Cyproheptadine: What is it? Indications, Dosage, Administration, Adverse Reactions, Interactions and Overdose

It is an antihistamine and antiserotonergic agent.

Cyproheptadine hydrochloride is a white to slightly yellowish crystalline solid with a molecular weight of 350.89.

This is soluble in water, freely soluble in methanol, sparingly soluble in ethanol and chloroform, and practically insoluble in ether.

What are the possible side effects of Cyproheptadine?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop taking Cyproheptadine and call your doctor at once if you have severe side effects, such as:

  • Confusion, hallucinations.
  • Thoughts or unusual behavior
  • Convulsions.
  • Strange sound in your ears.
  • Feeling that you can faint.
  • Fast or strong heartbeat.
  • Ease of bruising or bleeding.
  • Urinating less than usual or nothing at all.
  • Skin pale or yellowish.


Adherence to epinephrine and other standard measures after acute manifestations has been controlled as therapy for anaphylactic reactions.

Dosage and Administration

Each tablet contains 4 mg of cyproheptadine hydrochloride.


Pediatric patients

Age 2 to 6 years

The total daily dose for pediatric patients can be calculated based on body weight or body area using approximately 0.25 mg/kg/day or 8 mg per square meter of body surface area (8 mg / m2).

The usual dose is 2 mg (1/2 tablet) two or three times a day, adjusted as necessary for the size and response of the patient. The female should not exceed 12 mg per day.

From 7 years to 14 years

The usual dose is 4 mg (1 tablet) two or three times a day, adjusted as necessary for the size and response of the patient. The dose should not exceed 16 mg per day.


The total daily dose for adults should exceed 0.5 mg/kg/day. The therapeutic range is 4 to 20 mg daily, and most patients require 12 to 16 mg daily.

An occasional patient may require as much as 32 mg a day for adequate relief. It is suggested that the dosage be started with 4 mg (1 tablet) three times a day and adjusted according to the size and response of the patient.

Adverse reactions

The adverse reactions that have been reported with the use of antihistamines are the following:

Central Nervous System

Sedation and drowsiness (often transient), dizziness, altered coordination, confusion, restlessness, excitement, nervousness, tremor, irritability, insomnia, paresthesias, neuritis, seizures, euphoria, hallucinations, hysteria, fainting.

Digestive system

Cholestasis, liver failure, hepatitis, abnormal liver function, dry mouth, epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation, and jaundice.


Urinary frequency, difficulty urinating, urinary retention, early menstruation.


Dryness of the nose and throat, thickening of bronchial secretions, tight chest and wheezing, and nasal congestion.


Fatigue, chills, headache, increased appetite/weight gain.


Inhibitors prolong and intensify the anticholinergic effects of antihistamines. Antihistamines can have cumulative effects with alcohol and other CNS depressants, p. hypnotics, sedatives, tranquilizers, and anxiolytic agents.


Overdose reactions to antihistamines can vary from central nervous system depression to stimulation, especially in pediatric patients.

In addition, signs and symptoms similar to atropine may be present (dry mouth, dilated, fixed pupils, redness, etc.) and gastrointestinal symptoms.

If vomiting has not occurred spontaneously, the patient should be induced to vomit with ipecacuanha syrup.

If the patient can not vomit, perform a gastric lavage followed by activated charcoal. Isotonic or isotonic saline solution 1/2 is the wash of choice. Precautions should be taken against aspiration, especially in infants and children.

When the CNS’s signs and symptoms threaten life, intravenous administration of physostigmine salicylate can be considered.

The dose and frequency of administration depend on age, clinical response, and recurrence after the response. (Consult the package circulars for the physostigmine products).

Saline cathartics, such as milk of magnesia, by osmosis extract water into the intestine and, therefore, are valuable for their action in the rapid dilution of intestinal contents.

Stimulants should not be used.

Vasopressors can be used to treat hypotension.

The oral LD ​​of Cyproheptadine is 123 mg/kg, and 295 mg/kg in the mouse and the rat, respectively.


Newborn or Premature Babies

This medicine should not be used in premature newborns or newborns.

Nursing mothers

Due to the increased risk of antihistamines for babies, newborns, and premature babies, antihistamine therapy is contraindicated in nursing mothers.

Other conditions

  • Hypersensitivity to Cyproheptadine and other drugs of similar chemical structure.
  • Treatment with monoamine oxidase inhibitors.
  • Closed-angle glaucoma.
  • Stenosing of peptic ulcer.
  • Symptomatic prostatic hypertrophy.
  • Obstruction of the neck of the bladder.
  • Pyloroduodenal obstruction.
  • Elderly and debilitated patients.