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Biomedical subjects

M Weintraub

Publications and source records attributed to M Weintraub.

At least 127 records · Page 7Linked to original sources
PubMed1980

Age-associated changes in tissue distribution and uptake of 3H-digoxin in mice and guinea pigs.

The influence of age on tissue distribution of digoxin in mice and guinea pigs and uptake by mouse heart slices was investigated. 4 h after a single dose of 3 H-digoxin, tissue:plasma ratios were significantly greater in very young animals and declined with increasing age. A similar relationship was apparent for packed red blood cell:plasma concentration ratios in mice. Uptake of 3H-digoxin by heart tissue slices was also higher for 21-day-old mice than 200-day-old mice. These data seem to correlate with the larger volume of distribution of digoxin observed in the young. Tissue digoxin relative to plasma concentration seems higher in the young, although they appear less sensitive to the effects of cardiac glycosides.

Aging↗
PubMed1980

Age-associated differences in guinea pig myocardial Na+, K+-ATPase activity and ouabain inhibition and in Mg2+-ATPase activity.

The influence of age on activity of cardiac Mg2+-ATPase and Na+, K+-ATPase from guinea pigs was studied. Tissue homogenates and NaI-washed membranes were prepared from the heart tissue of 10- to 12-day-old or greater than 12-month-old male guinea pigs. Tissue homogenates from the young animals had significantly greater enzyme activities than those from the older. Na+, K+-ATPase activity in young tissue preparations was less inhibited by ouabain than in older tissue preparations. These differences may be related to the observations that young animals and humans are less sensitive to cardiac glycosides than adults.

Adenosine Triphosphatases↗
PubMed1980

Prescription prices under the New York generic substitution law.

We evaluated the New York State generic substitution law. This law mandates substitution of a less expensive product if the physician signs the prescription for an eligible brand name drug on the line marked "subsitution permissible." We purchased drugs by brand name and generically before the law went into effect. Later, we purchased the same drugs in the same stores using the formats "brand-dispense-as-written," "brand-substitution-permissible," and "generic." Mean savings from generic prescribing or substitution increased from 12.1% +/- 20.4% before the law to 26.2% +/- 10.5% (brand-substitution-permissible) and 27.2% +/- 14.2% (generic). Prices for the same drug written the same way varied enormously among pharmacies. Brand-dispense-as-written, brand-subsitution-permissible, and generic prices in the same store varied substantially and unpredictably. Savings were not passed on to consumers in 29% of postlaw comparisons. Assuring maximal savings requires extensive comparison shopping.

Drug Labeling↗
PubMed1979

Digoxin-prescribing. Mostly good news.

We examined digoxin-prescribing in 47,000 prescriptions written predominantly by physicians in a large family medicine practice. Two hundred fifty-four patients received 511 digoxin prescriptions. Dose adjustments for age (16% decrease in patients older than 64 years), for renal disease (33% decrease), and for atrial fibrillation (39% increase) followed good prescribing practices. Appropriately lower loading doses were used for digitalization. However, despite continuing concern over the bioavailability of generic digoxin tablets, less than 40% of digoxin prescriptions in this study were written for the innovator's brand-name product (Lanoxin).

Adult↗
PubMed1979

Methodology for demonstrating sustained efficacy of hypnotics: a comparative study of triazolam and flurazepam.

To test for sustained hypnotic efficacy, triazolam (0.6 mg) or flurazepam (30 mg) was given to chronic insomniac patients for 7 consecutive nights in parallel, double-blind design. Triazolam at this dose was an effective hypnotic by all usual subjective measures and did not produce appreciable hangover. Flurazepam performed similarly. For either drug, comparison of the mean scores for the first 2 nights with that for the last 2 nights for any of the parameters did not reveal any significant difference. Thus, both triazolam and flurazepam showed sustained efficacy for 1 week at these doses. Some interesting theoretical and practical questions about the measurement of sustained efficacy of hypnotics in situations of repetitive dosing were addressed by the study. While a placebo control is desirable, the results obtained may be uninterpretable. An acute-care hospital setting may not be the ideal setting for doing such studies. There were indications from the study that the first-night results in a hypnotic clinical trial may be atypical.

Adult↗
PubMed1978

Relationship of serum and myocardial digoxin concentration to electrocardiographic estimation of digoxin intoxication.

Serum and myocardial digoxin levels were studied in 18 patients who came to autopsy. An independent analysis of electrocardiograms prior to death was made to ascertain the relationship between serum and tissue levels of digoxin and clinical estimation of drug toxicity. Patients with arrhythmias of digoxin toxicity had higher mean serum and tissue digoxin levels than patients without arrhythmia. There was overlap in the patient groups, however, and the differences were not statistically significant. The tissue to serum ratio was lower in the toxic patients. The latter phenomenon is unexplained but may be related to decreased tissue binding.

Aged↗
PubMed1977

Acetazolamide-induced interference with primidone absorption. Case reports and metabolic studies.

Effects of acetazolamide on primidone plasma levels were studied in three patients. Apparent interaction occurred in two patients. Primidone was not detected in the plasma when given orally with acetazolamide in one patient. In another, peak serum concentration was delayed, with corresponding delays in urinary excretion of primidone and metabolites. Plasma and urine concentrations of the two metabolites, phenylethylmalonamide and phenobarbital, were also studied.

Acetazolamide↗
PubMed1977

Free-living volunteer's motivations and attitudes toward pharmacologic studies in man.

Two groups of volunteers who had participated in pharmacologic studies were interviewed about their impressions of such studies. One group was from a university community, the other from the pharmaceutical industry. The differences between the two groups were correlated with their respective backgrounds. Both groups had favorable impressions about drug studies and investigators. Most were satisfied with the information given them about the nature and risks of the studies, but some believed that a written description of the study that they could consult at home would improve their understanding of the information. Financial reward was the primary reason given by both groups for volunteering, but the perceived risk of the study was the ultimate deciding factor. The volunteers disliked having their mobility restricted and for this reason might not be willing to participate in long-term studies, such as those formerly carried out in prisons. Alternative sources of volunteers for long-term studies will have to be found.

Adult↗