Medications That Cause Dry Mouth
Dry mouth is a common problem in many people, especially the elderly and women. Dry mouth which is otherwise medically termed as "xerostomia" usually results from salivary gland hypofunction which can lead to low salivary flow rates. Nevertheless, having a dry mouth does not necessarily indicate that the salivary glands are not functionally normally. Many patients tend to have a dry mouth sensation even with normal salivary flow rates.
People with dry mouth may experience a burning sensation, altered taste, bad-smelling mouth, difficulty in speaking, chewing, swallowing, and wearing dentures. The patient often feels the need to drink liquids to help in swallowing food. In worse cases, dry mouth may result in oral mucosal soreness, angular cheilitis and oral candidiasis.
Causes of Dry Mouth
Many causes have been associated with dry mouth. The most common of them are medications, psychological conditions such as stress and anxiety, salivary gland disorders such as Sjogren's syndrome, systemic diseases particularly hypertension, diabetes, rheumatic diseases, asthma and radiotherapy of head and neck. Tobacco, smoking, coffee and soft drinks containing caffeine can also cause dryness in the mouth.
Dry mouth is more common among women and the prevalence seems to increase after 50 years of age. Age may be a risk factor because there is an increase in drug intake for chronic disorders among elderly people. More medications mean there is more probability that medication with dry mouth as a side effect is being consumed.
How is Medication Induced Dry Mouth Diagnosed?
You will be made to answer a series of questions and/or a visual analogue scale may be used where you will be asked to rate the severity of the dryness in your mouth.
Osailan et al. proposed several helpful signs of having a dry mouth some of which are
- frothy saliva
- no saliva pooling in the floor of the mouth
- fissured tongue
- cervical caries in more than two teeth
List of Medications that Cause Dry Mouth and How they Work
More than 400 drugs are associated with dry mouth as a side effect. Most of these drugs are used for common systemic diseases.
Although several mechanisms have been explained in the dry mouth due to drugs. It is important to understand that the mechanism of causing this condition depends entirely on the type of the drug and how it works.
Saliva consists of two components each secreted by an independent mechanism. The first component is fluid which includes ions and is produced by parasympathetic stimulation. The second is a protein component released mainly in response to sympathetic stimulation. The parasympathetic and sympathetic stimulation is under the control of the autonomic nervous system. Apart from this, hormones may also modulate the composition of the salivary gland.
1. Action on the Cholinergic System
Explaining simply, our body has an autonomic nervous system which acts unconsciously and regulates several of our bodily functions such as digestion, heart rate and salivary flow rate. These organs (namely heart, smooth muscles and exocrine glands) contain receptors which help mediate the action.
The receptors can be inhibited or stimulated by the action of the peripheral nervous system. Our salivary gland is also served with one of these receptors, namely the cholinergic receptor. A chemical released by nerve cells called neurotransmitter acetylcholine sends a signal to cells of salivary glands stimulating the flow of saliva.
Similarly, the same cholinergic receptor is present on the urinary bladder. In patients with urinary incontinence, an anticholinergic medication is given to inhibit the cholinergic receptor to reduce incontinence. This medication could target cholinergic receptors on the urinary bladder as well as salivary gland inhibiting the flow of saliva also.
The drugs that work by this mechanism are given in the below table
Duloxetine, Doxepin, Escitalopram
2. Medications used for Urinary Incontinence
Oxybutynin, tolterodine, fosterodine, trospium chloride, terazosin, propiverine hydrochloride, tamsulosin (acts by mechanism 2)
Fluphenazine enanthate or decanoate, Olanzapine, Quetiapine, Risperidone, Tiapride, Pipamperone, Donepezil
4. Diuretic agents and Psychotropics
Furosemide, Torsemide., Spironolactone, Triamterene, Bumetanide, Metalozone, Hydrochlorothiazide
2. Action on Sympathetic System
In addition to cholinergic innervation, the salivary glands also receive sympathetic innervation (alpha 1 and beta-receptors) Activation of either system will cause an increased secretion from salivary glands. For example, antihypertensive drugs such as clonidine and guanfacine inhibit alpha 2-adrenoceptor to cause a fall in blood pressure but also decreasing salivary flow.
The medicines that work by such mechanism are included in the table below.
