By Marcello Cherchi, MD PhD
For patients
Any medication has the potential to cause undesirable symptoms (“side effects”). In some cases these symptoms may appear to include disequilibrium. It is not always straightforward to figure out whether the symptom of disequilibrium arises because of a specific medication; see our discussion elsewhere about medication side effects. When this question comes up, your doctor may consider checking several basic tests of balance function, and if these do not reveal some other explanation, then it is reasonable to suspect the medication as the source of the symptom of disequilibrium, and the physician who prescribed that medication may consider reducing the dose, stopping it, or substituting it with another medication.
For clinicians
Medications can have unintended effects, both desirable and undesirable, and we direct the reader to our discussion elsewhere about medication side effects.
In otoneurology the question sometimes arises whether a given medication is responsible for vestibular symptoms (less commonly for auditory symptoms). In some cases, there may be clear grounds for suspecting such a relationship. A straightforward example of this would be when a patient is started on an antihypertensive medication, and within days develops lightheadedness upon standing, and is found on examination to have orthostatic hypotension; in such a case, the likely mechanism of the symptom is orthostatic hypotension, and the likely culprit is the antihypertensive medication.
But in many cases the relationship is not so obvious, such as when there is no clear temporal proximity between starting the drug and the onset of symptoms, or when the drug in question does not have disequilibrium listed as a common adverse effect. In such circumstances, if the history and physical examination are unrevealing, then it is medically reasonable to undertake a screening otovestibular workup; if those results do not discern a primary otovestibular disturbance, then it is also medically reasonable to suspect the medication as the cause of this symptom, and the prescriber may consider reducing the dose of the medication, discontinuing it, or substituting it.
