Here is a collection of user reviews for the medication Toprol XL sorted by most helpful. See User Reviews. Report Problems to the Food and Drug Administration. You are encouraged to report negative side effects of prescription drugs to the FDA.
1 Persistent bad breath or a bad taste in the mouth can also be one of the warning signs of gum disease; which is caused by plaque.  Dry mouth. This occurs when the flow of saliva decreases and can be caused by various medications, salivary gland problems or continuously breathing through the mouth.
Bad breath can also be caused by dry mouth (known as xerostomia), which occurs when the flow of saliva decreases. Saliva cleanses the mouth and removes particles that may cause odor. Dry mouth is caused by various medications, salivary gland problems or continuously breathing through the mouth.here are many causes for breath odor. If you don't brush and floss every day, food stays in your mouth and collects bacteria, which can cause bad breath. Food collected between the teeth, on the tongue and around the gums can also rot, leaving an unpleasant odor.