Biomedical subjects
K M Potempa
Publications and source records attributed to K M Potempa.
Drug use and effects in older adults in the United States.
Aging markedly influences drug use and drug effects. The purpose of this review is two-fold: (i) to examine how social, economic, and psychological factors, compliance, and prescribing patterns affect drug use in institutionalized and non-institutionalized older adults in the United States, and (ii) to illustrate how physiological aging, actions of drugs, and adverse drug reactions influence drug effects. Recommendations for further study include identification of adverse reactions, and examination of drug taking behavior in older adults who are alone or debilitated. Research is especially needed for those in nursing homes and for those who are old-old (over 85 years).
Reduced cardiac output and exercise capacity in patients after MI.
This article summarizes the literature and suggests directions for future research concerning rehabilitation potential, impairment, and reduced cardiac output after myocardial infarction (MI). Current evidence suggests that cardiac output and maximal exercise capacity are reduced in some post-MI patients. The conceptual model of rehabilitation potential presented emphasizes the need for careful assessment of the state of underlying pathology present after MI when evaluating the response to exercise or exercise training.
The relationship of resting and exercise blood pressure in subjects with essential hypertension before and after drug treatment with propranolol.
OBJECTIVE: To investigate the relationship between clinic resting blood pressure (BP) and exercise BP in subjects with established essential hypertension during placebo and propranolol-treated phases. DESIGN: Prospective, placebo-controlled, cross-over trial. SETTING: University-affiliated medical center. PATIENTS: A convenience sample of 38 patients with essential hypertension, 34 men and four women, who ranged in age from 22 to 62 years (mean = 44 years, SD = 10.7). Subjects were diagnosed with mild to moderate diastolic or mixed systolic/diastolic essential hypertension at least 1 year before study entry. They had no clinical evidence of secondary hypertension, diabetes, heart, liver, pulmonary, or renal disease. OUTCOME MEASURES: Resting and exercise BP. INTERVENTION: Antihypertensive medication was tapered off and subjects were free of all prescription drug treatment for 2 weeks. They received placebo for an additional 2 weeks. Subjects then received treatment with propranolol at a dose necessary to control resting blood pressure for 4 to 6 weeks. At the end of both the untreated and treated phases, subjects were given a graded maximal exercise test on a bicycle ergometer. RESULTS: Propranolol effectively reduced mean resting and maximal exercise BP. The nonsignificant correlation between clinic resting and maximal exercise systolic BP was low in both phases. The correlation between clinic resting and maximal exercise diastolic BP was only moderate, but statistically significant (untreated, r = 0.43; p < 0.01; treated, r = 0.53; p < 0.001). For systolic BP or diastolic BP, there were no significant relationships between percent drop in BP because of propranolol at rest or maximal exercise. Clinic resting BP was not a valid predictor of maximal exercise BP. Degree of control of clinic resting BP was not a valid predictor of control observed at maximal exercise. CONCLUSIONS: Resting BP should not be used as a predictor of BP during maximal exercise in the untreated condition or with treatment with propranolol.
Blood pressure reactivity in the evaluation of resting blood pressure and mood responses to pindolol and propranolol in hypertensive patients.
OBJECTIVE: The purpose of this exploratory study was to evaluate the relationship of blood pressure reactivity during exercise to treatment responsiveness to two commonly used beta-adrenergic blocking agents, propranolol and pindolol. DESIGN: Prospective, placebo-controlled, balanced, cross-over clinical trial. SETTING: University-affiliated medical center. PATIENTS: A convenience sample of 19 white male subjects with mild to moderate essential hypertension were studied. The mean age was 63.4 years (SD = 5.2). The mean resting systolic blood pressure (SBP) was 158.6 mm Hg (SD = 12.3) and mean resting diastolic blood pressure (DBP) was 96.4 mm Hg (SD = 8.6). They had no clinical evidence of secondary hypertension, diabetes, heart, liver, pulmonary, or renal disease. OUTCOME MEASURES: Resting blood pressure; blood pressure reactivity to exercise; self-report measures of depressive symptoms, and mood disturbances. INTERVENTION: Antihypertensive medication was tapered off and subjects were free of all prescription drugs for 2 weeks. Subjects were randomly assigned to propranolol-pindolol or pindolol-propranolol group. Each 4- to 6-week treatment phase was preceded by a 2-week placebo phase. At the end of the initial placebo phase and each active drug treatment phase, subjects were assessed for depression and mood disturbances by use of standardized measures and were given a graded exercise test on a cycle ergometer. Resting blood pressure was assessed weekly and before each exercise test. RESULTS: Significant relationships between DBP reactivity to exercise during the placebo phase and the degree of blood pressure and mood responsiveness to pindolol and propranolol treatment were observed. Subjects demonstrating high DBP reactivity required high doses of beta-blocker for resting DBP reduction, and these subjects showed the least change in mood at high doses. Similar patterns were found for the relationship of SBP reactivity and blood pressure and mood responsiveness to drug treatment, but these relationships were not statistically significant. CONCLUSIONS: DBP reactivity to exercise during the placebo phase provides unique information about the essential hypertensive patient. DBP reactivity and drug dose were important determinants of resting blood pressure and mood responsiveness to both pindolol and propranolol. DBP reactivity and perhaps SBP reactivity may be useful measures in the study of central adrenergic and peripheral cardiovascular pathophysiology.