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Selegiline (L-Deprenyl)

Prescription
Monoamine oxidase B (MAO-B) inhibitor
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
3 available
Interactions
20 documented
Formulations
2

Mechanism of action

Selectively inhibits MAO-B, increasing dopamine concentrations in the CNS; used for cognitive dysfunction and pituitary-dependent Cushing's

At a glance

Class
Monoamine oxidase B (MAO-B) inhibitor
Schedule
Prescription
Storage
Store below 25°C, protect from moisture

Dosing

🐕

Dog

Cognitive dysfunction syndrome (CDS) / Pituitary-dependent hyperadrenocorticism
Dose
0.5–1 mg/kg
Route
PO
Frequency
SID (morning)
Max dose
30 mg
Duration: Long-term; 2-month trial recommended for CDS
🐈

Cat

Cognitive dysfunction syndrome
Dose
0.25–0.5 mg/kg
Route
PO
Frequency
SID (morning)
Max dose
5 mg
Duration: Long-term

Formulations

💊

Tablet — 2

Strength
5mg
Available in India
Strength
10mg
Available in India

Storage

Store below 25°C, protect from moisture

Safety

Absolute contraindications — do not use

  • Concurrent use of SSRIs, TCAs, or opioids (serotonin syndrome risk)
    Allow 2-week washout
    FluoxetineClomipramineTramadol
  • Known hypersensitivity

Adverse effects

Common
Restlessness
Decreased appetite
Disorientation (transient)
Serious
Serotonin syndrome (with drug interactions)
Stereotypic behavior

Monitoring parameters

Behavioral improvement assessmentAppetite

Interactions

Contraindicated — 14

Tramadol
contraindicated
Risk of serotonin syndrome — selegiline (MAO-B inhibitor) + tramadol (serotonin reuptake inhibitor)
Management: Do not combine. Allow 14-day washout from selegiline before starting tramadol.
Fluoxetine
contraindicated
Risk of serotonin syndrome — MAO inhibitor + SSRI combination is absolutely contraindicated
Management: Never combine. Allow 14-day washout from selegiline and 5-week washout from fluoxetine.
Sertraline
contraindicated
SSRI + MAO inhibitor: high risk of fatal serotonin syndrome
Management: Absolutely contraindicated. Allow 14-day washout from selegiline before starting any SSRI.
Meperidine (Pethidine)
contraindicated
Meperidine + MAO inhibitor: potentially fatal serotonergic crisis with hyperthermia, rigidity, seizures, cardiovascular collapse.
Management: ABSOLUTE CONTRAINDICATION. Never combine meperidine with any MAO inhibitor. Use alternative opioid (morphine, hydromorphone).
Clomipramine
contraindicated
TCA (serotonin reuptake inhibitor) + MAO inhibitor: serotonin syndrome.
Management: NEVER combine. Allow 2-week washout between agents.
Linezolid
contraindicated
Two MAO inhibitors (linezolid: reversible MAO-A; selegiline: irreversible MAO-B, with MAO-A activity at high doses): risk of hypertensive crisis and serotonin syndrome.
Management: NEVER combine. Allow 2-week washout of selegiline before linezolid.
Paroxetine
contraindicated
SSRI + MAO inhibitor: serotonin syndrome — hyperthermia, seizures, rigidity, death.
Management: NEVER combine. Allow 2-week washout of paroxetine before selegiline.
Dextromethorphan
contraindicated
DXM has serotonergic properties + selegiline is MAO inhibitor. Risk of serotonin syndrome.
Management: NEVER combine. Use alternative antitussive.
Fluvoxamine
contraindicated
SSRI + MAO inhibitor: serotonin syndrome — potentially fatal.
Management: NEVER combine. Allow 2-week washout of either before starting the other.
Imipramine
contraindicated
TCA (serotonin/norepinephrine reuptake inhibitor) + MAO inhibitor: serotonin syndrome.
Management: NEVER combine. Allow 2-week washout between agents.
Doxepin
contraindicated
TCA + MAO inhibitor: serotonin syndrome.
Management: NEVER combine. Allow 2-week washout between agents.
Ephedrine
contraindicated
Ephedrine releases stored norepinephrine + selegiline inhibits MAO breakdown of catecholamines: massive catecholamine surge causing severe hypertension, hyperthermia, seizures.
Management: NEVER combine. Allow 2-week washout of selegiline before ephedrine.
Phenylpropanolamine
contraindicated
PPA releases norepinephrine + MAO inhibitor prevents catecholamine breakdown: hypertensive crisis.
Management: NEVER combine. Use alternative urinary incontinence therapy (estriol, DES) with selegiline.
Pseudoephedrine
contraindicated
Sympathomimetic + MAO inhibitor: severe hypertensive crisis and potentially fatal cardiovascular collapse.
Management: NEVER combine.

