 The adverse effects of long @-@ term linezolid therapy were first identified during postmarketing surveillance . Bone marrow suppression was not identified during Phase III trials , in which treatment did not exceed 21 days . Although some participants of early trials did experience thrombocytopenia , it was found to be reversible and did not occur significantly more frequently than in controls ( participants not taking linezolid ) . There have also been postmarketing reports of seizures , and , as of 2009 , a single case each of Bell 's palsy ( paralysis of the facial nerve ) and kidney toxicity . 
