Changes

==Side Effects and Contraindications==

==Side Effects and Contraindications==

Most adverse effects and side effects are the same as those listed for phenobarbital; however, primidone administration may be associated with a higher incidence of hepatotoxicity. Hepatic necrosis, fibrosis and cirrhosis have been associated with chronic use of primidone. Intrahepatic cholestasis has occured in dogs in which primisone was combined with phenytoin.

Since a large proportion of primidone is converted to phenobarbital, most adverse and side affects are the same as for this drug. These may include polyphagia, polyuria and polydipsia, which are usually transient and disappear with time. A sedative effect may also be seen. Additional side effects of primidone are nausea, drowsiness, ataxia, nystagmus and, rarely, dermatitis. In many, megaloblastic anaemia may develop from primidone use, and so the drug should be stored securely out of the reacch of children.

manufacturers do nor recommed its used in cats; in fact it is stated on the package inerst that its use should be cautioned in cats. However, studies in cats have demonstrated that primidone is probably safe.

Occasionally polyphagia, polyuria and polydipsia have been reported, but these effects are usually transitory and disappear with continued medication.

Primidone is associated with a higher incidence of hepatotoxicity than phenobarbital: hepatic necrosis, fibrosis and cirrhosis have all been associated with chronic use of primidone. One study reported that up to 14 in 20 dogs develop liver toxicity following primidone administration. It is therefore important that liver enzyme assays and tests of liver function are regularly performed to monitor toxicity when primidone is prescribed to veterinary patients.

identical sedative side effects are seen in the dog after treatment with phenobarbital and after treatment with primidone. Primidone will cause all of the side effects noted for phenobarbital. primidone may induce nystagmus, nausea, drowsiness and ataxia. PD is more common in dogs treated with primisone. In man, megaloblastic anaemia is a side effect of primidone. In the dog, primidone induces progressive hepatic injury as manifested by increases in liver enzyme values. In a clinica study, signs of lover toxicity were repoerted in 14 of 20 dofs. Hepatic cirrhosis associated wth primidone and phenobarbital after 7 years of use has been reported in a dog. Dermatitis is a rarely reported side effect.

Primidone should bot be used in combination with chloramphenicol, as chloramphenicol is a potent inhibioty of microsomal enzymes and so may lead to primidone toxicity. signs include severe central nervous system depression, and inappetance. Primidone has also been reported to cause intrahepatic cholestasis when used in combination with phenytoin.  

Should not be used with chloramphenicol - potent inhibotr of the microsomal enzyme system: sever CNS deression and inappetance.

Manufacturers do not recommed the use of primidone in cats, although studies have suggested that primidone is probably safe in this species.

==References==

==References==