Fundamentals of Treatment Planning. Lino Calvani
and which of these could possibly cause dry mouth.61-63 This is one of the reasons why it is crucial to collect comprehensive medical and dental drug data during the first diagnostic phase.
To date, there are 25 categories of medications representing some 133 generic drug names that have xerostomia as a side effect, as follows:
1. Anorexiant.
2. Antiacne.
3. Antianxiety.
4. Antiarthritic.
5. Anticholinergic/antispasmodic.
6. Anticonvulsant.
7. Antidepressant.
8. Antidiarrheal.
9. Antihistamine.
10. Antihypertensive.
11. Anti-inflammatory/analgesic.
12. Antinauseant.
13. Antiparkinsonian.
14. Antipsychotic.
15. Antisecretory.
16. Antispasmodic.
17. Antiviral.
18. Bronchodilator.
19. CNS stimulant.
20. Decongestant.
21. Diuretic.
22. Migraine.
23. Muscle relaxant.
24. Narcolepsy, narcotic, analgesic.
25. Ophthalmic sedative.
Composite drug therapies can cause xerostomia. It is common for patients to take several drugs simultaneously for various problems, and their interaction may exacerbate dry mouth. Therefore, during the initial diagnostic phase, it is important that we scrutinize the patient’s answers to the questionnaires and investigate a bit deeper in our interview with the patient to ensure that we are aware of all the drugs the patient is taking. We also need to have a sound knowledge of their effects, side effects, and interaction with each other to properly diagnose and treat our patients and avoid future unexpected surprises or possible misunderstandings.63
Dysgeusia and taste impairment
This important symptom is often underestimated and especially affects elderly patients. Taste, or gustatory perception, is a natural warning system that developed through evolution so that, apart from tasting when food or drink is good, humans are able to detect when it is spoiled and may endanger their health and life. This includes the ability to detect substances to which we may be allergic. Taste receptors are located on the tongue as well as on the roof, sides, and back of the mouth, on the epiglottis, and in the throat.32,64,65
Dysgeusia is a condition in which a foul, salty, rancid or metallic taste sensation appears and remains in the mouth. Sometimes, patients report that this symptom started with the delivery of a prosthetic device or some other metal object in their mouths. Patients may attempt to place the responsibility for the symptom on the prosthodontist/s who planned and delivered the restoration. We need to investigate the cause of the dysgeusia carefully because sometimes it is caused by something other than the restoration, in which case we need to explain this in a gentle and kind way to the patient. The U.S. Department of Health and Human Services – National Institutes of Health reports that in the USA some 200,000 people visit a doctor each year for problems with their chemical senses, which includes taste and smell. This significant number of patients, which in fact may be just the tip of the iceberg, means that many people experience problems with these two senses. It is therefore usually too simplistic to relate the symptom of dysgeusia to a purely prosthodontic cause. Furthermore, taste and smell are closely related, and it is sometimes confusing in certain conditions to tell whether a patient has a taste or a smell disorder.66-69
Taste as a risk factor
Taste disorders may create serious health problems as they can be a risk factor for stroke, diabetes, heart disease, and other conditions where a careful diet must be followed. Impaired taste may cause patients to dramatically limit their food intake so that they experience massive weight loss, with the teeth having nothing to do with it.70,71 This situation may also cause depression. This is important to know and remember in the initial diagnostic phase.
Possible causes of dysgeusia and altered taste disorders are:
1. Drug use or abuse.
2. Poor oral hygiene.
3. Third molar extraction surgeries.
4. Upper respiratory tract and middle ear infections and surgeries.
5. Head injuries.
6. Radiation therapy for head and neck cancer.
7. Exposure to chemicals such as insecticides.
8. Central nerve system pathologies.
When loss of taste is a chief complaint that cannot be related to a disease in the oral cavity, we should advise the patient to consult a physician, as this symptom may be a precursor sign (together with an impairment of the sense of smell) of a severe nervous system pathology such as Parkinson’s disease or Alzheimer’s disease.72,73
Drugs that may affect taste
When a patient reports an altered, reduced or absent ability to taste as a chief complaint, we need to ensure that we see and understand the full clinical picture. As described in the previous section regarding dry mouth, an affected sense of taste may be due to drugs the patient is taking. It is therefore important to know exactly what these are, so that if patients claim to have an affected sense of taste due to a prosthesis or other dental work in their mouths, we can explain to them that it may be due to the drugs they are taking.74
There are 46 categories of medications representing some 151 generic drug names that can cause an altered or lost sense of taste as a side effect, these being:
1. Alcohol detoxification medications.
2. Alzheimer’s disease medications.
3. Analgesics (NSAIDs).
4. Anesthetics (general and local).
5. Anorexiants.
6. Antacids.
7. Antiarthritics.
8. Anticholinergics.
9. Anticonvulsants.
10. Antidepressants.
11. Antidiabetics.
12. Antidiarrheals.
13. Antiemetics.
14. Antifungals.
15. Antigouts.
16. Antihistamines (H1) antagonists.
17. Antihistamines (H2) antagonists.
18. Antihyperlipidemics.
19. Anti-infectives.
20. Anti-inflammatories/anti-arthritics.