Is loss of smell or taste an adverse effect of strontium ranelate?
||Response from Gayle Nicholas Scott, PharmD
Assistant Professor, Eastern Virginia Medical School, Norfolk, Virginia
Disturbances of smell and taste are fairly common, with loss of smell (anosmia) the more frequent abnormality. Taste disturbances are usually related to olfactory (smell) dysfunction. The olfactory system affects quality of life by enhancing the palatability of food and warning of spoiled foods, smoke, and other environmental hazards.
Common causes of olfactory disturbance include anatomical problems (eg, nasal polyps and deviated septum) and insults to sensory perception (eg, viral infection, chronic sinusitis, allergic rhinitis, and cigarette smoke). Head injury and neurodegenerative diseases (eg, Alzheimer disease) can disturb the ability to smell and taste. Aging is also associated with olfactory dysfunction.
A variety of medications are associated with disturbances of smell and taste. For example, antivirals used in the treatment of HIV are associated with alterations of taste. Many chemotherapeutic agents interfere with the ability to smell and taste, an adverse effect that may be irreversible. Changes in taste have been reported in nearly all classes of cardiovascular drugs. Angiotensin-converting enzyme inhibitors, particularly when combined with calcium channel blockers or diuretics, are known for causing reversible loss or alteration of taste. Statins have also been associated with changes in smell and taste. Many drugs that affect the central nervous system (eg, antidepressants, antipsychotics, and antiepileptics) can adversely affect the ability to smell and taste.
Among dietary supplements, oral zinc is known to cause a metallic taste. Intranasal zinc (Zicam®) has been associated with irreversible loss of smell, prompting a US Food and Drug Administration public health advisory.
Strontium is a basic element located on the periodic table in the alkali earth metal column, which also includes lead and calcium. Strontium ranelate is available as a prescription drug for osteoporosis outside of North America. In the United States, strontium is sold as a dietary supplement as the carbonate, citrate, and other salts. Strontium ranelate is unique in that it appears to act by inhibiting bone resorption (like bisphosphates, estrogen, and other drugs) and stimulating bone formation (like fluoride and parathyroid hormone).
The most commonly reported adverse events in clinical studies of strontium ranelate are nausea and diarrhea, which were more common with higher doses. To date, strontium-induced smell or taste disturbances have not been reported in clinical trials. A search of Medline for case reports associating strontium with these adverse effects yielded no citations.
In summary, strontium has not been reported to cause changes in smell and taste. Other inducers of smell and taste disturbances such as medications or environmental agents such as cigarette smoke should be considered with appropriate referral to an ear, nose, and throat specialist.