IMIDAZOTHIAZOLES:

 Toxicokinetics: These agents exhibit good oral absorption.

 Mechanism of Action:

 Levamisole has a structural and functional similarity to nicotine.

Levamisole acts by producing a sustained depolarization of the nematode muscle membrane and blockade of the neuromuscular junction.

Intoxication can result in muscarinic and nicotinic effects.

Clinical Signs: In sheep and pigs, the most common syndrome of levamisole intoxication produced nausea, vomiting, hypersalivation, frequent urination and defecation, muscle tremors, ataxia, anxiety, convulsions, depression, dyspnea, prostration, and death.

In dogs, toxicosis elicits vomiting, bradycardia, tachypnea, hypothermia, cerebrocortical depression, and diarrhea.

Lesions: Lesions are not specific to levamisole intoxication but may be related to terminal convulsions. Lesions include cardiac and thalamic hemorrhages, enteritis, hepatic degeneration, necrosis, and splenic congestion.

Treatment: No antidote is available. Supportive and symptomatic therapy are indicated in poisoned patients. Atropine may be beneficial in controlling some of the cholinergic signs.

Prognosis: Animals that survive or can be supported during the acute phase of intoxication have a good chance of complete recovery.