What is Cyproheptadine (Periactin), an antihistamine?

From the Guidelines

Ciproheptadine should be used with caution due to its sedating properties and potential for anticholinergic effects, particularly in elderly patients or those with certain medical conditions, as noted in studies such as 1 and 1.

Overview of Ciproheptadine

Ciproheptadine is an antihistamine medication that works by blocking histamine H1 receptors, and it is available as a 4 mg tablet taken 3-4 times daily, with a typical adult dose ranging from 4-20 mg per day. It has several off-label uses, including migraine prevention, appetite stimulation in underweight patients, and management of serotonin syndrome, as discussed in 1. The medication antagonizes histamine and serotonin receptors, which helps reduce allergic symptoms like itching, hives, and nasal congestion.

Side Effects and Precautions

Common side effects of ciproheptadine include drowsiness, dry mouth, dizziness, and increased appetite. Patients should be aware that ciproheptadine may cause significant sedation, so activities requiring alertness should be avoided until tolerance develops. The medication should be used cautiously in elderly patients, those with glaucoma, urinary retention, or cardiovascular disease, as noted in 1 and 1. For children, dosing is weight-based, typically starting at 0.25 mg/kg/day divided into 2-3 doses.

Specific Considerations

• Dosing and Administration: The typical adult dose of ciproheptadine ranges from 4-20 mg per day, and it is available as a 4 mg tablet taken 3-4 times daily.
• Off-Label Uses: Ciproheptadine has several off-label uses, including migraine prevention, appetite stimulation in underweight patients, and management of serotonin syndrome, as discussed in 1.
• Side Effects: Common side effects of ciproheptadine include drowsiness, dry mouth, dizziness, and increased appetite, as noted in 1 and 1.
• Precautions: The medication should be used cautiously in elderly patients, those with glaucoma, urinary retention, or cardiovascular disease, as noted in 1 and 1.

Evidence-Based Recommendations

Based on the evidence from studies such as 1, 1, and 1, ciproheptadine should be used with caution due to its sedating properties and potential for anticholinergic effects, particularly in elderly patients or those with certain medical conditions. Additionally, patients should be aware of the potential for significant sedation and take precautions to avoid activities that require alertness until tolerance develops.

From the FDA Drug Label

CLINICAL PHARMACOLOGY Cyproheptadine is a serotonin and histamine antagonist with anticholinergic and sedative effects. Pharmacokinetics and Metabolism After a single 4 mg oral dose of 14C-labelled cyproheptadine hydrochloride in normal subjects, given as tablets, 2% to 20% of the radioactivity was excreted in the stools. Only about 34% of the stool radioactivity was unchanged drug, corresponding to less than 5. 7% of the dose. At least 40% of the administered radioactivity was excreted in the urine. No detectable amounts of unchanged drug were present in the urine of patients on chronic 12 mg to 20 mg daily doses. The principle metabolite found in human urine has been identified as a quaternary ammonium glucuronide conjugate of cyproheptadine. Elimination is diminished in renal insufficiency.

The main use of Ciproheptadine is as a serotonin and histamine antagonist with anticholinergic and sedative effects 2.

• Key points about Ciproheptadine include:
  • It is excreted in the stools and urine
  • Elimination is diminished in renal insufficiency
  • The principle metabolite is a quaternary ammonium glucuronide conjugate of cyproheptadine 2.

From the Research

Ciproheptadine Overview

• Ciproheptadine is an antihistamine with anticholinergic properties.
• There is limited information available on Ciproheptadine in the provided study.

Anticholinergic Side-Effects

• Anticholinergic drugs, including Ciproheptadine, have been associated with serious side-effects in elderly people 3.
• Common side-effects reported in the study include:
  • Drowsiness (65%)
  • Dry mouth (53%)
  • Dry eyes (53%)
  • Constipation (39%)
  • Blurred vision (39%)
  • Urinary hesitancy (28%)
  • Confusion (21%)
• The study suggests that reducing the use of anticholinergic drugs, such as Ciproheptadine, can improve drug safety 3.

Prescription and Evaluation

• The study found that none of the subjects were evaluated for fall risk or mental status by their doctors before being prescribed anticholinergic drugs, including Ciproheptadine 3.
• It is recommended that psychiatrists and family physicians select less anticholinergic drugs and evaluate their patients' fall risk and cognitive status before prescribing drugs with anticholinergic side effects, such as Ciproheptadine 3.