Yohimbine
Yohimbine hydrochloride
Also known as: Yobine · Antagonil · Aphrodyne · Dayto Himbin · Pluriviron mono · Prowess Plain · Urobine · Virigen · Yocon · Yocoral · Yohimex · Yomax · Zumba · aphrodine hydrochloride · chlorhydrate de quebrachine · corynine hydrochloride · Yohydrol
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Audited v13 dosing evidence
Reviewed non-calculator evidenceReviewed non-calculator evidence (1)
Evidence only — not for automatic calculation
Xylazine reversal; rarely indicated; atipameazole commonly used to reverse all α2 agonists
TABLE 127.5. Agent: Yohimbine (Yobine, Lloyd). Dosage: —. Species/Comments: Xylazine reversal; rarely indicated; atipameazole commonly used to reverse all α2 agonists. Table note: a Medetomidine is no longer commercially available in North America, although it can be obtained from select compounding services; dosages are listed here as a guide for possible use with dexmedetomidine, an α 2 agonist that is the active optical enantiomer of racemic compound medetomidine; dexmedetomidine is generally used at half the dose of medetomidine but the same volume due to higher concentration; both compounds tend to have similar effects..
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Yohimbine is an indolealkylamine alkaloid and a specific alpha-2 adrenergic antagonist. It is primarily utilized in veterinary medicine to reverse the sedative and cardiovascular effects of alpha-2 agonists, particularly xylazine.
Beyond anesthetic reversal, yohimbine is highly effective as an antidote for amitraz toxicity (often seen with tick dips or collars) and can even be used prophylactically before amitraz administration. While its use for reversing modern alpha-2 agonists like dexmedetomidine has largely been supplanted by atipamezole, yohimbine remains a valuable emergency and reversal agent. It has also been investigated for use as an antiemetic in specific clinical scenarios.
Mechanism of action
Yohimbine competitively blocks central and peripheral presynaptic alpha-2 adrenergic receptors.
- Mechanism: By blocking these autoreceptors, yohimbine prevents the negative feedback loop that normally inhibits neurotransmitter release → increases synaptic norepinephrine release → enhances sympathetic outflow.
- Systemic Effects: This surge in sympathetic tone results in increased heart rate, elevated blood pressure, CNS stimulation, and antidiuresis, effectively counteracting the profound sedation, bradycardia, and hypotension induced by alpha-2 agonists.
Safety & warnings
Contraindications
- Hypersensitivity to yohimbine
- Renal disease (extrapolated from human medicine)
- Patients with active seizure disorders
Adverse effects
- Transient apprehension or anxiety
- CNS excitement
- Muscle tremors
- Hypersalivation
- Increased respiratory rate (panting)
- Hyperemic (red) mucous membranes
- Tachycardia
Precautions
Seizure Disorders: Use with extreme caution as yohimbine can lower the seizure threshold and induce tremors or convulsions. Renal Impairment: Contraindicated in humans with renal disease; use cautiously in veterinary patients with compromised kidney function.
Important Clinical Pearl - Analgesia Loss: Reversing xylazine or other alpha-2 agonists will simultaneously remove any provided analgesia. Normal pain perception will return immediately. Ensure alternative pain management (e.g., opioids, NSAIDs) is on board before administration if the patient underwent a painful procedure.
Drug interactions
May cause severe hypertension; concurrent use is not recommended.
Additive antagonistic effects; use with caution.
Additive CNS stimulation and increased risk of seizures or severe agitation.
Monitoring
- CNS status (arousal level, signs of excitement or apprehension)
- Cardiac rate and rhythm
- Blood pressure (if indicated and practical)
- Respiratory rate and effort
Pharmacokinetics
Half-life
Absorption
Rapid onset of action; when used to reverse xylazine IV, onset generally occurs within 3 minutes.
Distribution
Readily penetrates the blood-brain barrier into the CNS. Apparent volume of distribution (steady-state) is approximately 5 L/kg in steers, 2-5 L/kg in horses, and 4.5 L/kg in dogs.
Metabolism
The specific metabolic fate of yohimbine is currently unknown.
Elimination
Total body clearance is approximately 70 mL/min/kg in steers, 35 mL/min/kg in horses, and 30 mL/min/kg in dogs.
Overdose
Overdoses can cause significant CNS and cardiovascular overstimulation.
- Experimental Data: Dogs receiving 0.55 mg/kg (5 times the recommended dose) exhibited clinical signs of transient seizures and muscle tremors.
- Clinical Reports (APCC): Reported findings in dogs include diarrhea, disorientation, hyperactivity, panting, tachycardia, and hypersalivation.
- Treatment: Primarily supportive and symptomatic. Avoid further CNS stimulation and manage seizures if they occur.
Available products
Formulations
- Injection: 2 mg/mL sterile solution
- Oral tablets: 5.4 mg (Human-labeled)
Veterinary
- Yohimbine Sterile Solution for Injection: 2 mg/mL in 20 mL vials (Yobine®)
Human-labeled
- Oral tablets: 5.4 mg
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store injection at room temperature (15-30°C) and protect from light and heat.
Client information
This medication is strictly for use under direct veterinary supervision, typically in a clinic or hospital setting.
- Purpose: Used to quickly 'wake up' pets after sedation with certain drugs (like xylazine) or to treat toxicity from tick dips/collars containing amitraz.
- What to Expect: Your pet may wake up very suddenly. Brief periods of anxiety, panting, drooling, or muscle tremors are normal as the drug takes effect and usually resolve quickly.
- Pain Management: Because this drug reverses sedation, it also reverses pain relief. Your veterinarian will ensure other pain medications are given if your pet had a surgical or painful procedure.
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.