Introduction: Smell and Taste
The senses of taste and smell serve several functions and allow for a full appreciation of the flavors of foods. Smell and taste begin the initial response for saliva formation and digestion. Deficits in taste and smell can adversely affect food choices and intake, especially in the elderly, which can contribute to weight loss, malnutrition, impaired immunity, mood change, and functional decline.
Secondary consequences to older adults' changes in taste and smell may be evidenced by patients increasing intake of sugar and/or salt to compensate, which can have serious adverse effects in patients with diabetes, hypertension, and other cardiovascular diseases.
Good nutritional support with zinc supplementation may reduce the possibility of the onset of drug-induced smell and taste disorders. It's not uncommon for patients to experience a metallic taste with some medications. Good oral hygiene coupled with prevention of dry mouth may reduce the incidence of taste disturbances. If a patient shows signs of such a disturbance, an early discontinuation of the offending drug may prevent complete loss or irreversible distortion of smell or taste. Note that while a number of orally given (systemic medications) can affect smell and taste, medications administered nasally are especially troublesome for many persons.
Medications That Alter Smell & Taste
Common Medications Affecting Smell & Taste
Although this list is not comprehensive, common medications associated with taste or smell disturbances include the following:
angiotensin-converting enzyme inhibitors (notably captopril), which are among the medications most commonly associated with taste disturbances, including decreased sense of taste (hypogeusia) and a strongly metallic, bitter, or sweet taste;
medications known to dry the oral cavity (eg, anticholinergics, antihistamines, and antidepressants);
antibiotics (eg, penicillin, tetracycline, macrolides, and fluoroquinolones, among others);
antiparkinsonian agents (levodopa/carbidopa);
anticonvulsants (eg, carbamazepine, phenytoin); and
antithyroid agents, cholesterol-lowering agents, blood pressure medications, and muscle relaxers.