Search PubMed⌕ Search

Biomedical subjects

T C Hardin

Publications and source records attributed to T C Hardin.

At least 37 records · Page 2Linked to original sources
PubMed1989

A prospective double-blind trial of intracorporeal papaverine versus prostaglandin E1 in the treatment of impotence.

A randomized prospective, double-blind clinical trial was performed comparing intracorporeal injections of papaverine (30 mg. per ml.) with prostaglandin E1 (10 mcg. per ml.) as pharmacological treatment of impotence. A total of 15 men completed the study, receiving papaverine and prostaglandin E1 in a crossover design. Over-all, 9 of 15 evaluable patients had a full erection with either 1 or both drugs: 3 secondary to papaverine only, 2 to prostaglandin E1 only, and 4 to both drugs. No major complications were observed. We conclude that intracorporeal prostaglandin E1 may be used successfully to stimulate pharmacological erections and that it might be useful in patients not responding to intracorporeal papaverine.

Adult↗
PubMed1988

Pharmacokinetics of itraconazole following oral administration to normal volunteers.

The pharmacokinetics of itraconazole, an orally effective, broad-spectrum, systemic antifungal agent, were evaluated in five healthy male volunteers. Each subject was studied on days 1 and 15 at the following dosages: 100 mg once daily (regimen A), 200 mg once daily (regimen B), and 200 mg twice daily (regimen C). On each study day, itraconazole was administered with a standardized meal. Plasma samples were collected for 72 h postdose, and 24-h urine specimens were obtained. On day 1 of regimen C, plasma samples were collected following the second dose. Samples were assayed for itraconazole by a sensitive, reverse-phase, high-performance liquid chromatography method. Wide intersubject variations in itraconazole concentration in plasma versus time profiles were observed on all study days. Absorption appeared to be slow, with day 1 mean peak itraconazole concentrations in plasma of 110 ng/ml at 2.8 h (regimen A), 272 ng/ml at 3.0 h (regimen B), and 553 ng/ml at 3.4 h (regimen C). Mean peak itraconazole concentrations in plasma on day 15 were 412 ng/ml at 3.0 h (regimen A), 1,070 ng/ml at 4.4 h (regimen B), and 1,980 ng/ml at 6.0 h (regimen C). The steady state was achieved by day 13. Respective elimination half-lives on days 1 and 15 were 15 and 34 h (regimen A), 20.7, and 36.5 h (regimen B), and 25 and 41.7 h (regimen C), respectively. The areas under the plasma concentration versus time curves (0 to infinity) on day 1 were 1,320 (regimen A), 4,160 (regimen B), and 12,600 ng.h/ml (regimen C). With the exception of one patient on day 15 of regimen C, itraconazole was not detected in the urine. All data support dose-dependent pharmacokinetic behavior for itraconazole.

Administration, Oral↗
PubMed1986

Rapid replacement of serum albumin in patients receiving total parenteral nutrition.

The albumin deficit (AD) of 13 malnourished patients with serum albumin concentrations (SAC) of less than 3.0 grams per deciliter was estimated using a simple equation. The AD was replaced over a period of 24 to 72 hours as a component of the formulation of total parenteral nutrition (TPN). AD was estimated assuming a volume of distribution of 3 deciliters per kilogram of actual body weight and a minimum acceptable SAC of 3.5 grams per deciliter. The mean AD was 200 +/- 94 grams (mean +/- standard deviation), the average dose administered was 206 +/- 97 grams. TPN regimens provided 42.0 +/- 8.5 nonprotein kilocalories per kilogram with a nonprotein calorie to nitrogen ratio of 125 to 150:1. The SAC increased from 2.36 +/- 0.38 grams per deciliter to 3.46 +/- 0.26 grams per deciliter immediately after replacement. At follow-up study, the SAC at 6.4 +/- 1.5 days yielded a SAC value of 3.35 +/- 0.30 grams per deciliter, indicating no significant decrease from immediate replacement values. AD can be easily estimated, rapidly replaced and maintained with adequate nutritional support.

Adult↗
PubMed1983

Latamoxef (moxalactam) kinetics in volunteers studied by a specific HPLC assay technique.

