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DERMATOLOGICALS › ANTIPRURITICS, INCL. ANTIHISTAMINES, ANESTHETICS, ETC. › ANTIPRURITICS, INCL. ANTIHISTAMINES, ANESTHETICS, ETC. › Antihistamines for topical use
thenalidine
D04AA03
Adult Dosing
- 20 mg orally 2 to 3 times daily
- Maximum daily dose: 60 mg
Pediatric Dosing
- Safety and efficacy in pediatric patients not established
- Use generally not recommended in children
Indications
- Symptomatic relief of pruritus
- Allergic skin conditions
- Urticaria
Mechanism of Action
- First-generation antihistamine acting as an inverse agonist or antagonist at histamine H1 receptors
- Possesses mild anticholinergic and sedative properties
Contraindications
- Hypersensitivity to thenalidine or other phenothiazine derivatives
- Concomitant use with monoamine oxidase inhibitors (MAOIs)
- Newborn or premature infants
- Conditions associated with significant CNS depression
Adverse Reactions
- Drowsiness and sedation
- Dry mouth, blurred vision, and urinary retention (anticholinergic effects)
- Dizziness and orthostatic hypotension
- Gastrointestinal upset
- Rarely: leukopenia or agranulocytosis associated with phenothiazine class
Drug Interactions
- Enhanced CNS depression with alcohol, barbiturates, opioids, and sedatives
- Potentiation of anticholinergic effects when combined with other anticholinergic agents
- Prolongation of adverse effects when taken with MAOIs
Curated Content: Needs Vetting Before Put to Clinical Use