John L. Colaizzi

Food interaction and steady-state pharmacokinetics of itraconazole capsules in healthy male volunteers.

The influence of food on itraconazole pharmacokinetics was evaluated for 27 healthy male volunteers in a single-dose (200 mg) crossover study with capsules containing itraconazole-coated sugar spheres. This study was followed by a study of the steady-state pharmacokinetics for the same subjects with 15 days of administration of itraconazole at 200 mg every 12 h. Concentrations of itraconazole and hydroxyitraconazole, the active main metabolite, were measured in plasma by high-performance liquid chromatography. The results of the food interaction segment showed that a meal significantly enhances the amount of itraconazole absorbed. The mean maximum concentration in plasma of unmetabolized itraconazole after fasting (140 ng/ml) was about 59% that after the standard meal (239 ng/ml). The rate of elimination was not affected (terminal half-life, approximately 21 h). The mean maximum concentration in plasma of hydroxyitraconazole after fasting was about 72% the postmeal concentration (287 and 397 ng/ml, respectively). The terminal half-life of hydroxyitraconazole was approximately 12 h. Steady-state concentrations of itraconazole and hydroxyitraconazole were reached after 14 or 15 days of daily dosing. The average steady-state concentrations were approximately 1,900 ng/ml for itraconazole and 3,200 ng/ml for hydroxyitraconazole. The shape of the elimination curve for itraconazole after the last dose was indicative of saturable elimination. This conclusion was confirmed by the sevenfold increase in the area under the curve from 0 to 12 h at steady state compared with the area under the curve from 0 h to infinity after a single dose. It was furthermore confirmed by the larger-than-expected number of half-lives required to achieve steady-state plasma drug levels.

Cisapride: A Gastrointestinal Prokinetic Drug:

OBJECTIVE: To summarize the pharmacology, pharmacokinetics, efficacy, and safety of cisapride, and to evaluate its potential therapeutic role. DATA SOURCES: A computerized search of the MEDLINE database was used to identify English-language publications of cisapride data in humans. The MEDLINE search was supplemented by review article bibliographies. There was no attempt to limit the search to a specific gastrointestinal motility disorder. STUDY SELECTION: The MEDLINE search alone identified 165 citations. Because of the volume of available human cisapride data, the focus of the efficacy section is on complete published reports of controlled clinical studies. Abstracts and uncontrolled data are discussed only when other information is unavailable to address important aspects. DATA EXTRACTION: Information regarding study design, study population, results, and safety was recorded from each publication. The placebo response to gastrointestinal complaints in patients with motility disorders is high. Therefore, objective evidence of improvement was emphasized when documentation was available. DATA SYNTHESIS: Cisapride stimulates the motility of smooth muscle lining the esophagus, stomach, small intestine, and colon, and increases the tone of gut sphincters in vitro and in vivo. In controlled investigations, cisapride was superior to placebo in relieving symptoms associated with reflux esophagitis, nonulcer dyspepsia, and gastroparesis. Similar symptom and healing effects were observed with cisapride and histamine (H)2-antagonists in reflux esophagitis. Cisapride was either equal to or superior to metoclopramidein relieving reflux symptoms. However, metoclopramide was associated with significantly more central nervous system adverse effects. Cisapride was well tolerated, with adverse effects limited primarily to the gastrointestinal tract. CONCLUSIONS: Cisapride represents an attractive alternative to metoclopramidefor the treatment of a variety of motility disorders. Because it addresses a primary underlying cause of reflux esophagitis, cisapride may also prove to be an effective alternative to acid suppressants in the management of this disorder.

Food Interaction and Steady-State Pharmacokinetics of Itraconazole Oral Solution in Healthy Volunteers

Study Objectives. To evaluate the effect of food on the bioavailability of itraconazole (ITR) hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) solution under multiple‐dose to steady‐state conditions, and to determine the pharmacokinetics of ITR solution at steady state.

Pharmacokinetics and Dose Proportionality of Domperidone in Healthy Volunteers

Domperidone is a potent gastrokinetic agent and antinauseant currently undergoing clinical trials in the United States. The bioequivalence of 20 mg of domperidone given as free‐base tablets and maleate salt tablets, and the bioavailability of base and maleate tablets relative to a solution, were studied in 21 fasting men using a crossover design. Plasma samples collected for up to 48 hours were analyzed for domperidone levels, using a sensitive and specific radioimmunoassay (RIA). The absorption of domperidone was very rapid, with mean peak plasma concentration (Cmax) values of 18.8, 15.0, and 20.7 ng/mL attained at 0.9, 1.2, and 0.6 hours after the administration of base tablet, maleate tablet, and solution, respectively. The mean elimination half‐life (t1/2) ranged from 12.6 to 16.0 hours. The mean oral clearance (CL/F) after the solution dose was 4,735 ± 2,017 mL/min and the mean apparent volume of distribution (Vd/F) was 6,272 ± 5,100 L, indicating an extensive distribution of domperidone in the body. The area under the plasma concentration‐time curve (AUC) data demonstrated bioequivalence of base and maleate tablets. The relative bioavailability for base tablet and maleate tablet was 107 ± 50% and 116 ± 47%, respectively, of that of the solution. Dose proportionality of domperidone was also studied in 12 subjects at solution doses of 10, 20, and 40 mg. Linear correlations between the dose and Cmax and AUC values were observed. Mean CL/F remained relatively constant after doses of 10, 20, and 40 mg (5,255 ± 3,159, 4,842 ± 1,774, and 4,380 ± 1,289 mL/min, respectively), indicating linear pharmacokinetics of domperidone over the dose range studied.

