Cyproheptadine is a first-generation antihistamine medication with additional anticholinergic and antiserotonergic properties. It provides rapid relief of symptoms but may cause sedation and other CNS side effects. Brand names: Periactin, Ciplactin, Cyheptine, Cyprogin, Cyprono, Cyprosian, Klarivitina, Nuran, Periactine, Periactinol, Peritol, Polytab, Practin, Preptin, Supersan, Trimetabol.
Key points:
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Mechanism: Cyproheptadine blocks the effects of histamine at H1 receptors, thereby reducing allergic symptoms such as sneezing, itching, watery eyes, and runny nose. Additionally, it has anticholinergic effects, which contribute to its ability to alleviate symptoms such as nausea, vomiting, and motion sickness. Cyproheptadine also acts as a serotonin antagonist, which may contribute to its appetite-stimulating effects.
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Indications: For the treatment of various allergic conditions, including allergic rhinitis (hay fever), allergic conjunctivitis, and allergic dermatitis. It is also used off-label for other conditions such as appetite stimulation in underweight individuals, migraine prophylaxis, and serotonin syndrome.
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Administration: The usual adult dose is 4 mg taken orally every 8 to 12 hours. Cyproheptadine is typically taken with water, with or without food.
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Onset and Duration of Action: Cyproheptadine has a relatively rapid onset of action, with symptom relief typically occurring within 30 minutes to 1 hour after oral administration. The duration of action is generally 4 to 6 hours per dose, requiring multiple daily doses for sustained relief of symptoms.
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Safety: Cyproheptadine has central nervous system (CNS) side effects compared to second-generation antihistamines. Common side effects may include drowsiness, dizziness, dry mouth, blurred vision, constipation, and urinary retention.
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Contraindications: Do not use in patients with narrow-angle glaucoma, urinary retention, severe liver disease, or severe respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD). Use with caution in elderly patients, as they may be more susceptible to CNS side effects such as drowsiness and dizziness. Dosage adjustments may be necessary based on renal function in patients with impaired kidney function.