Major — 4

Methadone
major
Methadone has weak serotonin reuptake inhibition + selegiline is MAO-B inhibitor: risk of serotonin syndrome.
Management: Avoid combination. If opioid needed with selegiline, use morphine or hydromorphone (no serotonergic activity).
Mirtazapine
major
Mirtazapine (increases serotonin/norepinephrine release) + MAO inhibitor: serotonin syndrome risk.
Management: Avoid. Allow 2-week washout of selegiline before mirtazapine.
Methylphenidate
major
Methylphenidate increases catecholamine levels + selegiline inhibits MAO-B: risk of hypertensive crisis and CNS overstimulation.
Management: Avoid combination.
Hydrocodone
major
Opioid + MAO inhibitor: risk of serotonin syndrome and enhanced CNS/respiratory depression.
Management: Avoid. Use non-opioid antitussive if cough suppressant needed with selegiline.

Moderate — 2

Amantadine
moderate
Both increase CNS catecholamine levels (amantadine: dopamine release; selegiline: MAO-B inhibition). Additive CNS stimulation.
Management: Monitor for CNS excitation (restlessness, agitation). Reduce doses if combining.
Buspirone
moderate
Buspirone (5-HT1A partial agonist) + selegiline (MAO-B inhibitor): theoretical serotonin accumulation risk. Clinical significance in veterinary patients is unclear.
Management: Use with caution. Monitor for serotonin syndrome signs. Generally considered lower risk than SSRI + MAOI combinations.

Brands

International

Anipryl
Zoetis

India

Selgin
Intas
Selegiline
Sun Pharma

FAQs

Frequently asked questions

›What is Selegiline (L-Deprenyl)?
Selegiline (L-Deprenyl) is a monoamine oxidase b (mao-b) inhibitor used in pets. Selectively inhibits MAO-B, increasing dopamine concentrations in the CNS; used for cognitive dysfunction and pituitary-dependent Cushing's
›What is Selegiline (L-Deprenyl) used for in pets?
Selegiline (L-Deprenyl) is used in veterinary medicine for: Cognitive dysfunction syndrome (CDS) / Pituitary-dependent hyperadrenocorticism; Cognitive dysfunction syndrome.
›What is the Selegiline (L-Deprenyl) dose for dogs?
For dogs, Selegiline (L-Deprenyl) is typically dosed as follows — Cognitive dysfunction syndrome (CDS) / Pituitary-dependent hyperadrenocorticism: 0.5–1 mg/kg PO SID (morning). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Selegiline (L-Deprenyl) dose for cats?
For cats, Selegiline (L-Deprenyl) is typically dosed as follows — Cognitive dysfunction syndrome: 0.25–0.5 mg/kg PO SID (morning). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What are the side effects of Selegiline (L-Deprenyl)?
Common: Restlessness, Decreased appetite, Disorientation (transient). Serious (call your vet immediately): Serotonin syndrome (with drug interactions), Stereotypic behavior.
›Does Selegiline (L-Deprenyl) need a prescription?
Yes. Selegiline (L-Deprenyl) is a prescription medication and should only be administered under veterinary supervision.
›When should Selegiline (L-Deprenyl) not be used?
Do not use Selegiline (L-Deprenyl) if: Concurrent use of SSRIs, TCAs, or opioids (serotonin syndrome risk); Known hypersensitivity.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
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 →