Many drugs cause dry mouth, or xerostomia. According to pharmacologist Mohammed Abdollahi and colleagues in a 2008 article for the "Journal of Contemporary Dental Practice," some drugs decrease the flow of saliva or concentration of calcium and phosphorus, causing dry mouth. They note most drug reactions are noticeable within two weeks of starting a medication. If a dry mouth is noted a month later, it probably wasn't drug-induced. Many elderly people suffer from dry mouth, according to medical school professors Michael D. Turner and Jonathan A. Ship in a 2007 article for the "Journal of the American Dental Association." They say older people are more likely to take prescribed drugs and are more vulnerable to side effects. Turner and Ship note two medications are FDA-approved for dry mouth: pilocarpine and cevimeline. Mouthwashes and sugar-free gums and mints also help.
According to Abdollahi and colleagues, many psychiatric medicatons cause dry mouth, including benzodiazepines -- drugs to treat anxiety disorders -- as well as antipsychotics. In addition, antidepressants may also cause xerostomia, such as selective serotonin reuptake inhibitors -- SSRIs -- as well as tricyclic antidepressants and the atypical antidepressant bupropion. Lithium used to treat bipolar disorder may also cause dry mouth.
Turner and Ship note that sometimes a type of medication is needed and a drug causing a less severe side effect may be chosen. For example, they report SSRIs are less likely to cause xerostomia than tricyclic antidepressants.
Some drugs used to treat hypertension may cause dry mouth, according to Abdollahi and colleagues, particularly beta blockers and calcium channel blockers. Turner and Ship also note other antihypertensive drugs may cause dry mouth, such as alpha blockers, angiotensin-converting enzyme inhibitors -- ACEIs -- and diuretics.
The use of some illegal drugs can cause dry mouth, according to "A Guide to Substance Abuse for Medical Professionals," compiled by Irish drug education officer Sinead O'Mahony Carey. She reports that heroin causes dry mouth -- as well as many other side effects, such as slowed heart rate, itchy skin and painful withdrawal from the drug. She also notes abused drugs such as cocaine and amphetamines may cause dry mouth. In addition, methylenedioxymethamphetamine -- also known as MDMA or Ecstasy -- leads to a very dry mouth as well as a sore throat.
Urinary Incontinence Drugs
Karl-Erik Andersson, M.D., and colleagues report in "UroToday International Journal" in 2009 that some drugs given to treat urinary incontinence caused by nerve overactivity can cause dry mouth, particularly darifenacin, fesoterodine and oxybutynin oral extended release. In addition, oxybutynin transdermal patches and solifenacin ER, tolterodine ER and trosium chloride ER can cause dry mouth.