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trademark for preparations of cyproheptadine hydrochloride, an antihistamine used for relief of allergy and itching.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

cyproheptadine hydrochloride

Periactin (UK), PMS-Cyproheptadine (CA)

Pharmacologic class: Piperidine (nonselective)

Therapeutic class: Antihistamine

Pregnancy risk category B


Antagonizes effects of histamine at histamine1-receptor sites, preventing histamine-mediated responses. Also blocks effects of serotonin, causing increased appetite.


Syrup: 2 mg/5 ml

Tablets: 4 mg

Indications and dosages

Allergy symptoms caused by histamine release (including seasonal and perennial allergic rhinitis); chronic urticaria; angioedema; dermographism; cold urticaria; adjunctive therapy for anaphylactic reactions

Adults: Initially, 4 mg P.O. q 8 hours. Maintenance dosage is 4 to 20 mg/day in three divided doses, to a maximum dosage of 0.5 mg/kg/day.

Children ages 7 to 14: 2 to 4 mg P.O. q 12 hours. Don't exceed 16 mg/day.

Children ages 2 to 6: 2 mg P.O. q 12 hours. Don't exceed 12 mg/day.

Off-label uses

• Vascular cluster headaches

• Anorexia nervosa

• Cushing's syndrome


• Hypersensitivity to drug

• Alcohol intolerance (syrup only)

• Bladder neck obstruction

• Angle-closure glaucoma

• Ulcer disease

• Symptomatic prostatic hypertrophy

• MAO inhibitor use within past 14 days


Use cautiously in:

• hepatic impairment

• elderly patients

• pregnant patients (safety not established)

• breastfeeding patients.


• Give with food or milk to decrease GI upset.

Adverse reactions

CNS: drowsiness, dizziness, excitation (especially in children), fatigue, sedation, hallucinations, disorientation, tremor

CV: palpitations, hypotension, arrhythmias

EENT: blurred vision, nasal dryness and congestion, dry throat

GI: constipation, dry mouth

GU: urinary retention, urinary frequency, ejaculatory inhibition, early menses

Respiratory: thickened bronchial secretions

Skin: rash, photosensitivity

Other: weight gain


Drug-drug. CNS depressants (including opioid analgesics, sedative-hypnotics): increased CNS depression

MAO inhibitors: intensified, prolonged anticholinergic effects

Drug-diagnostic tests. Allergy skin tests: false-negative reactions

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

• Monitor patient for excessive anti-cholinergic effects.

• Assess for excessive CNS depression.

• Discontinue drug 4 days before diagnostic skin testing.

Patient teaching

• Advise patient to take drug with food to minimize GI upset.

• Caution patient not to use other CNS depressants, sleep aids, or alcohol during therapy.

• Instruct patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


A trademark for the drug cyproheptadine hydrochloride.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
A substance that had transient currency with some atheletes as it was believed to stimulate the appetite
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


A brand name for CYPROHEPTADINE.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
Her doctor also prescribed Periactin, thinking migraines could be causing her behavior.
Antihistamines (Combination, cold/hay fever products with decongestants) -- Chlor-trimeton (Ornade, Isochlor), Dimetane (Dimetapp), Benadryl, Tavist, Ambodryl, Clistin, Decapryn, Polaramine, Forhistal, Actidil (Actifed), PBZ, Histadyl, Tacaryl, Phenergan, Temaril, Atarax/Vistaril, Optimine, Periactin, Seldane, Hismanal
Cyproheptadine (Periactin) is used to treat cold-induced urticaria.
The children with cyclic vomiting who have asthma or who do not tolerate [beta]-blockers are started on an antihistamine such as cyproheptadine (Periactin).
Chlor-trimeton (Ornade, Isochlor) Dimetane (Dimetapp), Benadryl, Tavist, Ambodryl, Clistin, Decapryn, Polaramine, Forhistal, Actidil (Actifed), PBZ, Histadyl, Tacaryl, Phenergan, Temaril, Atarax/Vistaril, Optimine, Periactin, Seldane, Hismanal, Claritin