Faculty Bibliography

BACKGROUND:Pharmacologic treatment of hypertension reduces risks of stroke, congestive heart failure, renal failure, and mortality, but whether medications, once begun, need to be continued for life is uncertain. METHODS:Several search strategies on MEDLINE using key words "medication," "withdrawal," "discontinuance," and "therapy" in several combinations, nested within "hypertension," were not productive. Accordingly, articles known to the authors and citations within them were reviewed. A survey of a random sample of members of the New York Academy of Family Practice was conducted to ascertain current practice of practicing physicians. RESULTS:Eighteen studies of antihypertensive medication withdrawal were located and all were reviewed. In 12 trials average success rates of 40.3 percent after 1 year of follow-up and 27.7 percent after 2 years were achieved. In six studies limited to elderly patients, an average success rate of 26.2 percent was obtained for periods of 2 or more years. The trials, however, were heterogeneous in design, patient selection criteria, and follow-up. The survey of family physicians indicated that 79.1 percent attempt withdrawal of antihypertensive medications in hypertensive patients whose blood pressure is controlled and who are without symptoms from medication. CONCLUSIONS:We conclude that successful withdrawal of antihypertensive medications can have substantial benefits with few or no adverse consequences and might be successful in about one third of patients. Additional research is required to substantiate rates of successful medication withdrawal, to define the best method of withdrawing medications, and to delineate characteristics of patients in whom withdrawal is most likely to succeed.

A well coordinated plan that includes a mechanism for surveillance, rapid antigen detection testing and viral culture, infection control techniques and chemoprophylaxis is effective for aborting outbreaks of influenza A in the nursing home. Amantadine has been better studied in this situation, and experience with rimantadine is limited. The safety and efficacy of our dose guidelines for nursing home residents need to be studied and directly compared with rimantadine dose guidelines. Except for chemoprophylaxis, these guidelines can be applied to outbreaks of influenza B as well.

The effect of plasma protein binding changes on drug clearance is an important concept in clinical pharmacology. In a hypoalbuminemic patient receiving acetazolamide, albumin infusion (50 g) increased acetazolamide plasma protein binding towards normal as the serum albumin concentration rose (r = 0.91, P < .001). The ratio of acetazolamide renal plasma clearance to creatinine clearance decreased as serum albumin levels increased (r = 0.78, P < .05) and the unbound drug fraction fell (r = 0.88, P < .01), but clearance ratios based on unbound plasma acetazolamide levels did not change. Albumin infusion resulted in a nonparallel decline over time between plasma and unbound plasma acetazolamide concentrations. These data demonstrate that, over the range of observed serum albumin concentrations, acetazolamide renal plasma clearance is sensitive to changes in plasma protein binding. Furthermore, our findings emphasize the importance of measuring unbound drug levels when protein binding changes occur during the course of drug disposition studies. Finally, this methodology allows for the fascile assessment of the effects of plasma protein binding changes on renal drug clearance.

Presence of cytomegalovirus (CMV) specific immunoglobulin M (IgM) is generally considered strong evidence of current or recent CMV infection. Sera from 110 elderly individuals (age range 61-100 years) were compared with sera from 87 younger individuals (age range 16-47 years). Prevalence of CMV IgM was found to be 30% in the older group (mean age 83 years) and only 6% in the younger group (mean age 29 years). In spite of increased CMV antibody levels, none of the elderly individuals were symptomatic. Viral cultures of urine from 72 elderly individuals were negative for CMV. These results suggest that the presence of CMV-specific IgM must be interpreted with caution in an elderly population.