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) and tropical pulmonary eosinophilia. It is also effective against loiasis (Loa loa) and is used in mass drug administration (MDA) programs in India under the National Filariasis Elimination Programme. It acts primarily by altering the microfilarial surface membranes, making them susceptible to host immune system destruction.
| Onset | Duration | Bioavailability |
|---|---|---|
| Rapid; microfilarial levels in blood drop within hours. | Approximately 12-24 hours; requires repeated dosing for full therapeutic course. | Well absorbed (>85%) from the gastrointestinal tract. |
2. Mechanism of Action
The precise mechanism is not fully elucidated. It is believed to act by: 1) Immobilizing microfilariae by altering their surface membranes, making them more susceptible to phagocytosis by fixed tissue macrophages. 2) Possibly interfering with arachidonic acid metabolism in microfilariae. 3) Modifying host immune responses, enhancing adherence of granulocytes to microfilariae. It has minimal direct effect on adult worms (macrofilariae) but may impair their production of microfilariae.
3. Indications & Uses
- Lymphatic Filariasis (Bancroftian and Brugian)
- Tropical Pulmonary Eosinophilia (TPE)
4. Dosage & Administration
Adult Dosage: Filariasis: Day 1: 50mg after meals, Day 2: 50mg three times, Day 3: 100mg three times, then 6mg/kg/day in three divided doses for total 12 days. MDA (with Albendazole): Single dose of 6mg/kg (approx 300-400mg) annually. TPE: 6mg/kg/day in three divided doses for 14-21 days.
Administration: Administer with or immediately after meals to reduce gastrointestinal upset. Tablets should be swallowed whole with a full glass of water. For MDA programs, directly observed therapy (DOT) is recommended.
5. Side Effects
Common side effects may include:
- Nausea
- Vomiting
- Headache
- Dizziness
- Loss of appetite
- Mild fever
- Malaise
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Albendazole | Synergistic antifilarial effect; used together in MDA. No significant PK interaction. | Moderate |
| Corticosteroids (e.g., Prednisolone) | May be used prophylactically to attenuate Mazzotti reactions. No direct interaction. | Minor |
| Drugs that alkalinize urine (e.g., Sodium Bicarbonate, Acetazolamide) | Decreases renal excretion, increases plasma levels and half-life, raising toxicity risk. | Major |
| Drugs that acidify urine (e.g., Ammonium Chloride, Ascorbic Acid high dose) | Increases renal excretion, may reduce efficacy. | Moderate |
| CNS depressants (Alcohol, Benzodiazepines) | Additive sedative effect with dizziness. | Moderate |
7. Patient Counselling
- DO take the medicine exactly as prescribed, with food.
- DO complete the full course of treatment even if you feel better.
- DO inform your doctor if you are pregnant, planning pregnancy, or breastfeeding.
- DONT skip doses.
- DONT take antacids or other drugs that make urine alkaline without consulting your doctor.
- DONT consume alcohol during treatment.
8. Toxicology & Storage
Overdose: Nausea, vomiting, dizziness, headache, hypotension, and confusion. Severe overdose could lead to CNS depression, convulsions, or cardiorespiratory collapse.
Storage: Store below 30°C in a cool, dry place, protected from light and moisture. Keep out of reach of children.