Effect of altered urinarypH on tetracycline and doxycycline excretion in humans

The effect of altered urinary pH on the excretion of single doses of orally administered tetracycline hydrochloride and doxycycline hyclate was studied in humans. Alkalinization of the urine significantly enhanced the cumulative renal excretion of both tetracycline and doxycycline as compared to acidic urine treatments. Altered tubular reabsorption was assumed to have caused this effect, since tetracyclines have been shown to be more lipid soluble at their isoelectric pH (approximately the pH of the acidic urine treatment) as compared to more alkaline pHs. The renal clearance of doxycycline was significantly increased by urinary alkalinization.

Comparative Dissolution Performance of Internationally Available Piroxicam Products

Piroxicam is a widely used nonsteroidal antiinflammatory drug available worldwide under various trade names by several manufacturers. Only one brand of piroxicam (Feldene) is currently marketed in the U.S., and the United States Pharmacopeial Convention established an official dissolution requirement for piroxicam in 1985. The purpose of this study was to evaluate and compare the dissolution performance of several internationally available piroxicam products using the United States Pharmacopeia (USP) dissolution test for piroxicam capsules. Of 25 brands of piroxicam capsules evaluated, 72 percent of the brands failed to meet the USP requirement, several by a wide margin. Although there is no specific USP dissolution test for tablets, the test for capsules was applied to five different brands of piroxicam tablets, and 80 percent of the tablet brands tested failed to meet the USP requirement. Although comparative bioavailability studies would be required to establish any definitive relationship between dissolution test performance and bioavailability, the failure of most of these products to meet the USP requirement for dissolution indicates formulation differences that could result in altered bioavailability. The substantial differences in dissolution performance observed among the piroxicam oral dosage forms tested have implications concerning the equivalency and standards of multisource products available on the international market, and should be taken into account by health care providers worldwide.

Safety evaluation of ritanserin: an investigational serotonin antagonist

Ritanserin is an investigational serotonin-S2 receptor antagonist with activity in a variety of psychiatric disturbances characterized by dysthymia or anxiety. This investigation evaluates acute safety and tolerability of ritanserin in 12 healthy males. Ritanserin 10 mg, 20 mg, and placebo were administered as single doses in a randomized, double-blind, crossover fashion. Treatment effects on vital signs, laboratory tests, a mood evaluation test, electrocardiograms (ECGs), and reported adverse experiences were monitored. Plasma levels were determined at two hours postdose. Results indicated no clinically relevant effects on vital signs, laboratory tests, ECGs, or mood evaluations. Dose proportionality was demonstrated. The incidence of total adverse effects (primarily somnolence and fatigue) after single-dose administation was 25 percent for placebo, 75 percent for 10 mg, and 81.8 percent for 20 mg. There was a relationship between incidence of adverse effects and dose, but no general correlation between plasma levels and severity of adverse experiences. The results indicate that ritanserin is safe and tolerable following acute administration of 10 mg and 20 mg oral doses.

The generic drug scandal and its implications for pharmacy professionals

The current furor surrounding the generic drug approval process adds to the continuing debate over generic drug products

Critical Evaluation of Thioridazine Bioequivalence

The phenothiazines have exhibited a history of problems associated with the bioequivalence of solid oral dosage forms. The more recent availability of chemically equivalent forms of thioridazine has raised new and interesting questions about the appropriateness of generic product interchange, even among brands that have been designated “therapeutically equivalent” by the Food and Drug Administration. The scrutiny that has accompanied the consideration of thioridazine products for inclusion into various state generic substitution formularies has offered an opportunity to examine issues involving bioequivalency in considerable detail. Specific bioequivalency concerns relate to: Correct analysis of drug in biological fluids; the importance of evaluating active metabolites; single-dose vs. multiple-dose crossover studies; appropriate statistical power analysis; the “70/70” rule, and comparison of product variabilities. Examples of problems are cited to illustrate that significant questions still remain about the appropriate factors that should be used to establish bioequivalency.

The PharmD/MD Dual-Degree Program and Its Potential Value in the Pharmaceutical Industry

The first dual-degree program combining both the doctor of pharmacy (PharmD) and the doctor of medicine (MD) degrees was designed and launched by Rutgers, The State University of New Jersey, in academic year 2013-2014. This joint effort was led by the Ernest Mario School of Pharmacy (EMSOP) and the Robert Wood Johnson Medical School (RWJMS) to combine expertise in both diagnostic and treatment facets of health care and to prepare graduates for leadership roles in providing and managing comprehensive patient care in a variety of settings. One area of potential value of these skill sets is the drug development industry. A survey was conducted among pharmaceutical executive stakeholders associated with a postdoctoral training program to assess the perceived value of this new dual-degree skill set and to identify particular functions where the combined training has its best fit. Results indicate that the combined nature of this training is highly valued in this setting, especially in the areas of clinical pharmacology, drug safety and pharmacovigilance, medical affairs/strategy, and medical science liaisons. Future monitoring of graduates will further define the value of this dual degree in this and other health care settings.