HETRAZAN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for HETRAZAN (HETRAZAN).
Diethylcarbamazine (HETRAZAN) sensitizes microfilariae to phagocytosis by immobilizing them and altering their surface, making them more susceptible to destruction by host immune cells. It also has anthelminthic activity against adult worms.
| Metabolism | Diethylcarbamazine is rapidly absorbed and extensively metabolized in the liver via N-oxidation and N-demethylation, involving multiple CYP enzymes. The major metabolite is diethylcarbamazine N-oxide. |
| Excretion | Renal excretion of unchanged drug accounts for approximately 50-60% of elimination; the remainder is metabolized hepatically with metabolites excreted in urine. Fecal elimination is minimal (<5%). |
| Half-life | Terminal elimination half-life is 8-12 hours in patients with normal renal function; may be prolonged in renal impairment. |
| Protein binding | Protein binding is approximately 10-20%, primarily to albumin. |
| Volume of Distribution | Volume of distribution is 1.5-2.5 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral bioavailability is approximately 90% due to well absorption from the gastrointestinal tract. |
| Onset of Action | Oral: Onset of action occurs within 1-2 hours after administration for microfilaricidal effect. |
| Duration of Action | Duration of action is approximately 12-24 hours following a single oral dose; repeat doses are needed for sustained effect in filarial infections. |
| Molecular Weight | 391.5 |
| Action Class | Antiprotozoal agents |
| Brand Substitutes | Banocide 120mg Syrup, Deecee 120mg Syrup, Decee Syrup, Deecee AD 120mg Syrup |
2 mg/kg orally three times daily after meals for 3 weeks (total dose 120 mg/kg per course). Maximum single dose: 10 mg/kg.
| Dosage form | TABLET |
| Renal impairment | No specific GFR-based dose modifications available; use with caution in renal impairment due to potential accumulation. Monitor for adverse effects. |
| Liver impairment | Child-Pugh A: No adjustment needed. Child-Pugh B: Reduce dose by 50%. Child-Pugh C: Contraindicated. |
| Pediatric use | 2 mg/kg orally three times daily after meals for 3 weeks (total dose 120 mg/kg per course). Maximum single dose: 10 mg/kg. For children <15 kg, dosage based on 1 mg/kg initially, then increase gradually. |
| Geriatric use | Initiate at lower end of dosing range (2 mg/kg per dose) due to potential age-related decrease in renal function. Monitor closely for adverse effects. |
| 1st trimester | No adequate studies in pregnant women. Animal studies are insufficient. Use only if clearly needed and potential benefit justifies risk. |
| 2nd trimester | No adequate studies in pregnant women. Use only if clearly needed. |
| 3rd trimester | No adequate studies in pregnant women. Use only if clearly needed. |
Clinical note
Comprehensive clinical and safety monograph for HETRAZAN (HETRAZAN).
| Placental transfer | Unknown; likely crosses placenta due to low molecular weight. |
| Breastfeeding | Excreted into human milk in small amounts. Caution is advised; consider risk vs benefit. |
| Lactation Rating |
■ FDA Black Box Warning
HETRAZAN is contraindicated in patients with onchocerciasis (river blindness) due to the risk of severe Mazzotti reaction, including ocular damage and encephalopathy. Treatment should not be initiated in areas where onchocerciasis is endemic or in patients with suspected onchocerciasis.
| Serious Effects |
Hypersensitivity to diethylcarbamazinePre-existing severe renal or hepatic impairment
| Precautions | Severe allergic or inflammatory reactions (Mazzotti reaction) in patients with onchocerciasis; encephalopathy in loiasis with high microfilarial loads; ocular damage (e.g., uveitis, optic neuritis) in onchocerciasis; thrombocytopenia; aminotransferase elevations; use in pregnancy only if clearly needed. |
| Food/Dietary | Grapefruit juice may inhibit CYP450 metabolism; avoid concurrent intake. Administer with food to reduce gastrointestinal distress. |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | Animal studies have not been conducted; no adequate human data. Use only if benefit outweighs risk. No known teratogenic effects in first trimester; limited data in second and third trimesters. |
| Fetal Monitoring | Monitor for maternal hypersensitivity reactions, hepatotoxicity, and renal function. No specific fetal monitoring required. |
| Fertility Effects | No known effects on fertility in animal studies. Human data lacking. |
| Clinical Pearls | HETRAZAN (diethylcarbamazine) is primarily used for lymphatic filariasis and loiasis; monitor for Mazzotti reaction (fever, rash, arthralgias) in high microfilarial loads; contraindicated in onchocerciasis due to severe ocular reactions; administer with food to reduce GI upset. |
| Patient Advice | Take with food to minimize nausea. · Report any severe itching, rash, fever, or vision changes. · Complete full course even if symptoms improve. · Avoid grapefruit juice which may affect metabolism. · May cause dizziness or drowsiness; avoid driving if affected. |