Renal effects primidone

With chronic exposure, side effects may include rash, thrombocytopenia, leukopenia, and a lupus-like disorder. Chronic therapy is likely to result in tolerance, and withdrawal symptoms if primidone therapy is abruptly stopped. Doses in excess of 1500 mg (twice the maximum recommended daily dose) should be considered toxic. Less common side effects are hypotension, hypothermia, and dermal bullae. Encephalopathy has been observed in an epileptic patient with high plasma levels and poor renal function. With plasma concentrations exceeding 80pgml primidone may precipitate and cause crystalluria. Plasma levels >10 rgpml are associated with toxic effects. The therapeutic range is reportedly 5-10pgml , but clinical effects correlate more closely with phenobarbital blood levels. 

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