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Prazosin

Prescription
Alpha-1 adrenergic blocker (selective)
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
3 available
Interactions
1 documented
Formulations
3

Mechanism of action

Selectively blocks alpha-1 adrenergic receptors, relaxing urethral and prostatic smooth muscle; also reduces systemic vascular resistance

At a glance

Class
Alpha-1 adrenergic blocker (selective)
Schedule
Prescription
Storage
Store below 25°C, protect from light

Dosing

🐕

Dog

Urethral sphincter hypertonus / Functional urinary retention
Dose
0.5–2 mg per dog
Route
PO
Frequency
BID to TID
Max dose
5 mg/dose; 15 mg/day
Duration: As needed
🐈

Cat

Feline urethral obstruction (post-unblocking) / FLUTD
Dose
0.25–0.5 mg per cat
Route
PO
Frequency
BID to TID
Max dose
1 mg/dose; 3 mg/day
Duration: 5–14 days post-catheter removal
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Tablet — 2

Strength
1mg
Available in India
Strength
2mg
Available in India
💊

Capsule — 1

Strength
1mg
Available in India

Storage

Store below 25°C, protect from light

Safety

Absolute contraindications — do not use

  • Hypotension

Use with caution

  • Renal impairment

Adverse effects

Common
Hypotension (first-dose effect)
Lethargy
Serious
Syncope
Severe hypotension

Monitoring parameters

Blood pressureUrination frequency/volume
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Interactions

Moderate — 1

Amlodipine
moderate
Additive hypotensive effect — both are vasodilators acting through different mechanisms
Management: Start prazosin at lowest dose if patient is on amlodipine. Monitor blood pressure closely.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Brands

International

Minipress
Pfizer

India

Prazopress
Sun Pharma
Prazocip
Cipla

FAQs

Frequently asked questions

What is Prazosin?
Prazosin is a alpha-1 adrenergic blocker (selective) used in pets. Selectively blocks alpha-1 adrenergic receptors, relaxing urethral and prostatic smooth muscle; also reduces systemic vascular resistance
What is Prazosin used for in pets?
Prazosin is used in veterinary medicine for: Urethral sphincter hypertonus / Functional urinary retention; Feline urethral obstruction (post-unblocking) / FLUTD.
What is the Prazosin dose for dogs?
For dogs, Prazosin is typically dosed as follows — Urethral sphincter hypertonus / Functional urinary retention: 0.5–2 mg per dog PO BID to TID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Prazosin dose for cats?
For cats, Prazosin is typically dosed as follows — Feline urethral obstruction (post-unblocking) / FLUTD: 0.25–0.5 mg per cat PO BID to TID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What are the side effects of Prazosin?
Common: Hypotension (first-dose effect), Lethargy. Serious (call your vet immediately): Syncope, Severe hypotension.
Does Prazosin need a prescription?
Yes. Prazosin is a prescription medication and should only be administered under veterinary supervision.
When should Prazosin not be used?
Do not use Prazosin if: Hypotension.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

References

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

  • Plumb's Veterinary Drug Handbook
  • Withrow & MacEwen's Small Animal Clinical Oncology
  • Merck Veterinary Manual
  • NRC Nutrient Requirements of Dogs and Cats
  • Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

  • ASPCA Animal Poison Control Center Guidelines
  • AAHA Diabetes Management Guidelines
  • ASPCA Poison Control Guidelines
  • RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

  • EPIC Study (J Vet Intern Med 2016)
  • JVIM FAT CAT Study

Regulatory & approvals — 1

  • CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

  • Washington State University VCPL MDR1 Database
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