Chlorphenamine

Products

Chlorphenamine is commercially available as a monopreparation (Arbid N drops) and as a combination preparation (e.g., Fluimucil Flu Day & Night, Solmucalm, Triocaps). The enantiomer dexchlorpheniramine was formerly available in tablet form. Rhinopront is out of commerce.

Structure and properties

Chlorphenamine (C₁₆H₁₉ClN₂, M_r = 274.79 g/mol) is a chlorinated pheniramine and is also known as chloropheniramine. It is racemic. The enantiomer dexchlorpheniramine was also commercially available as a drug. It is present in drugs as chlorphenamine maleate, a white crystalline powder that is readily soluble in water.

Effects

Chlorphenamine (ATC R06AB04) has antihistamine, antiallergic, sedative, desiccant, and anticholinergic effects during 4 to 6 hours.

Indications

Inflammatory and allergic diseases of the upper respiratory tract such as rhinitis, hay fever, chronic nasal runny nose, vasomotor or allergic rhinitis, rhinopharyngitis, allergic sinusitis.
For flu and colds.
For symptomatic treatment of allergic conditions such as hives and conjunctivitis.

Contraindications

Hypersensitivity
Narrow-angle glaucoma
Bladder emptying disorders, such as advanced prostate enlargement.
Acute asthma attack
Concurrent or previous treatment with an MAO inhibitor.
Pheochromocytoma
Pregnancy and lactation
Infants

For complete precautions and information on interactions, see the drug label.

Interactions

Other centrally depressant agents may potentiate the sedative effects of chlorphenamine. These include, for example, alcohol, antidepressants, benzodiazepines, or neuroleptics. Other interactions are possible with phenytoin, MAO inhibitors (hypertensive crisis), betahistine, glucocorticoids, and other antichloinergics.

Adverse effects

Possible adverse effects include fatigue; drowsiness; poor concentration; dry mouth, nose, and throat; visual disturbances; glaucoma triggering; urinary retention; nervousness; sleep disturbances. Chlorphenamine may cause drowsiness and reduce alertness. Therefore, driving and operating machinery should be avoided.