Search PubMed⌕ Search

Biomedical subjects

H Halkin

Publications and source records attributed to H Halkin.

107 records · Page 6Linked to original sources
PubMed1973

Pharmacokinetics of digoxin: interpreting bioavailability.

Three subjects were first given a digoxin tablet in the fasting state and subsequently received the same formulation in the fed state, to simulate a spurious oral bioavailability difference. As expected, when measured by peak serum digoxin concentration as well as by area under the serum digoxin concentration-time curve the bioavailability of digoxin appeared to be higher in the fasting state than in the fed state. However, when measured by cumulative five-day urinary excretion of digoxin bioavailability was identical in both conditions.This simple experiment illustrates the fact that the estimation of bioavailability is subject to considerable methodological error, of which the clinician must be aware when evaluating reports on drug bioavailability in general and of digoxin in particular.

Administration, Oral↗
PubMedDate not supplied

Evaluation of the appropriateness of blood and blood product transfusion using preset criteria.

The use of 1930 units of blood or blood products during 765 transfusion episodes in 560 patients was reviewed. This represented one-half of all transfusions in a large medical center over a 2-month period. By clearly defined, present criteria, 42.3 percent of the episodes were found not to be appropriate. Whole blood and platelet transfusions were used more appropriately than those of red cells, cryoprecipitate, and fresh-frozen plasma. Blood transfusions were used more appropriately in the management of acute bleeding or anemia associated with cardiovascular problems. Three groups of patients were especially prone to inappropriate transfusions: those with end-stage renal disease or terminal cancer and cancer patients on chemotherapy. Age, sex, and specific hospital wards were not associated with inappropriate use. Most unjustified episodes occurred as a result of the overestimation of the immediate risk incurred by withholding transfusion.

Acute Disease↗
PubMedDate not supplied

Adverse effects of the fluoroquinolones.

Data on adverse reactions due to the quinolone antibacterial agents--ciprofloxacin, ofloxacin, pefloxacin, norfloxacin, and enoxacin--observed in a patient sample of approximately 30,000 are reviewed. Overall rates of adverse reactions were 4.0%-8.0%, and adverse reactions necessitated discontinuation of therapy in 1.0%-2.6% of patients. Patterns of organ-system involvement and of signs and symptoms were quite similar, with gastrointestinal effects predominating (nausea, vomiting, diarrhea, or abdominal pain in 1.0%-5.0% of the patients), followed by effects on the central nervous system (dizziness, headache, and/or insomnia in 0.1%-0.3% of the patients) and skin (0.5%-2.2% of the patients). Elevation in levels of hepatic enzymes occurred in 1.8%-2.5% of the patients, azotemia in 0.2%-1.3%, and eosinophilia in 0.2%-2.0%. These adverse effects were reversible after drug withdrawal and were generally not dose-dependent. Within the constraints of the relatively small number of well-documented patients and the unique mechanism of action of these antimicrobial agents, the safety profile of these drugs seems to make them acceptable for use when their administration is well directed and specific. In addition, close surveillance for new phenomena should be maintained.

Anti-Infective Agents↗
PubMedDate not supplied

Hyperinsulinemia is characterized by jointly disturbed plasma VLDL, LDL, and HDL levels. A population-based study.

Plasma very low density lipoprotein (VLDL) cholesterol and triglyceride, low density lipoprotein (LDL) cholesterol and triglyceridea, high density lipoprotein (HDL) cholesterol, glucose and insulin response (sums of 1- and 2-hour postload oral glucose levels), body mass index (BMI), and blood pressure were determined in a representative sample (n = 542) of the adult Israeli Jewish population. Persons with diabetes or on antihypertensive medications were excluded. Total VLDL and LDL fractions were estimated from their cholesterol and triglyceride subfraction levels that were standardized relative to the mean of the reference group (participants free of glucose intolerance, obesity, and hypertension--the GOH conditions). Hyperinsulinemia and disturbed levels of VLDL and LDL were defined as levels equal to or greater than the 75th percentile and those of HDL, equal to or less than the 25th percentile of their respective reference group distributions. When VLDL was disturbed jointly with LDL and HDL, the mean insulin response adjusted for age, gender, glucose response, BMI, blood pressure, and smoking was high compared to the reference group (166.0 vs. 122.5, p less than 0.001). With isolated disturbed VLDL, or disturbed LDL and HDL but normal VLDL, the mean insulin response resembled the reference group. The adjusted risk ratio for this jointly disturbed lipoprotein profile among hyperinsulinemic individuals was 3.4 (95% confidence limits 2.6 to 4.4, p less than 0.001) with no further association with the GOH conditions. We conclude that hyperinsulinemia is characterized by an atherogenic lipoprotein profile.

Diabetes Mellitus↗
PubMedDate not supplied

Senile cataract and glucose intolerance: the Israel Study of glucose Intolerance Obesity and Hypertension (The Israel GOH Study).

Association of "senile" cataract (SC) with glucose intolerance (impaired tolerance and diabetes) was assessed by sex and age in a random population sample comprising 930 individuals aged 40-70 yr, who underwent concurrent oral glucose tolerance test and ophthalmoscopy. The eye examination was performed without knowledge of the glucose tolerance status. SC was defined as lens opacification preventing visualization of the eyeground or as surgical aphakia due to SC. To assess the independent effect of hyperglycemia, glycosylated hemoglobin (HbA1) was determined in 769 participants. In men, no association was found between SC, glucose intolerance, and HbA1. In women of all ages, glucose intolerance was associated with an SC risk ratio of 6.1 (95% confidence limits 3.3-11.1; P less than 0.001). Furthermore, SC was associated in women with increased HbA1 independently of the effect of glucose intolerance (P less than 0.01). These findings confirm the reported association of SC with diabetes (although unlike the Framingham and HANES population studies, the association was confined in women), indicate its presence at all degrees of glucose intolerance, and suggest a possible independent role of nonenzymatic glycosylation in its pathogenesis.

Adult↗
PubMedDate not supplied

Factors associated with nonprescription of evolving modes of therapy--a model for drug use evaluation in hospitalized medical patients.

OBJECTIVE: To measure the rate of inappropriate underuse of drug therapy among hospitalized patients and to identify factors associated with nonprescription of two effective modes of therapy. DESIGN: A survey was conducted by retrospective chart extraction to measure the rates of nonprescription of two therapeutic modalities--aspirin and angiotensin converting enzyme inhibitors. Stepwise logistic regression was used to determine which factors were significantly associated with nonprescription of either drug. SETTING: Two internal medicine departments in a major community and referral hospital in Israel. PATIENTS: Those who were hospitalized through 1990 with a diagnosis on their discharge sheet of angina pectoris or congestive heart failure. A random sample selection was made to define the study population. RESULTS: The rates of nonprescription among patients in whom there are no drug contraindications were 54% (95% CI 47-62) for aspirin and 34% (95% CI 27-41) for angiotensin converting enzyme inhibitors. Three variables correlated independently with nonprescription of both drugs: hospitalization in ward B, nonuse of the drug prior to hospitalization, and secondary priority of the diagnosis angina pectoris or congestive heart failure on discharge sheet. CONCLUSIONS: Nonprescription of essential drugs is a common phenomenon that varies significantly among physicians. Inconsistency in application of knowledge to clinical practice, as well as a diversity of approaches toward interpretations of clinical study results, significantly influences the prescription rates of evolving modes of therapy.

Angina Pectoris↗