A fixed-dose combination (FDC) medication used primarily for the treatment of lymphatic filariasis (elephantiasis) and associated allergic manifestations. Diethylcarbamazine (DEC) is an anthelmintic and antiparasitic agent effective against microfilariae and adult worms of Wuchereria bancrofti and Brugia malayi. Levocetirizine is a potent, selective second-generation H1-receptor antagonist (antihistamine) that alleviates allergic symptoms like pruritus, urticaria, and angioedema often associated with filarial infections. This combination addresses both the parasitic cause and the inflammatory/allergic symptoms.
Adult: One tablet (Diethylcarbamazine 300mg + Levocetirizine 5mg) once daily after meals. For filariasis: Typically prescribed for 7-21 days as per physician's advice.
Note: Take after food to minimize gastrointestinal upset. Swallow whole with a glass of water. Do not crush or chew. Evening administration may help with compliance and manage nocturnal symptoms. Complete the full course as prescribed.
Diethylcarbamazine immobilizes microfilariae by altering their surface membranes, making them susceptible to host phagocytosis. It also damages adult worms. Its mechanism may involve inhibition of arachidonic acid metabolism in parasites. Levocetirizine competitively inhibits histamine at the H1 receptor, preventing capillary dilation, bronchoconstriction, and pruritus associated with histamine release during filarial antigen exposure (Mazzotti-like reaction).
Pregnancy: Category C (US FDA). Animal studies show risk. DEC and levocetirizine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, especially in active filarial disease. Consult specialist.
Driving: May impair ability to drive or operate machinery. Patients should not engage in these activities until they know how the medication affects them, especially during initial treatment.
| CNS Depressants (Alcohol, Benzodiazepines, Opioids) | Additive sedative effect with levocetirizine. | Major |
| Theophylline | May reduce the clearance of levocetirizine slightly. | Moderate |
| Ritonavir | May increase levocetirizine levels. | Moderate |
| Drugs causing QT prolongation (e.g., Erythromycin, antipsychotics) | Theoretical additive risk of QT prolongation. | Moderate |
| Nephrotoxic drugs (Aminoglycosides, NSAIDs) | May worsen renal function, affecting levocetirizine excretion. | Moderate |
Same composition (Diethylcarbamazine (300mg) + Levocetirizine (5mg)), different brands: