摘要:

Clinical Pharmacology and Therapeutics(1986)40,483–487; doi:10.1038/clpt.1986.2

ISSN:0009-9236    

DOI:10.1038/clpt.1986.212

年代:1986

数据来源: WILEY

摘要:

Beginning with the class graduating June 1984, Dartmouth Medical School introduced a required clinical pharmacology course. Approximately 89% of the fourth‐year students felt that the course was “essential” to their future careers as physicians. As interns, 80% found the course frequently useful or essential during their internships; 84% felt that they were either slightly or much better prepared than their fellow interns with respect to their therapeutic knowledge and skills. Average student performance on a pretest (33% correct answers) improved dramatically on a posttest (87% correct; P<0.001). Finally, although student performance on all sections of Part II of the national board examinations showed statistically nonsignificant trends toward improvement (from the 48th to the 52nd percentile), performance on questions testing core concepts in clinical pharmacology improved from the 38th percentile to the 74th percentile (P<0.0001). This required fourth‐year course in clinical pharmacology was evaluated favorably by our students and resulted in objective improvement in their therapeutic knowledge and skills.Clinical Pharmacology and Therapeutics(1986)40,488–493; doi:10.1038/clp

ISSN:0009-9236    

DOI:10.1038/clpt.1986.213

年代:1986

数据来源: WILEY

摘要:

This work was done to determine the reasons for variation in the reported rates—ranging from50%—of sensitivity to aspirin and cross‐reactivity to acetaminophen and ibuprofen. In 47 studies that reported rates of sensitivity and in 23 reports that contained series of sensitive patients, we examined the research setting, source of patients, clinical attributes of the study group, admission process, and selection, operational definition, and method of determining sensitivity reactions. In five studies with reasonably well‐specified methods, the reported sensitivity rates to aspirin were lowest (0.3% to 0.9%) for patients without allergic tendencies, higher in asthmatics, and highest if patients had nasal polyps or severe atopy. Although not determined in any of these studies, the rate of sensitivity in a general (nonclinical) population would doubtlessly be substantially lower than the rate of three per 1000 reported for nonallergic patients. The admixture of different clinical groups, varying definitions, and ascertainment of a sensitivity reaction seem to be responsible for the variations in the reported rates of sensitivity and cross‐reactivity.Clinical Pharmacology and Therapeutics(1986)40,494–505; doi:10.1038/c

ISSN:0009-9236    

DOI:10.1038/clpt.1986.214

年代:1986

数据来源: WILEY

摘要:

Caffeine and theophylline block the vasodilating effects of adenosine and may act to enhance sympathoadrenal discharge and activate the renin‐angiotensin system. To determine if these methylxanthines might thereby have effects on regional blood flow, we studied the influence of caffeine and theophylline on apparent liver plasma flow (LPF) in normal subjects as assessed by indocyanine green clearance. Oral caffeine, 250 mg, reduced LPF by 19% from 630 ± 150 to 510 ± 120 ml/min (P<0.001). Intravenous theophylline (4.3 mg/kg) reduced LPF by 15% from 550 ± 50 to 470 ± 90 ml/min (P<0.05). These methylxanthine‐induced falls in LPF may alter the disposition of concomitantly administered drugs. Because of their widespread use in Western society, caffeine and theophylline may be major determinants of liver blood flow in the general population. They may therefore prolong the t1/2and increase steady‐state levels of hepatically eliminated drugs.Clinical Pharmacology and Therapeutics(1986)40,506–510; doi:10.1038/c

ISSN:0009-9236    

DOI:10.1038/clpt.1986.215

年代:1986

数据来源: WILEY

摘要:

Quinidine and quinine are stereoisomers. When given sequentially or simultaneously, the renal clearance of values of quinidine and quinine were measured in seven healthy volunteers and when given simultaneously, to an additional five elderly men. Analytic specificity was provided by an HPLC drug assay. Protein binding was measured by equilibrium dialysis. The quinidine clearance exceeded the quinine clearance in every individual. The mean (±SD) ratio of these clearances was 4.2 ±1.4 when the drugs were given together and 4.4 ± 2.3 when they were given separately in the younger subjects and 3.4 ± 0.5 when given simultaneously to the elderly. Calculating clearance of drug in serum water (unbound drug clearance) revealed a quinidine clearance of 6.1 ± 2.3 times that of creatinine measured simultaneously, and for quinine it was 1.5 ± 0.6 times that of creatinine. We conclude that there is stereoselective net renal tubular secretion of quinidine over quinine indicating stereoselectivity of this renal tubular transport process.Clinical Pharmacology and Therapeutics(1986)40,511–517; doi:10.1038/clpt.

ISSN:0009-9236    

DOI:10.1038/clpt.1986.216

年代:1986

数据来源: WILEY

摘要:

Two elderly patients, who were chronically receiving aspirin, developed lethargy, incontinence, and confusion after dosing with acetazolamide. Unbound plasma acetazolamide concentrations were elevated and plasma protein binding was reduced, suggesting an interaction with aspirin. In vitro studies demonstrated a concentration‐dependent effect of salicylate on acetazolamide binding to serum proteins. At a therapeutic serum acetazolamide level of 8.0 µg/ml, the unbound percentage of acetazolamide in serum was 3.3% and increased to 11.0% and 30.0%, with serum salicylate levels of 200 and 386 µg/ml, respectively. Furthermore, the apparent association constant of acetazolamide for binding to serum proteins was decreased by 58% and 86% of its control value at these respective salicylate concentrations. The maximal binding capacity of serum for acetazolamide was not affected by salicylate. Pharmacokinetic studies in four volunteers showed that the plasma protein binding and renal clearance of acetazolamide were significantly reduced during chronic salicylate dosing. Salicylate appears to competitively inhibit the plasma protein binding of acetazolamide and simultaneously to inhibit acetazolamide renal tubular secretion. Caution is advised when acetazolamide and salicylate are used concurrently.Clinical Pharmacology and Therapeutics(1986)40,518–524; doi:10.1038/clpt.19

