Can antibiotics be used as painkillers? Bringing new drugs to the market is an expensive and complicated affair. New uses of old drugs can be extremely time-saving and cost-effective. Antibiotics are generally prescribed with pain-killers for many infective painful conditions. Having an antibiotic with some analgesic effects can help in reducing the dose of analgesics and thus, their side effects. It can help reduce pill-burden in a number of patients.