Propofol — Veterinary Vademecum Drug Reference

Dosage & Administration Guidelines

Species	Route	Dose	Frequency	Duration & Clinical Notes
Dog	IV	Induction: 4-6 mg/kg (slowly to effect); Maintenance: 0.1-0.4 mg/kg/min (CRI)	Induction: single bolus; Maintenance: continuous rate infusion	Duration: As needed for procedure Notes: Dose may be reduced with premedication (e.g., opioids, alpha-2 agonists). Administer slowly to avoid apnea and hypotension.
Cat	IV	Induction: 6-8 mg/kg (slowly to effect); Maintenance: 0.1-0.3 mg/kg/min (CRI)	Induction: single bolus; Maintenance: continuous rate infusion	Duration: As needed for procedure Notes: Cats may require higher doses due to rapid metabolism. Premedication reduces dose requirements.
Horse	IV	Induction: 2-4 mg/kg; Maintenance: 0.1-0.2 mg/kg/min (CRI)	Induction: single bolus; Maintenance: continuous rate infusion	Duration: As needed for procedure Notes: Often used in combination with other agents (e.g., ketamine, alpha-2 agonists) for TIVA. Monitor cardiovascular and respiratory function closely.
Cattle	IV	Induction: 2-4 mg/kg; Maintenance: 0.1-0.2 mg/kg/min (CRI)	Induction: single bolus; Maintenance: continuous rate infusion	Duration: As needed for procedure Notes: Use with caution in ruminants due to risk of regurgitation and bloat. Premedication with anticholinergics may be considered.
Small Ruminants (sheep, goats)	IV	Induction: 4-6 mg/kg; Maintenance: 0.1-0.3 mg/kg/min (CRI)	Induction: single bolus; Maintenance: continuous rate infusion	Duration: As needed for procedure Notes: Similar to cattle, monitor for regurgitation. Dose may vary based on species and individual response.
Rabbit	IV	Induction: 5-10 mg/kg (slowly to effect); Maintenance: 0.2-0.5 mg/kg/min (CRI)	Induction: single bolus; Maintenance: continuous rate infusion	Duration: As needed for procedure Notes: Rabbits are sensitive to respiratory depression; use with assisted ventilation if needed.
Birds/Poultry	IV	Induction: 5-10 mg/kg (slowly to effect); Maintenance: 0.2-0.5 mg/kg/min (CRI)	Induction: single bolus; Maintenance: continuous rate infusion	Duration: As needed for procedure Notes: Dose varies widely among species. Use with caution in debilitated birds.
Exotic/Other (e.g., reptiles, small mammals)	IV	Variable; often 5-10 mg/kg for induction	Induction: single bolus; Maintenance: as needed	Duration: As needed for procedure Notes: Limited data; use with caution and monitor closely.

Clinical Indications & Species Uses

General Indications

Induction and maintenance of general anesthesia
Sedation for diagnostic or minor surgical procedures
Total intravenous anesthesia (TIVA) in combination with analgesics

Dog (Canine)

Induction and maintenance of general anesthesia
Sedation for short procedures
Adjunct to balanced anesthesia

Cat (Feline)

Induction and maintenance of general anesthesia
Sedation for short procedures
Adjunct to balanced anesthesia

Horse (Equine)

Induction of general anesthesia
Maintenance of anesthesia (as part of total intravenous anesthesia, TIVA)

Cattle (Bovine)

Induction of general anesthesia
Sedation for short procedures

Small Ruminants (Sheep / Goat)

Induction of general anesthesia
Sedation for short procedures

Rabbit & Small Mammals

Induction and maintenance of general anesthesia
Sedation for short procedures

Avian & Poultry

Induction of general anesthesia
Sedation for short procedures

Exotic & Other Species

Induction and maintenance of anesthesia in various exotic species (e.g., reptiles, small mammals)

Pharmacology & Mechanism of Action

Drug Class: Anesthetic | Pharmacological Group: Hypnotic / General Anesthetic

Mechanism of Action: Propofol is a short-acting intravenous anesthetic agent that produces hypnosis and anesthesia by potentiating the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) at GABA-A receptors. It increases the duration of chloride channel opening, leading to hyperpolarization of neurons and inhibition of neuronal firing. This results in rapid loss of consciousness and depression of the central nervous system. It also has minor effects on other receptors, including glycine and nicotinic acetylcholine receptors, contributing to its anesthetic and muscle relaxant properties.