ISSN:0009-9236    

DOI:10.1038/clpt.1986.217

年代:1986

数据来源: WILEY

摘要:

The effect of the selective α1‐antagonist terazosin on serum lipoproteins and certain blood pressure–regulating factors was assessed in 15 patients with essential hypertension. Terazosin given during 8 weeks reduced arterial pressure (from 153/103 ± 3/2 (SE) to 143/96 ± 5/2 mm Hg; P<0.02) but did not modify body weight, heart rate, blood volume, plasma renin activity, aldosterone and catecholamine levels, or serum cholesterol, triglycerides, and their lipoprotein fractions. In nine of the patients, blood pressure control was not achieved with terazosin monotherapy and the diuretic methyclothiazide, 2.5 mg, was added. After 8 weeks of combined treatment, blood pressure decreased further (P<0.05); serum lipids and lipoprotein fractions did not change as compared with placebo or terazosin conditions. These findings indicate that terazosin in monotherapy does not unfavorably influence lipid metabolism.Clinical Pharmacology and Therapeutics(1986)40,525–530; doi:10.1038/clpt

ISSN:0009-9236    

DOI:10.1038/clpt.1986.218

年代:1986

数据来源: WILEY

摘要:

Nine healthy volunteers received a single oral dose of 200 mg spironolactone, once during fasting conditions and once immediately after a standardized breakfast. Serum concentrations of spironolactone and its metabolites 7α‐thiomethylspirolactone, 6β‐hydroxy‐7α‐thiomethylspirolactone, and canrenone were determined by HPLC for 24 hours after dosing. By taking spironolactone with food, the mean (± SD) AUC (0 to 24 hours) of the parent drug increased from 288 ± 138 (empty stomach) to 493 ± 105 ng · ml−1· hr (P<0.001). The AUC (0 to 24 hours) of the three metabolites together also increased significantly from 8511 ± 2062 (empty stomach) to 11219 ± 2471 ng · ml−1· hr (P<0.01). The mean (±SD) percent increase in AUC (0 to 24 hours) of spironolactone when it was given with food, compared with the ingestion on an empty stomach (95.4% ± 66.9%), was much more pronounced than the corresponding increase of 7α‐thiomethylspirolactone (45.4% ± 33.7%), 6β‐hydroxy‐7α‐thiomethylspiro‐lactone (21.8% ± 21.5%), and canrenone (40.7% ± 26.3%). These observations indicate that food promotes the absorption of spironolactone and possibly decreases its first‐pass metabolism.Clinical Pharmacology and Therapeutic

ISSN:0009-9236    

DOI:10.1038/clpt.1986.219

年代:1986

数据来源: WILEY

摘要:

In a placebo‐controlled, double‐blind study we evaluated the ability of a single 50 mg oral dose of nalmefene to block the effects of intravenous opioid challenge (2 µg/kg fentanyl). Fentanyl‐induced respiratory depression (CO2responsiveness), analgesia (tourniquet ischemia), and subjective effects were totally blocked for 48 hours and showed only minimal breakthrough 72 hours after nalmefene. Plasma concentration‐time data for nalmefene indicate good oral bioavailability and a prolonged terminal elimination phase (mean t1/211.1 hours). These findings suggest that nalmefene could provide prolonged effectiveness in limiting emergence of opioid effects during addiction therapy.Clinical Pharmacology and Therapeutics(1986)40,537–542; doi:10.1038/cl

ISSN:0009-9236    

DOI:10.1038/clpt.1986.220

年代:1986

数据来源: WILEY

摘要:

Eighteen healthy volunteers, selected according to their ability to oxidize sparteine, took single oral doses of 100 mg imipramine and desipramine. For imipramine the following clearances (L · min−1) were found in six rapid extensive metabolizers (EM), six slow EM, and six poor metabolizers (PM), respectively (mean and range): apparent oral clearance: 2.55 (1.39 to 3.47), 2.28 (1.18 to 4.26), and 1.35 (0.96 to 1.64). Clearance via demethylation was: 1.42 (0.61 to 2.01), 1.60 (0.78 to 3.81), and 1.09 (0.76 to 1.64); clearance via other pathways was: 1.13 (0.74 to 1.75), 0.69 (0.40 to 1.59), and 0.26 (0 to 0.46). For desipramine the apparent oral clearance (L · min−1) was 0.19 (0.12 to 0.24) in PM compared with 1.64 (1.46 to 1.80) and 1.03 (0.77 to 1.13) in rapid EM and slow EM. Extremely long elimination t1/2s of desipramine were seen in PM: 81 to 131 hours compared with 13 to 23 hours in EM. 2‐OH‐imipramine and 2‐OH‐desipramine were detectable in plasma of only the 12 EM, where the ratio‐to‐parent compound was higher in rapid EM than in slow EM. This study confirms that 2‐hydroxylation of imipramine and desipramine depends almost exclusively on the sparteine oxygenase, whereas the demethylation of imipramine depends mainly on a different isozyme.Clinical Pharmacology and Therapeutics(1986)40,543–549; doi

ISSN:0009-9236    

DOI:10.1038/clpt.1986.221

年代:1986

数据来源: WILEY