A variety of medications are responsible for creating the aggravating condition referred to as "dry mouth." Several classes of drugs are designed to work on general areas of the body, but unfortunately are not specific enough and affect other areas as well. These medications include psychiatric drugs, cold medicines, antidiarrheals, urinary incontinence medications, muscle relaxants, and drugs for Parkinson's disease.
Cold and Flu Medications
Some decongestants and antihistamines, which relieve nasal and throat congestion, contain what is known as an anticholinergic. According to the International Society for Complexity, Information, and Design, or ISCID, an increase in acetylcholine, a neurotransmitter found in your body, decreases heart rate, increases your saliva production, and stimulates muscle activity. Anticholinergics work by blocking the effects of acetylcholine. The result is an increase in heart rate, a decrease in saliva production, and a reduction in muscle activity. Thus, you end up with a dry mouth.
Urinary Incontinence
You are probably wondering how a medication for urinary incontinence can cause you to have a dry mouth. Simply put, anticholinergics are used for urinary incontinence. If you remember, acetylcholine stimulates muscle activity. When the muscles in the bladder are stimulated, you feel the urge to urinate. According to the Mayo Clinic, if you suffer from urinary incontinence, you most likely have overactive bladder muscle activity. One of the jobs of an anticholinergic is to block this muscle activity, which, in turn, reduces the urge to urinate. So while an anticholinergic is keeping you out of the bathroom, it is also the medication causing your dry mouth.
Antidepressants
Dry mouth is the most common adverse reaction that you will have when taking an anticholinergic drug. Some medications are not pure anticholinergics but produce anticholinergic effects. Many antidepressants are included in this list; Dexmethylphenidate, for example, only causes a reduction in saliva without the decrease in heart rate and muscle stimulation. Duloxetine, on the other hand, causes dry mouth, urinary hesitation and constipation. No matter which medications are causing the discomfort, you can control your dry mouth by sucking on a piece of candy, preferably sugar free, and sipping water regularly.