Pharmacodynamics: Propofol produces dose-dependent sedation, hypnosis, and anesthesia. It has a rapid onset of action (within 30-60 seconds) and a short duration of effect (5-10 minutes) due to rapid redistribution and metabolism. It causes a decrease in cerebral blood flow, intracranial pressure, and cerebral metabolic rate, making it useful in neuroanesthesia. It also has antiemetic properties and may cause a reduction in arterial blood pressure due to vasodilation and mild myocardial depression. Respiratory depression is common, especially with rapid bolus administration.

⚡ Pharmacokinetics Summary

Absorption: Propofol is administered intravenously; absorption is not applicable. It is not absorbed orally due to extensive first-pass metabolism.

Distribution: Propofol is highly lipophilic and rapidly distributes from blood to highly perfused tissues (brain, liver, kidneys) and then to muscle and fat. The volume of distribution is large (2-10 L/kg in dogs and cats). It crosses the blood-brain barrier rapidly, accounting for its quick onset of action.

Metabolism: Propofol is extensively metabolized in the liver by conjugation to glucuronide and sulfate metabolites, and to a lesser extent by oxidation to 2,6-diisopropyl-1,4-quinol. The metabolites are inactive. Hepatic clearance is high, but extrahepatic metabolism (e.g., in the lungs and kidneys) may also occur.

Excretion: Metabolites are excreted primarily in the urine (about 88%) and to a small extent in feces. Less than 2% of the drug is excreted unchanged. The elimination half-life is short (approximately 1-2 hours in dogs and cats) but may be prolonged with prolonged infusion due to redistribution from fat stores.

Half-Life: Dogs: 1-2 hours; Cats: 1-2 hours; Horses: 30-60 minutes; Cattle: 30-60 minutes; Rabbits: 30-60 minutes; Birds: 30-60 minutes (approximate).

Bioavailability: Not applicable for IV administration. Oral bioavailability is negligible due to first-pass metabolism.

Protein Binding: Propofol is highly protein-bound (97-99%) in most species, primarily to albumin.

Available Formulations & Strengths

Injectable Emulsion 10 mg/mL (1%) (IV)

Injectable Emulsion 20 mg/mL (2%) (IV)

Contraindications & Clinical Warnings

Contraindications:

Hypersensitivity to propofol or any component of the formulation (including soybean oil, egg lecithin, or glycerol)
Patients with known lipid metabolism disorders (e.g., hyperlipidemia, pancreatitis)
Patients with severe cardiovascular instability (e.g., hypovolemia, shock)
Patients with respiratory insufficiency or respiratory depression
Use in pregnant animals unless benefits outweigh risks (safety not established)

Warnings & Clinical Precautions:

Administer only by slow IV injection to minimize apnea and hypotension.
Monitor respiratory rate, heart rate, blood pressure, and oxygen saturation continuously during use.
Use with caution in patients with hepatic or renal impairment, as metabolism may be reduced.
Propofol emulsion supports bacterial growth; use aseptic technique and discard any unused portion after 6 hours.
In dogs and cats, propofol may cause transient apnea, especially with rapid administration.
In horses, propofol may cause excitement during recovery; use with appropriate premedication.
In ruminants, risk of regurgitation and aspiration; consider fasting and use of anticholinergics.
May cause pain on injection; consider adding lidocaine or using a larger vein.
Prolonged infusion may lead to propofol infusion syndrome (rare but serious) characterized by metabolic acidosis, rhabdomyolysis, and cardiac arrhythmias.
Use with caution in neonates and geriatric patients, as dose requirements may be reduced.

