An antihistamine is a type of medicine used to treat common allergy symptoms, such as sneezing, watery eyes, hives, and a runny nose. According to the American College of Allergy, Asthma. Tramadol is used primarily to treat mild to severe pain, both acute and chronic. Its analgesic effects take about one hour to come into effect and 2 to 4 h to peak after oral administration with an immediate-release formulation. Cyproheptadine (cyproheptadine hydrochloride) is an antihistamine used to treat sneezing, itching, watery eyes, runny nose, and other symptoms of allergies. 懷孕時期的用藥，須相當謹慎，某些藥物可能影響胎兒的成長與安全，造成胎兒的畸形。美國 fda基於懷孕用藥的安全性，將懷孕藥品分為下列五級(詳細定義附於文後)： Cyproheptadine is used to treat allergic reactions (specifically hay fever). The evidence for its use for this purpose in children is weak and ketotifen and loratadine showed equal or better results in the small trials in which they have been compared. Periactin is the brand name for cyproheptadine for an antihistamine that is used to treat allergic reactions, including skin reactions, by blocking histamines. It also is used to prevent migraine headaches. There are a variety of side effects of this drug, for example, itching, nausea, and vomiting. Cyproheptadine, an antiserotonin agent, has been studied in habitual aborters with increased serotonin levels. No malformations have been reported. New England Journal of Medicine CORRECTION Current Concepts: The Serotonin Syndrome Current Concepts: The Serotonin Syndrome. The legend for Figure Cyproheptadine HCl, USP is an antihistaminic and antiserotonergic agent. Cyproheptadine hydrochloride, USP is a white to slightly yellowish crystalline solid, with a molecular weight of 350.89, which is soluble in water, freely soluble in methanol, sparingly soluble in ethanol, soluble in chloroform, and practically insoluble in ether. Cyproheptadine is contraindicated for use in neonates and premature infants and generally should not be used in infants of any age. Use cyproheptadine with caution in children because a paradoxical CNS stimulation and/or respiratory depression can occur.