Periactin

Periactin (cyproheptadine hydrochloride) is a prescription antihistamine with notable serotonin and histamine antagonist properties, clinically recognized for its secondary benefit as an appetite stimulant. It is primarily indicated for the management of allergic conditions but is widely utilized off-label to address significant, unintentional weight loss and poor nutritional intake. By modulating key neurotransmitters in the hypothalamic appetite centers, Periactin helps promote a healthier caloric consumption, supporting patients in achieving and maintaining a healthier body mass. Its well-established pharmacological profile makes it a trusted option under physician guidance for specific clinical scenarios requiring weight gain support.

Features

• Active ingredient: Cyproheptadine Hydrochloride
• Available in 4 mg tablets and a 2 mg/5 mL syrup formulation
• Functions as a potent serotonin and histamine H1-receptor antagonist
• Prescription-only medication requiring medical supervision
• Typically administered in divided daily doses

Benefits

• Promotes measurable increase in appetite and caloric intake
• Supports healthy weight gain in patients experiencing malnutrition or cachexia
• May improve overall nutritional status and energy levels
• Can be beneficial in pediatric failure-to-thrive cases under specialist care
• Provides an alternative therapeutic pathway when other appetite stimulants are unsuitable
• Helps mitigate weight loss associated with certain chronic conditions or treatments

Common use

Periactin is FDA-approved for the relief of allergy symptoms, including perennial and seasonal allergic rhinitis, allergic conjunctivitis, and mild urticaria. Its off-label use as an appetite stimulant is supported by clinical experience and literature, particularly in contexts such as cachexia related to chronic disease (e.g., cancer, HIV/AIDS), failure to thrive in children, and weight loss associated with advanced age or depression. It is also sometimes used to support weight restoration in eating disorder management, though always as part of a comprehensive treatment plan.

Dosage and direction

Dosage must be individualized under medical supervision. For appetite stimulation in adults, the typical starting dose is 4 mg three times daily, which may be adjusted based on response and tolerability, not to exceed 32 mg per day. In pediatric patients (ages 2–14), dosage is weight-based, generally starting at 0.25 mg/kg/day or 8 mg/m²/day in divided doses. Administration with food may help reduce gastrointestinal discomfort. Regular follow-up is essential to evaluate efficacy and adjust dosing.

Precautions

Use with caution in patients with a history of asthma, increased intraocular pressure, hyperthyroidism, cardiovascular disease, or hypertension. May cause drowsiness; patients should avoid driving or operating machinery until their response is known. Elderly patients may be more sensitive to anticholinergic and sedative effects. Discontinue at least 4 days prior to skin allergy testing to avoid false negatives. Not recommended during pregnancy unless clearly needed.

Contraindications

Hypersensitivity to cyproheptadine or any component of the formulation. Should not be used in neonates or premature infants. Contraindicated in patients with angle-closure glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, or bladder neck obstruction. Avoid use in those taking monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing them.

Possible side effect

Common side effects include drowsiness, dizziness, dry mouth, nausea, and increased appetite. Less frequently, patients may experience restlessness, excitation (especially in children), blurred vision, sweating, or chills. Although rare, serious effects such as hypotension, palpitations, allergic reactions, or blood dyscrasias may occur. Patients should report any severe or persistent adverse effects to their healthcare provider.

Drug interaction

Periactin may potentiate the effects of CNS depressants, including alcohol, sedatives, and tranquilizers. Concurrent use with MAOIs is contraindicated. Anticholinergic effects may be enhanced when used with other anticholinergic drugs. Cyproheptadine may antagonize the effects of serotonin agonists. Always inform your prescriber of all medications, including over-the-counter drugs and supplements.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next dose. Do not double the dose to make up for a missed one. Maintain regular dosing schedule to ensure consistent therapeutic effect.

Overdose

Symptoms of overdose may include severe CNS depression (drowsiness, coma) or stimulation (hallucinations, convulsions), anticholinergic effects (flushed skin, hyperthermia), and cardiovascular collapse. In case of suspected overdose, seek emergency medical attention immediately. Treatment is supportive and may include gastric lavage, activated charcoal, and symptomatic management.

Storage

Store at room temperature (20–25°C or 68–77°F), away from light, moisture, and heat. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging.

Disclaimer

This information is intended for educational purposes and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting or changing any medication regimen. Individual responses to medication may vary.

Reviews

Clinical studies and patient reports frequently note improved appetite and gradual weight gain with Periactin use, particularly in cachectic and pediatric populations. Many users report a significant increase in hunger within the first week of treatment. However, sedation is a commonly cited drawback. Physician supervision is emphasized to balance benefits against side effects and to ensure appropriate patient selection.