Vetdrugs 2.0Diethylcarbamazine is an older anthelmintic best known for its historical daily use in canine heartworm prevention. It acts against early developing stages of Dirofilaria immitis and has also been used at different regimens for ascarid infections. Its veterinary use has greatly diminished with the availability of longer-acting preventive products.
Group
Piperazine anthelmintic
Mechanism of Action
The mechanism of diethylcarbamazine is incompletely defined and includes parasite-directed and host-dependent effects. Proposed actions include altered parasite neuromuscular function and modification of arachidonic-acid signaling in filarial parasites and host tissues. Experimental filarial studies support enhanced immobilization and immune-mediated clearance of susceptible larvae or microfilariae. These mechanisms are not fully established for each veterinary parasite or life stage.
Dose Rates
Dog
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Heartworm prevention | 6.6 mg/kg | PO | Every 24 h | Do not use in: Established heartworm infection or microfilaremia; Historical daily citrate regimen. |
| Ascarids | 55–110 mg/kg | PO | Once | Do not use in: Established heartworm infection or microfilaremia; The 110 mg/kg total may be split into two doses in dogs. Consider retreatment after 10–20 days in cats. |
| Heartworm prevention | 2.5–3 mg/kg | PO | Every 24 h | Do not use in: Microfilaremia; Alternative historical regimen; screen for microfilariae before initiation. |
| Heartworm prevention | 5–7 mg/kg | PO | Every 24 h | Do not use in: Microfilaremia; Start before exposure and continue 60 days after mosquito season. |
| Lungworm treatment | 80 mg/kg | PO | Every 12 h | Up to 3 days; Do not use in: Microfilaremia; Crenosoma vulpis. |
Cat
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Ascarids | 55–110 mg/kg | PO | Once | Do not use in: Established heartworm infection or microfilaremia; The 110 mg/kg total may be split into two doses in dogs. Consider retreatment after 10–20 days in cats. |
Ferret
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Heartworm prevention | 5.5 mg/kg | PO | Every 24 h |
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Early dictyocaulosis | 22 mg/kg | IM | Every 24 h | Up to 3 days |
| Early dictyocaulosis | 44 mg/kg | IM | Once |
Indications
- Historical daily prevention of canine heartworm infection by targeting early Dirofilaria immitis larvae.
- Historical treatment of susceptible ascarid infections in dogs, including Toxocara canis and Toxascaris leonina.
- Historical treatment of susceptible ascarid infections in cats using a corresponding anthelmintic regimen.
Contraindications
- Established heartworm infection or microfilaremia before appropriate adulticidal and microfilaricidal treatment
Adverse effects
- Vomiting
- Potential severe reactions in microfilaremic dogs
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Diethylcarbamazine citrate 30 mg | Tablet | 30 mg / tablet | PO |
| Diethylcarbamazine citrate 45 mg | Tablet | 45 mg / tablet | PO |
| Diethylcarbamazine citrate 50 mg | Tablet | 50 mg / tablet | PO |
| Diethylcarbamazine citrate 60 mg | Tablet | 60 mg / tablet | PO |
| Diethylcarbamazine citrate 100 mg | Tablet | 100 mg / tablet | PO |
| Diethylcarbamazine citrate 120 mg | Tablet | 120 mg / tablet | PO |
| Diethylcarbamazine citrate 150 mg | Tablet | 150 mg / tablet | PO |
| Diethylcarbamazine citrate 180 mg | Tablet | 180 mg / tablet | PO |
| Diethylcarbamazine citrate 200 mg | Tablet | 200 mg / tablet | PO |
| Diethylcarbamazine citrate 300 mg | Tablet | 300 mg / tablet | PO |
| Diethylcarbamazine citrate 400 mg | Tablet | 400 mg / tablet | PO |
| Diethylcarbamazine citrate syrup 60 mg/mL Source-described presentation; current local availability unverified. | Oral Liquid | 60 mg / mL | PO |
| Diethylcarbamazine citrate injection 400 mg/mL Historical injectable presentation described in the supplied material; current availability unconfirmed. | Injection | 400 mg / mL | IM |
Monitoring and Administration
Test heartworm and microfilarial status before use. Daily adherence is essential for the historical prevention regimen; alternatives have largely replaced it.
Food may reduce vomiting. Repeat ascarid treatment after 10–20 days when needed.