Taste disturbances related to medication use

The patient is an 88-year-old male who presented to a weekly pharmacy-run blood pressure (BP) screening at the retirement community where he resides. His past medical history consists of hypertension, hyperlipidemia, and altitude sickness. The patient's BP was 122/48 mmHg, which was lower than his average (148/64 mmHg). The patient was asked a series of questions to determine the cause of the BP decline. He commented that he does not drink much water, stating, "It tastes bad." The patient started acetazolamide six years ago for treatment of altitude sickness and it was suspected that this was contributing to the patient's taste disturbance. The pharmacist apprised the physician that the patient was experiencing a probable adverse effect from a medication and then developed a program to taper the medication based on the pharmacokinetics of the drug. After the drug was completely tapered off, the patient reported that not only had his sense of taste returned to normal, but his cognition had improved as well. He previously could not perform some of his instrumental activities of daily living without help, but now believes he can continue to live independently. He reported no dizzy spells since discontinuing the medication and his BP has remained stable.