Brand Name: N/A

Generic Name: Cyproheptadine

Drug Class: Antihistamines, 1st Generation

What Is Cyproheptadine and How Does It Work?

Cyproheptadine is an antihistamine used to treat sneezing, itching, watery eyes, runny nose, and other symptoms of allergies.

Dosages of Cyproheptadine:

Adult and Pediatric Dosage Forms and Strengths


Oral solution

  • 2 mg/5 mL

Dosage Considerations – Should be Given as Follows:

Hypersensitivity Reaction

  • Adults: 4 mg orally every 8 hours initially; maintenance: 4-20 mg/day, up to 32 mg/day divided every 8 hours in some patients; not to exceed 0.5 mg/kg/day
  • Children under 2 years old: Safety and efficacy not established
  • Children 2-6 years old: 2 mg orally every 8-12 hours; not to exceed 12 mg/day
  • Children 7-14 years old: 4 mg orally every 8-12 hours; not to exceed 16 mg/day
  • Alternatively, total daily dose of 0.25 mg/kg or 8 mg/m²

Spasticity Associated With Spinal Cord (Off-label)

  • 2-4 mg orally every 8 hours initially; not to exceed 24 mg/day

Migraine Headache Prophylaxis (Off-Label)

  • Adults: 2 mg orally every 12 hours with or without propanol
  • Pediatric, Prophylaxis
  • Children under 3 years: Safety and efficacy not established
  • Children over 3 years and adolescents: 0.2-0.4 mg/kg/day orally divided twice daily; not to exceed 0.5 mg/kg/day

Decreased Appetite Secondary to Chronic Disease (Off-label)

  • Adults: 2 mg orally every 6 hours for one week; THEN 4 mg orally every 6 hours
  • Pediatric, Stimulation of appetite
  • Children under 13 years: Safety and efficacy not established
  • Children over 13 years: 2 mg orally every 6 hours initially; increased to up to 8 mg every 6 hours over 3 weeks

Drug-Induced Sexual Dysfunction (Off-label)

  • 4-12 mg orally 1-2 hours before anticipated coitus or 1-16 mg/day

Serotonin Syndrome (Off-Label)

  • 12 mg initially orally, followed by 2 mg every 2 hours or 4-8 mg orally every 6 hours as needed to control symptoms

Dosing Modifications

  • Non-anticholinergic antihistamines should be considered first when treating allergic reactions (Beers Criteria)
  • Advanced age is associated with reduced clearance and greater risk of confusion, dry mouth, constipation, and other anticholinergic effects and toxicity; use lower end of dosage range (4 mg orally every 12 hours) for elderly patients, or administer less frequently
  • Renal impairment: Elimination is reduced in renal insufficiency; administer lower doses, and monitor closely

Dosing Modifications

  • Hepatic impairment: Give 75% of normal dose if transaminase levels are greater than 3 times upper limit of normal (ULN) or bilirubin is 3.1-5 mg/dL
  • Renal impairment: CrCl less than 10 mL/minute, give 75% of normal dose; CrCl greater than 10 mL/minute, give full dose


Could I Be Allergic? Discover Your Allergy Triggers See Slideshow

What Are Side Effects Associated with Using Cyproheptadine?

Common side effects of cyproheptadine include:

Serious side effects of cyproheptadine include:

  • Mental/mood changes (such as restlessness, confusion, hallucinations)
  • Shaking (tremors)
  • Difficult or painful urinating
  • Fast/irregular heartbeats (arrhythmias) (e.g., extrasystole, heart block)

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Cyproheptadine?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

Severe Interactions of cyproheptadine include:

Serious Interactions of cyproheptadine include:

  • desvenlafaxine
  • eluxadoline
  • isocarboxazid
  • phenelzine
  • procarbazine
  • sodium oxybate
  • tranylcypromine

Cyproheptadine has moderate interactions with at least 233 different drugs.

Mild Interactions of cyproheptadine include:

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns or for more information about this medicine.


Allergies can best be described as: See Answer

What Are Warnings and Precautions for Cyproheptadine?


This medication contains cyproheptadine. Do not take if you are allergic to cyproheptadine or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


Effects of Drug Abuse

  • None

Short-Term Effects

  • May cause central nervous system (CNS) depression, which may impair mental abilities; use caution when operating heavy machinery.
  • Antihistamines may cause excitation in young children.
  • See "What Are Side Effects Associated with Using Cyproheptadine?"

Long-Term Effects

  • Risk of potentially fatal and irreversible interstitial pulmonary fibrosis if given over prolonged periods.
  • See "What Are Side Effects Associated with Using Cyproheptadine?"


Pregnancy and Lactation

  • Cyproheptadine may be acceptable for use during pregnancy. Either animal studies show no risk but human studies are not available or animal studies showed minor risks and human studies were done and showed no risk.
  • Cyproheptadine excretion in milk is unknown; its use is contraindicated while breastfeeding.

From WebMD Logo

Medscape. Cyproheptadine.
RxList. Cyproheptadine Side Effects Drug Center.

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