1. Clinical Overview
Diethylcarbamazine citrate is a synthetic piperazine derivative and the drug of choice for the treatment of lymphatic filariasis caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori. It is also effective against tropical pulmonary eosinophilia (TPE) and loiasis. It acts by altering the microfilarial surface membranes, making them susceptible to host immune system destruction. In India, it is a critical component of the National Filariasis Control Programme.
| Onset | Duration | Bioavailability |
|---|---|---|
| Rapid; microfilarial levels in blood drop significantly within 24-48 hours. | Approximately 12-24 hours; requires repeated dosing for full course. | Well absorbed (>85%) from the gastrointestinal tract. |
2. Mechanism of Action
Diethylcarbamazine (DEC) immobilizes microfilariae and alters their surface membranes, exposing them to phagocytosis by fixed tissue macrophages. It also impairs microfilarial muscular activity. Its action on adult worms is less clear but may involve disruption of intracellular processing and transport of proteins.
3. Indications & Uses
- Lymphatic Filariasis (Wuchereria bancrofti, Brugia malayi, Brugia timori)
- Tropical Pulmonary Eosinophilia (TPE)
4. Dosage & Administration
Adult Dosage: Filariasis: Day 1: 50 mg after meals, Day 2: 50 mg TID, Day 3: 100 mg TID, then 6 mg/kg/day in 3 divided doses for total 12 days. For MDA: Single dose of 6 mg/kg with Albendazole 400 mg.
Administration: Administer orally after meals to minimize GI upset. Tablets should be swallowed whole with a glass of water. For MDA, directly observed therapy (DOT) is recommended.
5. Side Effects
Common side effects may include:
- Nausea, vomiting, loss of appetite
- Headache, dizziness, drowsiness
- Weakness, malaise
- Mild fever, arthralgia
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Albendazole | Synergistic antifilarial effect; used together in MDA. | Moderate |
| Ivermectin | Increased risk of severe Mazzotti reaction in onchocerciasis; contraindicated. | High |
| CYP2D6 Inhibitors (e.g., Fluoxetine, Paroxetine) | May increase DEC plasma levels, increasing toxicity risk. | Moderate |
| Alcohol | May enhance CNS depressant effects like dizziness and drowsiness. | Moderate |
| Antihistamines | May be used to mitigate allergic reactions from DEC, but may mask early reaction signs. | Low |
7. Patient Counselling
- DO take the medicine after meals to reduce stomach upset.
- DO complete the full course of treatment as prescribed.
- DO inform your doctor if you are pregnant, planning pregnancy, or breastfeeding.
- DONT take this medicine if you have a known allergy to it.
- DONT consume alcohol during treatment.
8. Toxicology & Storage
Overdose: Nausea, vomiting, dizziness, headache, confusion, hypotension, and potentially seizures. Severe overdose may lead to respiratory depression.
Storage: Store below 30°C, protected from light and moisture. Keep out of reach of children.