Cyproheptadine

Cyproheptadine (trade name Periactin) ; usually as cyproheptadine hydrochloride is an antihistaminic/anticholinergic and antiserotonergic agent. It also acts as a 5-HT2 receptor antagonist as well as blocking calcium channels.

Uses
Cyproheptadine is used to treat allergic reactions (specifically hay fever).

Cyproheptadine has shown effectiveness in the treatment of nightmares including nightmares related to post traumatic stress disorder.

Cyproheptadine has been used in the management of moderate to severe cases of serotonin syndrome (a complex of symptoms associated with the use of serotonergic drugs, such as selective serotonin reuptake inhibitors and monoamine oxidase inhibitors),  and in the disease carcinoid in which serotonin is overproduced by tumor cells.

Cyproheptadine can also be used as a preventive measure against migraine in children and adolescents.

Cyproheptadine can relieve SSRI-induced sexual dysfunction and drug-induced hyperhydrosis (excessive sweating).

Cyproheptadine is also used in the treatment of cyclical vomiting syndrome and to stimulate the appetite.

Adverse effects
While not specifically used as a sedative, cyproheptadine causes drowsiness, as is common with first-generation antihistamines.

Research has shown a suppression of growth hormone with doses of 8–12 mg per day taken for 5 days.

Other common side effects include:
 * Dizziness
 * Blurred vision
 * Constipation
 * Dry mouth, throat, or nose
 * Excitability
 * Nausea
 * Nervousness
 * Restlessness or akathisia

Research
Cyproheptadine has been shown to improve quality of sleep in sleep-deprived rats.

Cyproheptadine interacts with several other medications such as MAOIs (monoamine oxidase inhibitors) and potassium salts and can cause adverse reactions. Anti-cholinergic medications such as Cyproheptadine, when used in conjunction with oral potassium salts, can cause slowing of GI transit and increases the local exposure to high potassium concentrations. High potassium concentrations may lead to GI tract ulceration or stenosis.

Veterinary use
Cyproheptadine is used in cats as an appetite stimulant and as an adjunct in the treatment of asthma. Possible adverse effects include excitement and aggressive behavior.

The elimination half-life of cyproheptadine in cats is 12 hours. . Cyproheptadine has been used successful in treatment of Pituitary Pars Intermedia Dysfunction (PPID) in horses.