Pharmacokinetic parameters were calculated from plasma and urine latamoxef ('Moxalactam') levels determined by HPLC assay after single and multiple intramuscular (im) and single intravenous (iv) doses of 500 mg given to eight healthy volunteers. After im administration, systemic bio-availability was 92% after both the first and sixth doses. Peak plasma concentration was 18 mg/l (first dose) and 22 mg/l (sixth dose), reached at 1.2 h and 1.3 h respectively. The terminal phase half-lives were 2.5 h and 2.7 h respectively. After iv administration, the initial phase plasma half-life was 0.23 h and the terminal phase half-life, 2.4 h. Plasma clearance was 87.0 ml/min. The steady state distribution volume was 210 ml/kg. After iv administration, 72% of the dose was found in the urine in the first 24 h. Urinary clearance was 66 ml/min (iv dose) and 63 ml/min (sixth im dose). Most systemic infections will permit eight hourly dosing with 500 mg im or iv. Many urinary infections will be best treated with im administration, rather than iv administration.

Adult↗
PubMed1981

Determination of moxalactam in human body fluids by liquid chromatographic and microbiological methods.

High-performance liquid chromatographic methods for determination of the isomers of moxalactam in plasma and urine have been developed. Conventional reverse-phase chromatography was used for plasma assays, and an ion-pairing reagent was included for urine assays. Detection limits were 1.5 micrograms/ml of plasma and 7.5 micrograms/ml of urine. The high-performance liquid chromatographic assays were extensively compared with a microbiological assay (detection limit, 1 microgram/ml), using samples from human volunteers to whom moxalactam had been administered as well as plasma and urine from untreated humans, to which moxalactam was added. The correlations between the assays were quite good, but the precision and accuracy of the high-performance liquid chromatographic methods were superior. Both types of assays were used in a study of the stability of moxalactam-containing samples at various temperatures.

Biological Assay↗
PubMedDate not supplied

Compatibility of 5-fluorouracil and total parenteral nutrition solutions.

The physicochemical stability and availability of 0.1% 5-fluorouracil solutions in D5W and a typical total parenteral nutrition solution (hypertonic dextrose and crystalline amino acids) were studied in both glass and Viaflex delivery systems. Serial samples collected over a 48-hour period were assayed for 5-fluorouracil concentration using a high performance liquid chromatographic technique. Changes in the pH as well as precipitate formation were also investigated. There was no reduction in the amount of 5-fluorouracil at 48 hours in either the glass or plastic system, regardless of whether the drug was added to D5W or to the total parenteral nutrition solution. No pH changes or precipitates were observed. These findings indicate that 5-fluorouracil is compatible with and available from total parenteral solutions of hypertonic dextrose and amino acid in both plastic and glass containers. Use of such a system would allow for (1) a reduction in vascular access in patients receiving both treatments and (2) continued administration of nutritional support without the requirement for additional fluid volume.

Amino Acids↗
PubMedDate not supplied

Nutritional parameters observed during 28-day infusion of recombinant human tumor necrosis factor-alpha.

In conjunction with a Phase I investigation of the antineoplastic activity of recombinant human tumor necrosis factor-alpha (TNF-alpha), administered as a 28-day continuous infusion, selected nutritional parameters were evaluated to identify any effect that might be attributed to the TNF infusion. Seven clinically stable men with a variety of tumor types were studied. None had clinical or laboratory evidence of significant malnutrition before entry into the study. Five patients received 10 micrograms of recombinant human TNF-alpha per square meter per day and two patients received 25 micrograms/m2 per day. Indirect calorimetry assessment of resting energy expenditure, body weight, serum TNF concentration, and laboratory analysis of common nutritional markers (albumin, prealbumin, and triglycerides) were performed at baseline, day 14, day 28, and 2 weeks (day 42) after completion of the infusion. There were no statistically significant differences by analysis of variance observed in any parameter during the study period compared with baseline values and values on day 42. Also, there were no differences between any parameters when stratified by dose administered, although the number of patients studied was small. Measured serum TNF concentrations ranged from 0.02 to 1.56 ng/mL and did not correlate with study day or dose of TNF infused. No correlation was observed between serum TNF concentrations and resting energy expenditure. Although others have reported significant metabolic changes associated with acute administration of TNF in humans and animals, our experience does not support a hypermetabolic state in patients receiving low daily dose, long-term (28-day) continuous infusion of recombinant human TNF-alpha, a state that may be consistent with many neoplastic conditions.

Adult↗
PubMedDate not supplied

Hyperlipidemia associated with protease inhibitor therapy.

