BRAND NAMES
 MECHANISM OF ACTION
Chlorpheniramine belongs to a group of medications known as first-generation antihistamines.
Chlorphenamine relieve allergic symptoms including runny nose, watery eyes and itchy skin. it is also indicated for the symptomatic relief of itch associated with chickenpox.
4 mg tablets:
- Adult: 1 tablet for every 4 to 6 hours, maximum 6 tablets (24mg) within 24 hours
- Elderly: 1 tablet for every 4 to 6 hours, maximum 3 tablets (12mg) within 24 hours
- Children (aged 6 to 12 years): half a tablet for every 4 to 6 hours within 24 hours, maximum 6 half tablets (12mg) within 24 hours.
Patients who are hypersensitive to antihistamines.
The anticholinergic properties of chlorphenamine are intensified by monoamine oxidase inhibitors (MAOIs) and therefore is contraindicated in patients who have been treated with MAOIs within the last fourteen days.
 WARNINGS AND PRECAUTIONS
Chlorphenamine, in common with other drugs having anticholinergic effects, should be used with caution in epilepsy; raised intra-ocular pressure including glaucoma; prostatic hypertrophy; severe hypertension or cardiovascular disease; bronchitis, bronchiectasis or asthma; hepatic impairment. Children and the elderly are more likely to experience the neurological anticholinergic effects and paradoxical excitation (eg. increased energy, restlessness, nervousness)
The effects of alcohol may be increased and therefore concurrent use should be avoided
Should not be used with other antihistamine containing products, including antihistamine containing cough and cold medicines
The anticholinergic properties of chlorphenamine may cause drowsiness, dizziness, blurred vision and psychomotor impairment, which can seriously hamper the patients' ability to drive and use machinery.
Concurrent use of chlorphenamine and hypnotics or anxiolytics may cause an increase in sedative effects, therefore medical advice should be sought before taking chlorphenamine concurrently with these medicines.
Chlorphenamine inhibits phenytoin metabolism and can lead to phenytoin toxicity.
The anticholinergic effects of chlorphenamine are intensified by MAOIs.
 PREGNANCY AND LACTATION
Pregnancy: Not to be used during pregnancy unless considered essentially by a physician.
Lactation: Chlorphenamine may inhibit lactation and may be secreted in breast milk. Not to be used during lactation unless considered essential by a physician
 SIDE EFFECTS
Very common undesirable effects (occurring in ≥10% of subjects): sedation, somnolence
Common undesirable effects (occurring in ≥1% to <10% of subjects): disturbance in attention, abnormal coordination, dizziness, headache, blurred vision, nausea, dry mouth
 RELATED LINKS
|For systemic use||Bilastine • Cetirizine • Chlorphenamine • Cyproheptadine • Dexchlorpheniramine • Desloratadine • Dimetindene (Oral route) • Ebastine • Fexofenadine • Ketotifen (Oral route) • Levocetirizine • Loratadine • Mequitazine • Mizolastine • Oxatomide (Oral route) • Rupatadine|
|For topical use||Dexchlorpheniramine (Topical) • Diphenhydramine • Dimetindene (Topical) • Oxatomide (Topical) • Promethazine|
|Nasal spray||Azelastine (Nasal spray) • Levocabastine (Nasal spray)|
|Eye drops||Azelastine (Eye drops) • Epinastine • Ketotifen (Eye drops) • Levocabastine (Eye drops) • Olopatadine (Eye drops)|
|Combinations||Cetirizine/Pseudoephedrine • Desloratadine/Pseudoephedrine|