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cyproheptadine (sye-proe-hep-ta-deen)

Periactin, PMS-Cyproheptadine


Therapeutic: allergy, cold, and cough remedies, antihistamines

Pharmacologic: piperidines


Relief of allergic symptoms caused by histamine release including Seasonal and perennial allergic rhinitis; Chronic urticaria, Cold urticaria. Unlabeled Use: Stimulation of appetite.


Antagonizes the effects of histamine at H1 receptor sites; does not bind to or inactivate histamine. Also blocks the effects of serotonin, which may result in increased appetite. Therapeutic Effects: Decreased symptoms of histamine excess (sneezing, rhinorrhea, nasal and ocular pruritus, ocular tearing and redness). Decreased cold urticaria.

Adverse Reactions/Side Effects

CNS: drowsiness, excitation (increased in children). EENT: blurred vision. CV: arrhythmias, hypotension, palpitations. GI: dry mouth, constipation. GU: hesitancy, retention. Derm: photosensitivity, rashes. Misc: weight gain.


Examination and Evaluation

  • Assess blood pressure (BP) periodically and compare to normal values (See Appendix F). Report low BP (hypotension), especially if patient experiences dizziness or syncope.

  • Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report any rhythm disturbances or symptoms of increased arrhythmias, including palpitations, chest discomfort, shortness of breath, fainting, and fatigue/weakness.

  • Monitor symptoms of seasonal allergies (sneezing, rhinitis, itching eyes, cough) or chronic urticaria (rash, hives, itching) to help document benefits of this drug in treating these disorders.

  • Monitor signs of increased excitation in children. Severe or problematic excitation may require a change in dose or drug.

  • Periodically assess body weight and other anthropometric measures (body mass index, body composition). Report a rapid or unexplained weight gain or increased body fat.


  • Guard against falls and trauma (hip fractures, head injury, and so forth). Implement fall- prevention strategies, especially in older adults or if balance is impaired (See Appendix E).

  • Because of an increased risk of arrhythmias and abnormal BP responses, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (BP, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (See Appendix L).

  • Causes photosensitivity; use care if administering UV treatments. Advise patient to avoid direct sunlight and use sunscreens and protective clothing.

Patient/Client-Related Instruction

  • Advise patient about the risk of daytime drowsiness and decreased attention and mental focus. These problems can be severe in certain people. Use care if driving or in other activities that require quick reactions and strong concentration.

  • Advise patient to avoid alcohol and other CNS depressants because of the increased risk of sedation and adverse effects.

  • Instruct patient to report other troublesome side effects such as severe or prolonged skin rash, blurred vision, problems with urination, or GI problems (constipation, dry mouth).

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