With the growing importance of disorders like Alzheimer's disease, and the natural apprehension that stalks patients each time they forget something, it is common to look for a correctable cause of memory slippage and a natural target is medication. This raises the question: Do antihypertensive drugs impair memory?
Some antihypertensive medication package inserts mention memory loss in the adverse event sections. For example, several of the β blocker inserts include “short-term memory loss” under central nervous system effects. However, the effects of drugs are probably overshadowed by the substantial role that blood pressure itself plays in ultimate cognitive decline. There appear to be at least two lessons in this story.
The first is that the cognitive decline evident in the 70-year-old patient is associated with blood pressures when the patient was 40 or 50 years old,1 underscoring hypertension as a risk factor for later cognitive decline and memory loss. The second lesson is that antihypertensive therapy generally helps, rather than attenuates, cognitive function preservation. This latter finding was evident in the Systolic Hypertension in Europe (Syst-Eur)2 study in which older subjects with systolic hypertension treated with a calcium channel blocker-based regimen compared with a placebo-based regimen were found to have half the incidence of dementia over the next 4 years. At the recent 24th Congress of the European Society of Cardiology meetings two interesting additional studies have “raised the bar” with respect to this issue.
The Perindopril Protection Against Recurrent Stroke Study (PROGRESS) used an angiotensin-converting enzyme inhibitor-diuretic regimen to treat patients who already had a stroke.3 In addition to reducing subsequent stroke occurrence, this study showed a protection of cognitive function in the treatment group. Interestingly, this protection extended even to the nonhypertensive patients treated with drug therapy. The Study on Cognition and Prognosis in the Elderly (SCOPE) trial tested the effectiveness of an angiotensin receptor blocker against a diuretic in 70–89-year-old hypertensives. The findings from the SCOPE trial are thought-provoking because it purports that angiotensin receptor blocker treatment has a strong favorable effect to preserve memory and cognitive function even at the extreme of age and in patients with some prior cognitive impairment.3
The last comment is that it isn't clear that drug therapy for hypertension induces memory loss. In a most recent investigation specifically addressing this, data suggests that the jury is still out.4 If anything, when objectively tested, drug therapy appeared to maintain or improve cognitive function in hypertensives, and in this study two different β blockers were employed.4 However, we are learning that not all antihypertensive medications confer equal amounts of benefit despite similar degrees of blood pressure reduction, and it is probable that differences in outcomes like dementia will become increasingly evident as more is learned about the connections between elevated blood pressure and cognitive ability.