Pentobarbital
Also known as: Nembutal, Dolethal, Euthanimal, Euthasal, Euthatal, Euthoxin, Lethobarb, Pentoject
This medication is a powerful sedative and anesthetic. * **Hospital Use:** It is almost exclusively used in a veterinary hospital setting under close professional supervision, often in an intensive care unit. * **At-Home Use:** If oral dosage forms are dispensed for home use, **strict adherence to the veterinarian's dosing instructions is critical**. Overdoses can be fatal. * **Safety:** Keep this medication in a secure, child-resistant container, completely out of reach of children and other pets. It is a strictly controlled substance.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- For chemical restraint for ventilatory support
- As a sedative
- As a sedative
- For status epilepticus
- For status epilepticus
- For anesthesia
- Euthanasia
- General
- As an anesthetic
- As an anesthetic
- As an anesthetic (Adult Sheep)
- As an anesthetic (Lambs)
- General anesthesia
- Light anesthesia
How it is given
Possible side effects
- Profound respiratory depression (apnea)
- Depression of myocardial metabolism
- Vasodilation and decreased venous return
- Hypotension and decreased cardiac perfusion
- Poikilothermia (hypothermia)
- Decreased urinary output
- Seizure-like movements or excitement during recovery from anesthesia
- Excitement and injury during induction/recovery in large animals (especially horses)
- Narcotic excitement (if not premedicated)
- Agonal gasping (reflexive, not a sign of pain)
- Muscle twitching
- Vocalization (rare, usually associated with excitement phase)
Cautions & contraindications
- Severe hepatic impairment
- Severe respiratory depression or airway obstruction
- Porphyria
- Hypovolemia or severe cardiovascular instability (relative contraindication)
- Intramuscular (IM) administration (painful and slow to act)
- Use of euthanasia-specific solutions for seizure control or anesthesia
- > **Cardiopulmonary Depression:** Pentobarbital causes dose-dependent respiratory and cardiovascular depression. Patients in a 'barbiturate coma' commonly require mechanical ventilation and intensive care support (e.g., saline infusion and dopamine to manage hypotension). > **Individual Variation:** There is tremendous individual variation in response when used at standard safe doses. Always titrate to effect. > **Laboratory Interference:** Barbiturates may cause increased retention of bromosulfophthalein (BSP) and give falsely elevated results. Do not administer within 24 hours before BSP retention tests. * **Equine Use:** Generally not considered an ideal agent for adult horses due to the possible development of excitement and injury when the animal is 'knocked down'. * **Tissue Irritation:** Highly alkaline (pH 9-10.5); perivascular injection can cause severe tissue necrosis.
Drug interactions
- Oral Anticoagulants (Warfarin): Decreased effect by lowering serum concentration (due to hepatic enzyme induction)
- Beta-blockers: Decreased effect by lowering serum concentration
- Chloramphenicol: Decreased effect by lowering serum concentration
- Clonazepam: Decreased effect by lowering serum concentration
- Corticosteroids: Decreased effect by lowering serum concentration
- Cyclosporine: Decreased effect by lowering serum concentration
- Doxorubicin: Decreased effect by lowering serum concentration
- Doxycycline: Decreased effect (may persist for weeks after barbiturate is discontinued)
- Estrogens: Decreased effect by lowering serum concentration
- Griseofulvin: Decreased effect by lowering serum concentration
- Methadone: Decreased effect by lowering serum concentration
Frequently asked questions
What is Pentobarbital used for in pets?
This medication is a powerful sedative and anesthetic. * **Hospital Use:** It is almost exclusively used in a veterinary hospital setting under close professional supervision, often in an intensive care unit. * **At-Home Use:** If oral dosage forms are dispensed for home use, **strict adherence to the veterinarian's dosing instructions is critical**. Overdoses can be fatal. * **Safety:** Keep this medication in a secure, child-resistant container, completely out of reach of children and other pets. It is a strictly controlled substance.
Is Pentobarbital safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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