years. Further work indicates that cautious, slow lowering of blood pressure to normal levels in the chronic hypertensive together with continued control results in a resetting of the cerebral pressure-flow auto regulation curve to the left—the more normal configuration.10,63 A few studies in middle-aged hypertensives suggest that acute initiation of antihypertensive drugs can lower cerebral perfusion modestly,12 but chronic administration of appropriate doses of antihypertensive medications does not adversely affect cerebral blood flow.12,66,67
It is surprising that there are few data from large-scale clinical trials regarding the toxicity of antihypertensive medication in the elderly. A group of investigators from the Hypertension Detection and Follow-up Program reported that the total rate of adverse effects from the treatment of mild to moderate systolic/diastolic high blood pressure was less for the subgroup aged 60 to 69 at entry than for those under the age of 50.22 These data are helpful but should be viewed with caution: persons in the 60-69 age range are classified as the "young old" and may not be as susceptible to side effects as the "old old" (aged 75 and older). In addition, such trials tend to select "well" subjects and are not necessarily representative of elderly patients who have one or more serious comorbid diseases.
The largest available data set on the toxicity of antihypertensive therapy in the elderly comes from the European Working Party on Hypertension in the Elderly and its randomized study of the efficacy of the treatment of systolic/diastolic high blood pressure in a cohort of patients with a mean age at entry of 72 years.4 Early reports from this trial indicate that treatment with a thiazide-triamterene combination (followed by alphamethyldopa as a second-step agent when needed) resulted in mild increases in glucose intolerance, serum creatinine, and uric acid and a mild decrease in serum potassium in the treatment group.2 Treatment does not appear to have had a significant long-term effect on serum cholesterol levels.5 To date, only limited data on side effects have been reported, but there was no significant difference between the treatment and control groups in the rate at which patients were dropped from the study because of presumed drug-related side effects. The biochemical side effects listed above were not thought to outweigh the benefits of treatment.
Questions still remain about possible negative impacts of antihypertensive therapy on the quality of life for elderly patients. Only a few trials of antihypertensive drug therapy (in any population, young or old) have adequately quantified the impact of reported adverse effects on subjects' quality of life.19,70 Most trials have simply counted the total number of reported adverse effects without attempting to describe either qualitatively or quantitatively their