Uses

Clemastine is indicated for the relief of symptoms associated with allergic rhinitis such as sneezing, rhinorrhoea, pruritus, and lacrimation. It is also indicated for mild uncomplicated urticaria and angioedema at the appropriate dosage.

Do not use if

Contraindicated in patients hypersensitive to clemastine or other antihistamines of similar chemical structure. Should not be used in newborns or premature infants due to the heightened risk of severe adverse effects.

Side effects

The most frequent adverse effects include sedation, somnolence, dizziness, and disturbed coordination. Gastrointestinal disturbances such as epigastric distress, nausea, and dry mouth may also occur. Anticholinergic effects including urinary retention and blurred vision have been reported.

Warnings

Use with considerable caution in patients with narrow-angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, prostatic hypertrophy, or bladder neck obstruction. Clemastine has additive CNS depressant effects when combined with alcohol or other CNS depressants.

How it works

Clemastine is a first-generation H1 antihistamine with anticholinergic and sedative properties. It competitively antagonises histamine at H1 receptors, reducing capillary permeability, oedema formation, pruritus, and smooth muscle contraction in the gastrointestinal and respiratory tracts.

Storage

Store at controlled room temperature between 20°C and 25°C (68°F and 77°F) as specified by USP.