Masuo K, Mikami H, Ogihara T, Tuck MD
Changes in frequency of orthostatic hypotension in
elderly hypertensive patients under medications
Am J Hypert
(Mar) 9:263-268 1996

Choice of antihypertensive medication in the elderly is often
complicated by the development of orhthostatic hypotension. The
authors treated 50 normotensive and 50 hypertensive subjects with one
of 5 different medications in a double blinded fashion.
Blood pressure measurements were taken after an equilibration
time of 2 minutes standing and 10 minutes supine over intervals
spanning 2 years. Interestingly, over 25 percent of patients exhibited
at least a 10% fall in mean BP regardless of the category of
medication used (nifedipine, metoprolol, enalapril, prazosin, or
thiazide) and, not surprisingly, this effect worsened with increasing
age and dosage of medication. Orthostatic changes did, however,
decrease with time and normalization of blood pressure in hypertensive
patients. Elderly subjects with orthostatic hypotension were more
likely to have a diminished ratio of standing to supine plasma
norepinephrine hinting once again at the clinical suspicion that this
population has an attenuated sympathetic nerve activity response to
change in posture.
Comment: For clinicians, the take home point of this
study is that all classes of antihypertensive medications in the
elderly carry a real and perceptible risk of orthostatic hypotension
at initiation. These changes often improves with time and
normalization of blood pressure. (Sri Narsipur, MD, SUNY-HSC at
Syracuse, NY)