OBJECTIVE: To report a case of extreme hyperlipidemia associated with protease inhibitor-based antiretroviral therapy and review the relevant literature concerning lipid abnormalities with HIV infection and antiretroviral therapy. CASE SUMMARY: A 35-year-old HIV-infected man developed a serum cholesterol of 1472 mg/dL and fasting serum triglycerides of 8660 mg/dL after initiation of antiretroviral therapy consisting of ritonavir, saquinavir, nevirapine, and didanosine. All other medications had been stable during this time period and the abnormality resolved after discontinuation of antiretroviral therapy and initiation of lipid-lowering therapy. The elevated cholesterol and triglyceride concentrations did not recur when therapy was reinstituted with nelfinavir, saquinavir, nevirapine, and didanosine. The hyperlipidemia then was attributed to ritonavir. DISCUSSION: Lipid abnormalities are common in patients with HIV infection and usually consist of hypocholesterolemia and moderate hypertriglyceridemia. Hypercholesterolemia and hypertriglyceridemia have been reported with ritonavir and, less commonly, with other currently available protease inhibitors. Some cases of ritonavir-associated hyperlipidemia have been extreme. Although an association between hyperlipidemia and clinical consequences such as pancreatitis and atherosclerotic disease has not been well described with protease inhibitor therapy, pancreatitis is common in HIV-infected patients. It is possible that in some cases, protease inhibitor-induced hypertriglyceridemia may contribute to the development of pancreatitis. CONCLUSIONS: Optimal management of lipid abnormalities in HIV-infected patients is controversial. The potential benefit of reducing the incidence of pancreatitis and atherosclerotic events must be weighed against the risk of intolerance, toxicity, and drug interactions.

Adult↗
PubMedDate not supplied

Cefepime.

Cefepime is a potent, broad-spectrum, fourth-generation cephalosporin with enhanced activity against most gram-positive aerobic bacterial pathogens and many gram-negative aerobic bacteria that are resistant to other cephalosporins. The drug's zwitterionic structure contributes to more rapid penetration of gram-negative bacterial cell membranes, and its low affinity for most type I beta-lactamases leads to significantly reduced enzymatic degradation compared with other cephalosporins. Cefepime has a good toxicity profile, with minor gastrointestinal and central nervous system symptoms being most prevalent. At dosages ranging from 1-2 g every 8-12 hours, it is an alternative option for infections of the lower respiratory tract, urinary tract, and skin and skin structures, as well as febrile episodes in neutropenic patients with cancer, and bacteremia or septicemia in critically ill patients.

Anti-Bacterial Agents↗
PubMedDate not supplied

Comparison of ampicillin-sulbactam and ticarcillin-clavulanic acid in patients with chronic renal failure: effects of differential pharmacokinetics on serum bactericidal activity.

STUDY OBJECTIVES: To evaluate the pharmacodynamic antibacterial activity of ticarcillin-clavulanic acid (T-C) and ampicillin-sulbactam (A-S) combinations against reference bacterial strains in patients with end-stage renal disease maintained on long-term hemodialysis. DESIGN: Randomized, crossover, controlled study. SETTING: National Institutes of Health-funded general clinical research unit in a Veterans Administration Medical Center. PATIENTS: Nine adult men with end-stage renal disease maintained on long-term hemodialysis. Two subjects did not complete the study due to problems of vascular access, and another withdrew for personal reasons. INTERVENTIONS: On a nondialysis day, each subject was randomly administered either T-C 3.1 g or A-S 3 g as a slow intravenous infusion over 30 minutes. Serial blood samples were collected for measurement of antibiotic serum concentrations and determination of serum bactericidal titers. Following a washout period, the study was repeated with the alternative antibiotic combination. MEASUREMENTS AND MAIN RESULTS: The mean observed apparent beta-half-life of clavulanic acid was substantially shorter than that for the other three drugs. The bactericidal activity of both A-S and T-C against non-beta-lactamase-producing (N beta-LP) strains of S. aureus and E. coli was consistently high, as indicated by geometric mean SBTs of at least 1:5 at 24 hours. Against beta-lactamase-producing (beta-LP) S. aureus, the geometric mean SBTs for A-S were at least 1:25 throughout the study period, while the geometric mean SBTs for T-C decreased over 24 hours from 1:29 to 1:6. Against beta-LP E. coli, the bactericidal activities for both A-S and T-C were poor, with geometric mean peak SBTs of only 1:6 and 1:3, respectively. The geometric mean SBT for T-C against this E. coli strain had declined to 1:1 at 6 hrs. CONCLUSION: Increasing the dosing interval for T-C in patients with end-stage renal disease may lead to periods of insufficient clavulanic acid to protect ticarcillin from beta-lactamase degradation.

Adult↗