Diethylcarbamazine Citrate

Approved Indications:

• Lymphatic Filariasis (Wuchereria bancrofti, Brugia malayi, Brugia timori)
• Treatment and eradication of microfilariae and adult worms to reduce disease progression
• Loiasis (Loa loa infection)
• Clearance of microfilariae from blood and management of symptoms
• Mansonellosis (Mansonella streptocerca, Mansonella perstans)
• Reduction of microfilaremia in endemic areas
• Tropical Pulmonary Eosinophilia
• Adjunct treatment to reduce eosinophilic lung inflammation caused by filarial infections

Off-label/Clinically Accepted Uses:

• Occasional use in combination therapy for other filarial infections as guided by local protocols
• May be used in mass drug administration (MDA) campaigns for filariasis elimination programs

Route: Oral

Adults:

• Typical dose: 6 mg/kg/day divided into 2 or 3 doses daily
• Duration: 12 days for lymphatic filariasis or loiasis treatment
• Maximum dose generally should not exceed 300 mg/day

Children:

• Dose: 6 mg/kg/day divided into 2 or 3 doses daily
• Duration and total dose adjusted according to body weight and clinical response
• Tablets can be crushed and mixed with water for easier administration

Elderly:

• No specific dose adjustment required, but monitor closely for adverse effects

Renal/Hepatic Impairment:

• Use with caution in renal or hepatic dysfunction; dose adjustment may be needed
• Close monitoring advised due to risk of accumulation and toxicity

Diethylcarbamazine citrate acts primarily by altering the surface membrane of microfilariae and adult filarial worms, increasing their susceptibility to host immune attack. It affects arachidonic acid metabolism in microfilariae, disrupting microtubule function and inhibiting motility. DEC also enhances the host’s immune response, facilitating phagocytosis and clearance of the parasites. The drug’s precise mechanism is multifactorial but results in rapid immobilization and death of microfilariae and reduction of adult worm viability.

• Absorption: Rapidly and almost completely absorbed from the gastrointestinal tract after oral administration
• Peak Plasma Concentration: Within 1–2 hours
• Bioavailability: Approximately 90%
• Distribution: Widely distributed throughout body tissues including lungs, liver, and lymphatics
• Metabolism: Minimally metabolized; primarily excreted unchanged
• Half-life: Approximately 6–12 hours
• Elimination: Mainly renal excretion (up to 90% unchanged in urine)
• Onset of Action: Clinical effect usually seen within days of starting treatment

• Pregnancy:
• FDA Category C — Risk cannot be ruled out; use only if potential benefits justify potential risk to fetus
• Animal studies have shown some adverse effects; human data limited
• Lactation:
• Excretion into breast milk is minimal but not well-studied
• Caution advised; weigh benefits of therapy against potential risks to infant

• Primary Class: Antifilarial agent
• Subclass: Piperazine derivative

• Known hypersensitivity to diethylcarbamazine or any formulation excipients
• Patients with onchocerciasis (risk of severe inflammatory reactions) unless used under specialist supervision
• Severe hepatic or renal impairment without careful monitoring
• Use contraindicated in presence of severe active infections that might be worsened by immune responses

• Mazzotti Reaction: May cause fever, rash, lymphadenitis, hypotension, and other inflammatory reactions due to parasite death, especially in heavy infections
• Neurological Effects: Possible encephalopathy in heavy Loa loa infections; monitor closely
• Renal and Hepatic Impairment: Adjust dose and monitor for toxicity
• Hypersensitivity Reactions: Anaphylaxis and severe allergic reactions possible
• Pregnancy & Lactation: Use only if clearly needed
• Avoid in Onchocerciasis unless under expert supervision due to risk of severe ocular and systemic inflammatory reactions

Common:

• Headache
• Dizziness
• Nausea and vomiting
• Abdominal discomfort
• Fever and malaise (Mazzotti reaction)
• Fatigue

Serious/Rare:

• Hypotension
• Severe allergic reactions (rash, urticaria, anaphylaxis)
• Neurological complications (encephalopathy in heavy Loa loa infections)
• Visual disturbances

• No major documented drug interactions, but caution when used with:
• Other antiparasitic agents that may increase risk of inflammatory reactions
• Immunosuppressants may alter drug efficacy or reaction severity
• No significant CYP450 enzyme involvement reported

• WHO recommends DEC as part of mass drug administration programs combined with albendazole for lymphatic filariasis elimination
• Updated guidelines emphasize screening for onchocerciasis before DEC use to prevent severe adverse effects
• Dose adjustments and caution advised in Loa loa endemic areas due to encephalopathy risk
• New research ongoing into combination therapies for improved efficacy and safety

• Store at controlled room temperature: 20°C to 25°C (68°F to 77°F)
• Protect from moisture and light
• Keep tablets in original packaging until use
• Keep out of reach of children