Common use

Cyproheptadine is a first-generation antihistamine with additional antiserotonergic properties, making it a uniquely versatile medication with multiple clinical applications. As an antihistamine, Cyproheptadine works by blocking H1 histamine receptors throughout the body, effectively relieving or preventing the symptoms of hay fever (seasonal allergic rhinitis), perennial allergic rhinitis, allergic conjunctivitis, urticaria (hives), and other allergic conditions. By blocking the effects of histamine — a natural substance produced by the body during allergic reactions — Cyproheptadine reduces sneezing, runny nose, itchy and watery eyes, and skin rashes.

Beyond its antihistamine action, Cyproheptadine (also known by the brand name Periactin) possesses significant anti-serotonin activity, which makes it valuable for several additional indications. It is widely used as an appetite stimulant in underweight patients, children with poor appetite, and individuals recovering from illness or surgery. Cyproheptadine is also prescribed for the prevention and treatment of migraine headaches, cluster headaches, and serotonin syndrome. Its anticholinergic and anti-serotonin properties also make it useful for managing symptoms of carcinoid syndrome and preventing vascular headaches. Additionally, Cyproheptadine can help control nausea, vomiting, dizziness, and motion sickness. When you buy Cyproheptadine online, you get a multi-purpose antihistamine and appetite stimulant that addresses allergies, headaches, and weight management needs in one convenient medication.



Dosage and direction

Always consult your doctor before starting Cyproheptadine and use only the prescribed amount. Take each dose with a full glass of water, with or without food. The maximum daily dose of Cyproheptadine should not exceed 32 mg for adults.

The recommended dose for adults is 4 milligrams (1 tablet) taken 3 times daily. Depending on the individual patient's response and the condition being treated, the daily dosage may range from 4 mg to 20 mg, with the most commonly effective range being 12 mg to 16 mg per day. For elderly patients (over 65 years of age), doctors will generally prescribe a lower starting dose and titrate upward cautiously to minimize the risk of sedation and anticholinergic side effects.

For children aged 7 to 14 years, the recommended dose is 4 milligrams (1 tablet) taken 2 or 3 times daily, with a maximum daily dose of 16 milligrams. For children aged 2 to 6 years, the recommended dose is 2 milligrams (one-half tablet) taken 2 or 3 times daily, with a maximum daily dose of 12 milligrams. When using Cyproheptadine as an appetite stimulant, your doctor may start with a lower dose and gradually increase it based on your weight gain response.

Note: These dosing instructions are provided for informational purposes only. Your healthcare provider will determine the most appropriate dose for your specific condition and medical profile.



Precautions

Cyproheptadine can cause significant drowsiness, sedation, and impaired coordination, particularly when first starting the medication or when the dose is increased. Exercise caution while driving, climbing, operating machinery, or performing any activity requiring mental alertness and physical coordination until you know how Cyproheptadine affects you. Alcohol consumption should be avoided or minimized while taking this medication, as it can intensify drowsiness and sedation. Use Cyproheptadine with additional caution if your medical history includes bronchial asthma, chronic obstructive pulmonary disease (COPD), narrow-angle glaucoma, hyperthyroidism (overactive thyroid), high blood pressure, cardiovascular disease, or circulatory problems. Cyproheptadine is not recommended during pregnancy, in women planning to become pregnant, or during breastfeeding, as the drug may pass into breast milk and affect the nursing infant. Do not use before breastfeeding without first obtaining medical advice from your healthcare provider.



Contraindications

Cyproheptadine is contraindicated in the following patients and conditions:

Patients currently experiencing an acute asthmatic attack — antihistamines may thicken bronchial secretions and worsen breathing difficulties;

Newborn infants and premature babies — use in neonates has been associated with apnea, cyanosis, and serious respiratory distress;

Breastfeeding mothers — Cyproheptadine is excreted in breast milk and may cause adverse effects in nursing infants;

Patients with known hypersensitivity to cyproheptadine hydrochloride or drugs with a similar chemical structure;

Concurrent use with monoamine oxidase (MAO) inhibitors — the combination can lead to dangerously intensified anticholinergic effects;

Patients with narrow-angle glaucoma — anticholinergic effects may precipitate an acute glaucoma crisis;

Patients with pyloroduodenal obstruction, stenosing peptic ulcer, symptomatic prostatic hypertrophy, bladder neck obstruction, or predisposition to urinary retention;

Elderly and debilitated patients who may be particularly sensitive to the sedative and anticholinergic effects of antihistamines.



Possible side effect

Seek immediate medical attention if you experience signs of a serious allergic reaction to Cyproheptadine: hives, difficulty breathing, or swelling of the face, lips, tongue, or throat. Other potentially serious side effects that require prompt medical evaluation include:

Confusion, hallucinations, unusual thoughts or behavior, or personality changes;

Seizures (convulsions);

Tinnitus (ringing in the ears);

Feeling faint or lightheaded, as if you might pass out;

Fast, pounding, or irregular heartbeat;

Easy bruising or unusual bleeding;

Decreased urination or inability to urinate;

Pale or yellowed skin, dark-colored urine, unexplained fever, or unusual weakness (possible signs of blood disorders or liver problems).

Less serious and more common side effects of Cyproheptadine include:

Mild drowsiness, dizziness, or spinning sensation (vertigo);

Restlessness or excitability, especially in children;

Sleep difficulties (insomnia) or excessive tiredness;

Numbness or tingling sensations;

Increased sweating or changes in urination patterns;

Blurred vision;

Appetite changes (increased appetite is common and may be desired in underweight patients);

Dry mouth, dry nose, or upset stomach;

Nausea, diarrhea, or constipation.

If you experience any side effect that persists or seems unusual, stop taking Cyproheptadine and consult your healthcare provider promptly.



Drug interaction

Cyproheptadine has significant interactions with monoamine oxidase (MAO) inhibitors, including isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), and tranylcypromine (Parnate) — concurrent use is strictly contraindicated. Cyproheptadine may also reduce the effectiveness of selective serotonin reuptake inhibitor (SSRI) antidepressants due to its anti-serotonin properties. The sedative effects of Cyproheptadine can be enhanced by alcohol, benzodiazepines, opioid pain medications, other antihistamines, sleep aids, and muscle relaxants. Note that an interaction between two medications does not always mean you must discontinue one of them. In many cases, your doctor can manage the interaction through dosage adjustments or scheduling changes. Always inform your healthcare provider about all medications, supplements, and herbal products you are taking.



Missed dose

If you forget to take your dose on time, take it as soon as you remember. However, if it is already close to the time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double or extra dose to compensate for the missed one. Resume taking your usual dose at the next regularly scheduled time.



Overdose

Symptoms of Cyproheptadine (Periactin) overdose may include extreme drowsiness, severe confusion, hallucinations, very dry mouth, excessively dilated pupils, pale or flushed skin, vomiting, agitation, seizures, or loss of consciousness. In children, overdose symptoms may present as overexcitement rather than sedation. If you suspect a Cyproheptadine overdose, call your local poison control center or seek emergency medical attention immediately. Do not attempt to induce vomiting unless specifically instructed to do so by a healthcare professional.



Storage

Store Cyproheptadine at room temperature between 59-77 degrees F (15-25 degrees C) in a dry location away from direct light and moisture. Keep all medications securely out of the reach of children and pets. Do not use Cyproheptadine after the expiration date printed on the packaging, and properly dispose of any outdated or unused medication.



Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.