg PO prn or three times a day. Administer 30-60 minutes prior to trigger event. | PO | prn or q8h | — | 🌎 NA |
| Anxiolysis and urine spraying | 0.125-0.25 mg/kg | PO | prn up to bid | As needed | 🌍 EU |
- Anxiolysis and urine spraying: Doses as low as 0.25 mg/cat q8-12h and as high as 0.6 mg/kg have been reported. Titrate down to minimum effective dose. High relapse rate for urine spraying upon withdrawal.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Alprazolam is a potent, short-to-intermediate-acting benzodiazepine primarily used in veterinary medicine as an anxiolytic and mild sedative. It is a Schedule IV (C-IV) controlled substance.
Key clinical highlights include:
- Behavioral Modification: Frequently prescribed as an adjunctive therapy for panic disorders, storm phobias, separation anxiety, and inappropriate elimination (e.g., feline urine marking).
- Motor Function: Compared to diazepam, alprazolam may have less negative impact on motor function at lower doses, making it favorable for ambulatory patients.
- Clinical Pearl: Because it is highly lipid-soluble, it has a rapid onset when given orally, making it ideal for situational anxieties (e.g., thunderstorms, fireworks) if administered 30-60 minutes prior to the trigger event.
Mechanism of action
Alprazolam exerts its effects by binding to specific benzodiazepine receptors located on the GABA-A receptor complex in the central nervous system.
- Mechanism: Binding → enhances the affinity of the receptor for gamma-aminobutyric acid (GABA) → increases the frequency of chloride channel opening → cellular hyperpolarization → decreased neuronal excitability.
- Target Areas: It primarily depresses subcortical levels of the CNS, specifically the limbic system, thalamus, and hypothalamus.
- Net Effect: This enhanced inhibitory neurotransmission produces the characteristic anxiolytic, sedative, skeletal muscle relaxant, and anticonvulsant effects.
Safety & warnings
Contraindications
- Known benzodiazepine hypersensitivity
- Aggressive animals (controversial; anxiety reduction may disinhibit aggressive tendencies)
Adverse effects
- Sedation
- Increased appetite (polyphagia)
- Transient ataxia
- Behavior changes in cats (irritability, increased affection, depression, aberrant demeanor)
- Paradoxical CNS excitement/agitation (rare in dogs)
- Physical dependence (with chronic use)
- Impeded learning and retarded training
Precautions
Caution: Use with care in patients with hepatic or renal disease, narrow-angle glaucoma, and in debilitated or geriatric patients.
- Working Animals: Benzodiazepines may impair the abilities of working or service animals.
- Aggression: Use in aggressive dogs remains controversial as it may remove anxiety-based bite inhibition.
- Pregnancy: FDA Category D in humans. May cause congenital abnormalities if administered during the first trimester. Use only when benefits clearly outweigh risks.
- Hepatic Function: Monitor hepatic enzymes, particularly in cats receiving chronic therapy, due to the risk of idiosyncratic hepatotoxicity associated with some oral benzodiazepines.
Drug interactions
May slow the rate, but not the extent of oral absorption of alprazolam; administer 2 hours apart.
Additive CNS depression effects may occur.
Serum levels of digoxin may be increased; monitor for toxicity.
Increased alprazolam levels.
Metabolism of alprazolam may be decreased, leading to excessive sedation.
May induce hepatic microsomal enzymes and decrease the pharmacologic effects of benzodiazepines.
Alprazolam may increase levels of these drugs; concurrent use with clomipramine may improve efficacy for phobias.
Inhibits alprazolam metabolism, potentially increasing sedation and toxicity
Inhibits alprazolam metabolism
Used concurrently as an adjunct, but may have additive CNS depressant effects
Monitoring
- Clinical efficacy (reduction in anxiety/panic)
- Adverse effects (excessive sedation, paradoxical excitation)
- Hepatic enzymes (particularly when treating cats chronically)
Pharmacokinetics
Absorption
Well absorbed orally with an intermediate onset of action. Peak plasma levels occur in 1-2 hours (in humans).
Distribution
Highly lipid soluble and widely distributed throughout the body. Readily crosses the blood-brain barrier. Approximately 80% bound to plasma proteins.
Metabolism
Metabolized in the liver to at least two metabolites, including alpha-hydroxy-alprazolam which is pharmacologically active.
Elimination
Elimination half-lives range from 6-27 hours in humans.
Overdose
Overdoses are generally limited to CNS signs, primarily dose-dependent CNS depression.
- Clinical Signs: Ataxia, lethargy, disorientation, and vomiting. Some animals may present with a paradoxical reaction (hyperactivity, vocalization, agitation) which may be followed by CNS depression. Severe signs like hypotension, respiratory depression, and cardiac arrest are quite rare in small animals.
- Toxicity: The reported LD50 in rats is >330 mg/kg, but cardiac arrest has occurred at doses as low as 195 mg/kg.
- Treatment: Consists of standard protocols for decontamination. The decision to give activated charcoal should be weighed carefully against the risk of aspiration if the patient is sedated. Flumazenil can be used to reverse the sedative effects, but is generally reserved for cases with significant CNS and respiratory depression.
Available products
Formulations
- Extended-release oral tablets
- Orally disintegrating tablets
- Oral solution
Human-labeled
- Alprazolam Oral Tablets: 0.25 mg, 0.5 mg, 1 mg & 2 mg (Xanax, generic)
- Alprazolam Extended-release Oral Tablets: 0.5 mg, 1 mg, 2 mg, & 3 mg (Xanax XR, generic)
- Alprazolam Orally Disintegrating Tablets: 0.25 mg, 0.5 mg, 1 mg, & 2 mg (Niravam)
- Alprazolam Oral Solution: 1 mg/mL in 30 mL (Alprazolam Intensol)
Regulatory status
POM (Prescription Only Medicine). Subject to controlled drug regulations depending on member state.
POM. Controlled drug.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store tablets at room temperature in tight, light-resistant containers. Orally disintegrating tablets must be protected from moisture. Compounded oral suspensions (1 mg/mL in Ora-Plus/Ora-Sweet) retain >90% potency for 60 days at 5°C and 25°C, but should be protected from light.
Client information
- Timing is crucial: For situational anxiety (like thunderstorms or fireworks), give the medication approximately 30 to 60 minutes before the anticipated event to ensure it takes effect before the pet becomes panicked.
- Administration: If you have difficulty pilling your pet, orally disintegrating tablets may be an option. Ensure your hands are completely dry before handling them.
- What to watch for: Contact your veterinarian if you notice excessive sleepiness, severe unsteadiness, or any yellowing of the whites of the eyes or gums (jaundice), especially in cats.
- Behavioral changes: Some pets may become unusually affectionate, irritable, or even more active (paradoxical reaction). Let your vet know if this occurs.
- Training: This medication may temporarily slow your pet's ability to learn new commands during training sessions.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.