5. Blood Pressure Lowering Medicines
Clonidine. Guanfacine, Alphamethyl DOPA
NIfedipine, Verapamil, Diltiazem ( work by another mechanism )
Fluoxetine, Venelafaxine, Nefazodone, Reboxetine, Bupropion hydrochloride
7. Appetite Suppressants
Sibutramine, Fenfluramine, Phentermine, Herbal supplement (Ma huang and kola nut)
8. Cold Suppressants
Pseudoephedrine, Cetrizine, Loratadine plus pseudoephedrine sulphate
9. Muscle Relaxer
10. Migraine Relief medicine
3. Other Drugs Inducing Dry Mouth
Inhaled medications produce the sensation of dryness but without any change in the saliva flow.
The mechanism by which antacids work to produce dry mouth is not clear. Some of the antacids may affect the salivary glands by binding to a hyrogen-potassium ATPase pump.
11. Inhaled Medications
Omeprazole, Cimetidine, Ranitidine
13. Pain relief drugs and Psychotropics
Atropine, Hyoscine, Morphine, Tramadol, Diazepam, Zopiclone
14. Anticancer Drugs
15. Anti-HIV Drugs
Didanosine and some others
Magnesium hydroxide, opthalmological, glucosamine
How to Cure Dry Mouth Problems?
1. Reach Out to Your Pharmacist or Doctor
If you are suspecting your medications, your first step should be to check your medications with your pharmacist or a doctor. Your healthcare provider may ask you a few questions to know if your medications are responsible for causing dry mouth. If found to be true, he/she may take one of the following steps (if required)
- Decrease the dose of your medication
- Replace the medications with other medications that may not cause dry mouth
- No changes in the medications should be made without first consulting with your doctor
2. Easy and Useful Remedies
- Proper hydration
- Increase in humidity at night-time
- Avoidance of irritating dentrifices, hard and crunchy foods
- Use highly purified lanolin-based moisturisers for lips.
- Use commercially available sugar-free chewing gums and candies: Especially chewing gums increase saliva flow and decrease friction in your mouth.
4. Saliva Stimulants and Substitutes:
- Choose a good gel, mouthwash, mouth spray and toothpaste suitable for your dry mouth problems.
- It is preferred that the product contains components such as olive oil, betaine, xylitol, and vitamin E.
- It is preferred if the product does not contain sodium lauryl sulfate, Cocamidopropyl betaine, and cinnamon.
- Avoid using alcohol-based mouthwashes. Although the high alcohol content may help in killing germs faster, it reduces the amount of saliva in your mouth.
- Lozenges containing mucin and anhydrous crystalline maltose are effective in treating dry mouth.
Biotene make products specifically for dry mouth patients including moisturising spray, oral rinse, gel, and lozenges form is very commonly used by people around the world.
Oasis moisturizing spray contains xylitol and glycerin components. The spray is alcohol-free and sugar-free.
I would also recommend saliva substitute gel, mouth spray and mouthwash by Xerostom.
Xylimelts are one of the best remedies I have known for dry mouth. They are like small discs like thing containing xylitol that you adhere to your teeth or gums. They come in mint-free and a mild mint flavour. They work well if you are looking for fast results. The only problem with these is that you will need to use them a lot more often than you think. Using twice in the night would help you sleep well.
FDA approved two medications, pilocarpine and cevimeline for treatment of dry mouth. There are also prescription saliva substitutes and stimulants such as Neutrasal mouth rinse or Caphosol saliva substitute. You would need the assistance of your healthcare provider to know when and how to use these.
1. Barbe, A.G. (2018). Medication-Induced Xerostomia and Hyposalivation in the Elderly: Culprits, Complications, and Management. Drugs Aging 35, 877–885 (2018). https://doi.org/10.1007/s40266-018-0588-5
2. Shetty, S. R., Bhowmick, S., Castelino, R., & Babu, S. (2012). Drug induced xerostomia in elderly individuals: An institutional study. Contemporary clinical dentistry, 3(2), 173–175. https://doi.org/10.4103/0976-237X.96821
3. Vinayak V, Annigeri RG, Patel HA, Mittal S. (2013). Adverse affects of drugs on saliva and salivary glands. J Orofac Sci; 5:15-20
4. Proctor G.B. (2015) Medication-Induced Dry Mouth. In: Carpenter G. (eds) Dry Mouth. Springer, Berlin, Heidelberg
This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.
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© 2020 Sherry Haynes