Overview
Dimetindene is a first-generation antihistamine with anticholinergic and sedative properties, primarily used for symptomatic relief of allergic conditions. It is a selective histamine H1-receptor antagonist that also exhibits some antiserotonin activity.
Mechanism of Action
Competitively blocks histamine H1 receptors, preventing histamine-mediated allergic responses. Also possesses anticholinergic properties that contribute to its antipruritic effects and sedative side effects.
Indications
- Allergic rhinitis
- Allergic conjunctivitis
- Urticaria (hives)
- Pruritus (itching) of various origins
- Allergic skin reactions
- Symptomatic relief of common cold symptoms
Dosage
Adults and children over 12 years: 1 mg 2-3 times daily. Children 6-12 years: 0.5-1 mg 2-3 times daily. Maximum daily dose: 6 mg for adults, 3 mg for children. Should be taken with food to minimize gastrointestinal discomfort.
Contraindications
- Hypersensitivity to dimetindene or other antihistamines
- Angle-closure glaucoma
- Prostatic hypertrophy with urinary retention
- Pyloroduodenal obstruction
- Neonates and premature infants
- Concurrent use with MAO inhibitors
Side Effects
- Drowsiness/sedation
- Dry mouth
- Gastrointestinal disturbances
- Dizziness
- Headache
- Fatigue
- Blurred vision
- Urinary retention
- Paradoxical CNS stimulation (especially in children)
Interactions
- CNS depressants (alcohol, benzodiazepines, opioids) - enhanced sedation
- MAO inhibitors - increased anticholinergic effects
- Anticholinergic drugs - additive effects
- Hepatic enzyme inhibitors - may increase dimetindene levels