A fixed-dose combination of an anthelmintic (Diethylcarbamazine) and a first-generation antihistamine (Chlorpheniramine Maleate). Primarily used for the treatment and prophylaxis of lymphatic filariasis (caused by Wuchereria bancrofti and Brugia malayi) and tropical pulmonary eosinophilia. The combination is particularly effective in the Indian context for mass drug administration (MDA) programs and individual treatment. Chlorpheniramine helps mitigate the acute inflammatory reactions (Mazzotti-type reactions) commonly seen with Diethylcarbamazine therapy.
Adult: For Filariasis: 150mg DEC + 2.5mg Chlorpheniramine as a single dose. Often repeated annually in MDA. For TPE: 150mg DEC + 2.5mg Chlorpheniramine three times daily for 14-21 days.
Note: Administer after meals to minimize GI upset. Tablet should be swallowed whole with a full glass of water. For MDA programs, administration is directly observed.
Diethylcarbamazine (DEC) immobilizes microfilariae by altering their surface membranes, making them susceptible to host phagocytosis by the reticuloendothelial system. It also damages adult worms, impairing their muscular activity and metabolism. Chlorpheniramine Maleate is a competitive reversible H1-receptor antagonist. It blocks the effects of histamine released during the inflammatory response to dying parasites, thereby reducing symptoms like itching, rash, fever, and malaise.
Pregnancy: Category C (US FDA). DEC: Animal studies show risk, human data limited. Chlorpheniramine: Category B. Avoid in first trimester. Use only if potential benefit justifies potential fetal risk, especially in endemic areas for filariasis. Not recommended for routine MDA in pregnant women.
Driving: NOT ADVISABLE. Chlorpheniramine causes significant drowsiness and can impair cognitive and motor skills. Patients should not drive or operate heavy machinery for at least 8-12 hours after dosing.
| Alcohol and other CNS Depressants (Benzodiazepines, Opioids) | Additive CNS depression and impaired psychomotor performance. | Major |
| Monoamine Oxidase Inhibitors (MAOIs) e.g., Phenelzine | Increased anticholinergic and CNS effects of Chlorpheniramine; risk of hypertensive crisis. | Contraindicated |
| Other Anticholinergics (Atropine, Tricyclic Antidepressants) | Enhanced anticholinergic side effects (dry mouth, urinary retention, confusion). | Major |
| Hepatic Enzyme Inducers (Phenobarbital, Rifampicin) | May reduce plasma levels of both components. | Moderate |
| Hepatic Enzyme Inhibitors (Cimetidine, Ketoconazole) | May increase plasma levels of both components, increasing toxicity risk. | Moderate |
Same composition (Diethylcarbamazine (150mg) + Chlorpheniramine Maleate (2.5mg)), different brands: