A healthy patient produces saliva at the rate of 1 ounce per hour. In a person with xerostomia or dry mouth, the rate is reduced to approximately 1 teaspoonful per hour. Besides adding in chewing and digestion, saliva maintains the pH balance in the mouth by secreting bicarbonate ions, produced in the salivary ducts, which combine with and neutralize the acid ions produced in the fermentation process. Inadequate production of saliva is a risk factor for dental cavities.
The most common causes of xerostomia:
- Lesions in the salivary glands or duct obstruction
- Radiation injury to the salivary glands
- Sjogrens syndrome: is nine times more common in females than males. Most common disease affecting salivary gland. These patients also experience dry eyes, dry skin, difficulty in swallowing and swollen inflamed joints
- High blood pressure, alcohol, tobacco, caffeine use
- Cystic fibrosis
- Lupus, Crohn’s disease, Biliary cirrhosis, HIV
Many drugs are commonly implicated in causing xerostomia
- Numerous drugs used for mental health: tranquilizers like Valium, Antidepressants like Elavil, Prozac, Zoloft, Effexor, and Wellbutrin. Lithium, Valproic acid, numerous antipsychotics.
- Some blood pressure drugs: clonidine, enalapril, methyldopa, prazosin
- Diuretics “fluid pills” : HCTZ, Furosemide, Spironolactone
- Anticholinergics: Benztropine, Trihexyphenidyl, Atropine, Dicyclomine, Hyoscyamine.
- First generation antihistamines for allergy: Diphenhydramine, promethazine, hydroxyzine. This is primarily to their anticholinergic side effects.
OTC treatment of Xerostomia: topical treatment of xerostomia is available as “Saliva substitutes”. Saliva substitutes may be most useful before sleep, because viscosity of saliva changes at night; after waking at night with dry mouth symptoms, during telephone conversations, during social and workplace interactions, and in patients with dentures.
- Contain carboxymethylcellulose and or mucins for lubrication and viscosity.
- Contain xylitol or sorbitol as sweeteners. Remember sugar alcohols can cause diarrhea.
- Trade names: MouthKote, Biotene Oralbalance gel, Biotene mouth spray, Salivart, Xero-lube
- Sip water and sugar free drinks. Avoid sugary drinks and caffeine
- Chew Sugarless gum or suck on sugarless hard candies
- Use a humidifier
- Breathe through the nose, not the mouth
- Practice good oral hygiene: brush, floss, see dentist regularly.
- Treat cracked lips with petroleum jelly or lip balm
- Eat high moisture foods (Mashed potatoes instead of French fries). Avoid spicy foods
- Avoid highly acidic foods/drinks as well due to their erosive effect on teeth. With limited saliva production, these drinks can quickly damage the protective enamel layer.
RX Treatment: pilocarpine (Salagen) and cevimeline (Evoxac) will stimulate the flow of saliva. Patients may complain of excess sweating and gastrointestinal upset.
Patients should be monitored for development of oral candidiasis (thrush).
Your Thompson Pharmacist can scan your med list and see if any drugs can cause dry mouth, as well as recommend over the counter products to make your mouth more comfortable. Go ahead and ask… at Thompson Pharmacy it’s all for you!!