The number of patients who reported an adverse effect last year while taking Questcor's (QCOR) Acthar drug amounted to almost 5% of prescriptions dispensed, the company stated in a regulatory filing released yesterday, according to The New York Times. The filing marked the first time that the company has disclosed any difficulties experienced by Acthar patients, the newspaper added. Questcor has agreed to be bought by Mallinckrodt (MNK).