PubMed Health⌕ Search

Biomedical subjects

F E Karch

Publications and source records attributed to F E Karch.

13 recordsLinked to original sources
PubMed1979

An algorithm for the operational assessment of adverse drug reactions. II. Demonstration of reproducibility and validity.

The reproducibility and validity of an algorithm for diagnosis of adverse drug reactions (ADRs) were tested in a clinical spectrum of 30 suspect cases. Using a questionnaire derived from the algorithm the three algorithm developers (nonexperts) agreed on the probability of ADR in 67% of cases, with pair-wise agreement varying from 73% to 87%. The pair-wise agreement of two clinical pharmacologic experts rose from 47% without the algorithm to 63% with the algorithm, with Kw, a chance-corrected index of weighted agreement, increasing from 0.26 to 0.57. The algorithmic assessments of the three nonexperts agreed with expert consensus in 80% to 83% of cases. The ADR algorithm appears to provide a reproducible and valid method of evaluating the likelihood of ADRs in individual patients. Its use can help improve the diagnostic and epidemiologic approach to these important, complex clinical phenomena.

Adult↗
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

Low back pain in family practice: a case control study.

Eighty-three women between the ages of 25 and 44 years who presented with low back pain during a one-year period were compared with a control group of women matched by age and socioeconomic status. The patients with low back pain presented a larger number of problems to their family physicians during the course of the year, but there were no significant differences noted in the prevalence of symptoms of anxiety and depression during their visits, or in the number of psychological problems presented by the two groups, or in the number of psychoactive medications received for problems other than low back pain. The results suggest that low back pain patients may represent a group who more readily present their symptoms to physicians but that they are no more likely to have psychological problems than similar patients who do not have low back pain.

Adult↗
PubMed1978

Effect of lithium on plasma chlorpromazine levels.

The interaction of lithium and chlorpromazine (CPZ) was studied in healthy volunteers in a randomized crossover study. Each subject ingested two doses of CPZ (100 mg) as the liquid concentrate: (1) without concurrent lithium therapy and (2) after a 7-day treatment with lithium carbonate (900 mg/day). When CPZ was administered with lithium, peak plasma CPZ levels were 40.3% (mean) lower than those without lithium (p = 0.006), and the area under the CPZ plasma concentration time curve was 26.6% smaller (p = 0.08). The time to reach peak plasma CPZ levels was similar in both groups. All subjects slept for 4 to 6 hr after oral CPZ and had a maximum fall in both systolic (8 to 32 mg Hg) and diastolic (5 to 23 mg Hg) blood pressure at the time of peak plasma CPZ concentration. This lithium-CPZ interaction may explain the low plasma CPZ levels reported previously in psychiatric patients taking both lithium and CPZ.

Adult↗
PubMed1978

Diatrizoate enemas: facts and fallacies of colonic toxicity.

Rats were given enemas of Gastrografin in two strengths, Renografin--76, and Tween--80 in a 10% dilution. There were no deleterious effects on the colons with these media used in volumes to fill the colon. Severe changes resulted from volumes which produced overdistention.

Animals↗
PubMed1978

Biochemical, morphologic and physiologic changes in the adrenal glands of rats chronically treated with phenobarbital.

Biochemical and ultrastructural changes in the adrenal glands of rats were observed after long-term phenobarbital treatment. At the fine structural level, the parenchymal cells of the phenobarbital-treated rats resembled cortical cells that had been stimulated by adrenocorticotropin. A significant finding was the presence of very large hollow mitochondria characterized by loss of vesicles and cristae with retention of the double outer membrane. Arylesterase (EC 3.1.1.2) activity, the marker used for rough endoplasmic reticulum, was significantly diminished. Since rough endoplasmic reticulum is present primarily in the adrenal medulla and not the cortex, the relative decrease in arylesterase activity is consistent with the morphologic adrenal cortical hyperplasia. Trypsin-like (EC 3.4.4.4) enzyme activity was increased. The plasma corticosterone response to adrenocorticotropin injection was not significantly different in treated and control rats. The similarity of the observed mitochondrial changes to the reported mitochondrial cavitation in the adrenal glands of rats treated with aminoglutethimide is discussed.