Adverse Effects & Reactions

Common:

Apnea
Hypotension
Pain on injection
Transient excitement during induction or recovery
Respiratory depression
Muscle twitching or myoclonus

Serious / Severe:

Cardiovascular collapse
Severe respiratory depression or apnea
Propofol infusion syndrome (with prolonged use)
Anaphylaxis (rare)
Pulmonary edema (rare)
Seizures (rare)

Rare:

Hyperlipidemia
Pancreatitis
Metabolic acidosis
Rhabdomyolysis
Cardiac arrhythmias
Injection site reactions (thrombophlebitis)

Key Drug Interactions

Interacting Drug / Class	Clinical Effect & Mechanism	Severity
Opioids (e.g., fentanyl, morphine)	Additive respiratory depression and sedation; may enhance anesthetic effects.	Moderate
Benzodiazepines (e.g., diazepam, midazolam)	Additive sedation and respiratory depression; may reduce propofol dose requirements.	Moderate
Alpha-2 agonists (e.g., xylazine, dexmedetomidine)	Enhanced sedation, bradycardia, and hypotension; reduce propofol dose.	High
Inhalant anesthetics (e.g., isoflurane, sevoflurane)	Additive cardiovascular and respiratory depression; may reduce MAC of inhalants.	Moderate
Neuromuscular blocking agents (e.g., atracurium)	May enhance neuromuscular blockade; monitor closely.	Mild
Ketamine	May cause additive cardiovascular effects; combination may be used for balanced anesthesia.	Moderate
Anticholinergics (e.g., atropine)	May counteract bradycardia but not hypotension.	Mild

Overdose & Toxicity Management

Signs of Toxicity:

Severe respiratory depression or apnea
Hypotension
Bradycardia
Cardiovascular collapse
Loss of consciousness
Muscle twitching or seizures (rare)

Emergency Treatment Protocol: Treatment is primarily supportive. Maintain airway and provide assisted ventilation (oxygen supplementation, intubation, mechanical ventilation if needed). Administer intravenous fluids to support blood pressure. Use vasopressors (e.g., dopamine, norepinephrine) if hypotension persists. Monitor cardiac function and treat arrhythmias if they occur. In cases of propofol infusion syndrome, discontinue propofol immediately and provide metabolic support (e.g., bicarbonate for acidosis, treat hyperkalemia). There is no specific antidote.

Food Animal Withdrawal Times

🥩 Meat: 1 days🥛 Milk: 1 days

Withdrawal times are not officially established for propofol in food animals. However, due to its rapid metabolism and short half-life, a conservative withdrawal time of 24 hours for meat and milk is often recommended. For eggs, no data available; use extra-label with caution. Always follow local regulations and veterinary guidance.

Storage, Handling & Regulatory Information

Storage Temperature: Store at controlled room temperature 20-25°C (68-77°F); do not refrigerate or freeze.

Handling & Special Conditions: Protect from light. Do not shake vigorously. Use within 6 hours of opening the vial. Discard any unused portion. Do not use if emulsion appears discolored or contains particulate matter.

Dispensing Status: Prescription Required (Rx Only)

Approval Status: Approved for use in dogs and cats (e.g., PropoFlo, Diprivan). Not approved for food animals, but may be used extra-label.

Extra-Label (Off-Label) Use: Propofol is not approved for all species; extra-label use in food animals is permitted under AMDUCA with appropriate withdrawal times and veterinary supervision. In the US, propofol is a prescription drug for veterinary use.

Clinical Pearls & Practice Notes

💡 Clinical Insights: Propofol is a valuable anesthetic agent in veterinary practice due to its rapid onset and smooth recovery. It is commonly used for induction of anesthesia, followed by inhalant maintenance, or as a continuous rate infusion for total intravenous anesthesia (TIVA). It is particularly useful for short procedures or when rapid recovery is desired. However, it requires careful monitoring of respiratory and cardiovascular function, especially in compromised patients. Premedication with sedatives or opioids can reduce the dose required and improve anesthetic stability. Propofol should be administered slowly to effect, and the use of a dedicated IV catheter is recommended. In food animals, extra-label use requires careful consideration of withdrawal times. Always have emergency drugs and equipment (e.g., oxygen, endotracheal tubes, ventilators) available when using propofol.

References & Literature

📚 Plumb's Veterinary Drug Handbook
📚 Papich Veterinary Pharmacology and Therapeutics
📚 Compendium of Veterinary Products (CVP)