Antifilarial

Diethylcarbamazine

Brand names: Hetrazan (specialist import)

Adult dose

Dose: 6mg/kg/day PO in divided doses for 12–21 days (per indication and weight-based titration)

Route: Oral

Frequency: OD–TDS

Clinical pearls

Lymphatic filariasis (Wuchereria bancrofti), Loa loa
WHO neglected tropical disease guidance
UKHSA imported infection / National Travel Health Network
Specialist tropical medicine prescribing; obtain via specialist import

Contraindications

Concurrent or untreated onchocerciasis (severe Mazzotti reaction; treat with ivermectin first)
Concurrent loiasis with high microfilarial load (encephalopathy risk)
Pregnancy
Hypersensitivity

Side effects

Mazzotti reaction (fever, rash, lymphadenopathy from microfilarial death)
Encephalopathy (loiasis)
Headache
GI upset

Interactions

Alcohol (Antabuse-like reaction)

Monitoring

Symptoms / CNS
Microfilarial load
FBC

Reference: BNF; WHO NTD guidelines; UKHSA imported infections; https://bnf.nice.org.uk/drugs/diethylcarbamazine/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Pathways