Antipiroplasmal drugs:

• These are the agents which are active against three disease of animal; babesiosis, theileriosis and cytauxzoonosis.

Classification:

Diamidines:

Imidocarb:

• It is antiprotozoal agent of carbanilide series.
• It is used in treatment of babesiosis, anaplasmosis, and ehrlichiosis.
• Available in hydrochloride or dipropionate salt.

Mechanism of action:

• Mode of action is uncertain, but two mechanisms are proposed:
• First, it is proposed that it interferes with production or utilization of polyamines. Polyamines are polycations that interact with negatively charged molecules such as DNA, RNA, and proteins. They play multiple roles in cell growth, survival, and cell proliferation.
• Second, it prevents the entry of inositol into the erythrocyte containing parasite. Inositol is required for RBC integrity.

Antiprotozoal spectrum:

• Active against babesia, cytauxzoon, hepatozoon and Anaplasma species.
• Effective against B.canis and B.gibsoni in dogs and B. cabadi in horses.
• Donot interfere with formation of immunity in treated animals.

Pharmacokinetics:

• They are poorly absorbed after oral administration, so given through parenteral route.
• After parenteral administration, it is distributed widely throughout the body.
• Highly bound to plasma proteins.
• Excreted largely unchanged in urine (~ 90%) and faeces (10%).
• As it is highly bound to plasma proteins and accumulation of drug in tissues, one injection is sufficient for antiprotozoal activity for several weeks (>4 weeks).

Side effects/ Adverse effects:

• Low therapeutic index
• Vomiting in dogs
• Signs of cholinergic action like salivation, lethargy, lachrymation, ataxia, tremors, convulsions
• Restlessness, diarrhoea, panting
• Pain and inflammation at site of injection
• In cattle, dose of 10 mg/kg can cause death.

Contraindications and precautions:

• In patients with hepatic or renal abnormalities
• In food producing animals
• In pregnant animals, lactating and pediatric patients.
• It must not be administered by IV route.

Indications:

• In treatment of intracellular tick-borne pathogens
• In treatment or prophylaxis of babesiosis in cattle, sheep, horses, and dogs.
• Also used in treatment of anaplasmosis in cattle and ehrlichiosis in dogs.

Doses:

For babesiosis:

Dogs: 5 mg/kg, IM, or SC, once. Dose may be repeated after 2 weeks.

Cattle: 1.2 mg/kg, SC, single dose