Adrenal Glands↗
PubMed1977

Toward the operational identification of adverse drug reactions.

The evaluation of adverse drug reactions in clinical practice is somewhat arbitrary and is characterized by considerable differences of opinion. This report presents a decision table algorithm approach toward the development of an operational system for the identification of adverse drug reactions. The algorithm incorporates an estimate of the certainty of the link between the untoward clinical event and the suspect drug, and examines the underlying causes of the identified drug reactions. Use of such a system is a first step toward reducing ambiguity in the evaluation of adverse drug reactions.

Documentation↗
PubMed1976

Adverse drug reactions-a matter of opinion.

The accurate identification of adverse drug reactions (ADRs) is difficult because ADRs usually present no unique clinical or laboratory findings that demarcate them from the manifestations of concurrent illnesses. The identification of ADRs depends on the clinical assessments of physicians-sometimes the clinician treating the patient and at other times a clinical pharmacologist. Considering the complex and subjective nature of clinically identifying ADRs, how accurately are ADRs identified? To answer this question, three clinical pharmacologists each independently evaluated 60 selected cases to determine if medication, alcohol, or "recreational" drugs had caused the hospitalization. The three clinical pharmacologists agreed on only 30 cases (50%), and 27 of these were thought to be unrelated to medications. In 19 of the 30 cases about which the clinical pharmacologists disagreed, they disagreed on whether or not a medication-or alcohol-related event had occurred at all. The clinical pharmacologists disagreed with the physicians treating the patient in 22% to 37% of the cases, but because of the differences among the pharmacologists, the treating physicians agreed with at least one of them in 95% of the cases. Complete agreement between the clinical pharmacologists and the treating physicians occurred in 47% of the cases. This degree of disparity in the clinical identification of ADRs shows that the evaluation of ADRs is subjective and imprecise. The accurate identification of ADRs awaits the development of an objective technique for recognizing ADRs.

Alcoholic Intoxication↗
PubMed1976

Effect of halofenate on serum thyroid hormone determinations in vitro.

Halofenate has been shown to decrease thyroxine (T4) binding to thyroxine-binding globulin (TBG) in vitro. Several indirect serum thyroid hormone assays are dependent on thyroid hormone binding and the results might be altered by halofenate in the serum. Halofenate free acid (50-500 mug/ml) was added to serum samples in vitro, and the samples were assayed for total serum T4 by competitive protein-binding assay (CPB) and radioimmunoassay (RIA), the per cent of dialyzable T4 (%FT4), total serum triiodothyronine (T3) by RIA, and resin T3 uptake (RT3U). Halofenate increased the measured T4 (CPB), %FT4, T3 (RIA), AND RT3U, but did not alter the T4 (RIA) determination. Thus, halofenate appears to diminish T4 binding to TBG in vitro, and artifactually alters the serum determinations of T4 (CPB), %FT4, T3 (RIA), AND RT3U. Calculated values derived from these measurements for the free thyroxine index and "free" T4 will also be affected halofenate. Only the T4 (RIA) determination was unchanged by the presence of halofenate in vitro.

Antigens↗
PubMed1975

Adverse drug reactions. A critical review.

The data on adverse drug reactions (ADRs) are incomplete, unrepresentative, uncontrolled, and lacking in operational criteria for identifying ADRs. No quantitative conclusions can be drawn from the reported data in regard to morbidity, mortality, or the underlying causes of ADRs, and attempts to extrapolate the available data to the general population would be invalid and perhaps misleading. To evaluate the impact as well as the causes of ADRs, representative populations, including general hospital and ambulatory patients of all medical specialties, must be studied, and operationally defined criteria must be used to establish the presence of an ADR in a prospective study that incorporates appropriate control populations. Similar studies on the benefits of drug use are needed to provide perspective on the risk-benefit aspects of drug therapy. Until such studies are performed, estimates of the nature and scope of the ADR problem can be only guesses.

Anti-Bacterial Agents↗