My mother-in-law has been taking Bactrim since Thursday night to treat a urinary tract infection. Since then, she has been experiencing muscle pain, neck stiffness and headaches. Should she stop taking this antibiotic?

Hello, your mother should stop taking the medication and contact her pharmacist. In some cases, a 3-day course of this antibiotic can be effective in treating a urinary tract infection. The pharmacist can then advise if she should stop the antibiotic or switch to a different one.