Anabolic steroids in COPD: a review and preliminary results of a randomized trial

Patients with severe chronic obstructive pulmonary disease (COPD) commonly develop weight loss, muscle wasting, and consequently poor survival. Nutritional supplementation and anabolic steroids increase lean body mass, improve muscle strength, and survival in patients enrolled in comprehensive rehabilitation programs. Whether anabolic steroids are effective outside an intensive rehabilitation program is not known. We conducted a prospective, double-blind, placebo-controlled, 16-week trial to study the benefits of anabolic steroids in patients with severe COPD who did not participate in a structured rehabilitation program. Biweekly intramuscular injections of either the drug (nandrolone decanoate) or placebo were administered. Sixteen patients with severe COPD were randomized to either placebo or nandrolone decanoate. The placebo group weighed 55.32 ± 11.33 kg at baseline and 54.15 ± 10.80 kg at 16 weeks; the treatment group weighed 68.80 ± 6.58 at baseline and 67.92 ± 6.73 at 16 weeks. Lean body mass remained unchanged, 71 ± 6 vs. 71 ± 7 kg in placebo group and 67 ± 7 vs. 67 ± 7 in treatment group, at baseline and 16 weeks respectively. The distance walked on 6 min was unchanged at baseline, 8 weeks, and 16 weeks in placebo (291.17 ± 134.83, 282.42 ± 115.39, 286.00 ± 82.63 m) and treatment groups (336.13 ± 127.59, 364.83 ± 146.99, 327.00 ± 173.73 m). No improvement occurred in forced expiratory volume in one second, forced vital capacity, maximal inspiratory pressure, maximal expiratory pressure, VO2 max or 6-min walk distance or health related quality of life. Administration of anabolic steroids (nandrolone decanoate) outside a dedicated rehabilitation program did not lead to either weight gain, improvement in physiological function, or better quality of life in patients with severe COPD.

Pharmacokinetics of total and unbound ertapenem in healthy elderly subjects

Ertapenem is a new once-a-day parenteral carbapenem antimicrobial agent. The pharmacokinetics of unbound and total concentrations of ertapenem in plasma were investigated in elderly subjects and compared with historical data from young adults. In a single- and multiple-dose study, healthy elderly males and females (n = 14) 65 years old or older were given a 1-g intravenous (i.v.) dose once daily for 7 days. Plasma and urine samples collected for 24 h on days 1 and 7 following administration of the 1-g doses were analyzed by reversed-phase high-performance liquid chromatography. Areas under the concentration-time curve from 0 h to infinity (AUC(0- infinity )) for elderly females and males were similar following administration of 1-g single i.v. doses, and thus, the genders were pooled in subsequent analyses. Concentrations in plasma and the half-life of ertapenem were generally higher and longer, respectively, in elderly subjects than in young adults. The mean AUC(0- infinity ) of total ertapenem in the elderly was 39% higher than that in young subjects following administration of a 1-g dose. The differences were slightly greater for the mean AUC(0- infinity ) of unbound ertapenem (71%). The unbound fraction of ertapenem in elderly subjects ( approximately 5 to 11%) was generally greater than that in young adults ( approximately 5 to 8%). As in young adults, ertapenem did not accumulate upon multiple dosing in the elderly. The pharmacokinetics of ertapenem in elderly subjects, while slightly different from those in young adults, do not require a dosage adjustment for elderly patients.

Clinical pharmacology studies in UK Phase 1 units: an AHPPI survey 1999-2000

AIMS

This study, conducted by the Association for Human Pharmacology in the Pharmaceutical Industry (AHPPI), was designed to determine the amount of Phase 1 activity in the UK in the period 1999-2000, the timelines involved for submissions to ethics committee and responses from ethics committees.

METHODS

A questionnaire was completed by AHIPPI members from pharmaceutical companies with in-house phase 1 units, by Clinical Research Organizations (CRO's) and by academic centres. A few responses were also vailable from organisations that were not AHPPI members. Results were rendered anonymous and grouped by category.

RESULTS

The response rate was > 98% and indicated that the vast majority of early drug research in humans is now CRO-based (82%). The total number of studies (as indicated by protocol numbers) was notably similar across the 2 years--629 in 1999 and 606 in 2000. Turnaround time for ethics committee review was a mean of 14 days.

CONCLUSIONS

These data set important benchmarks for early-phase drug research in the UK where regulatory approval is not currently required. Furthermore, the information should be used as a guide if the competitive nature of such work in the UK is to be maintained as new national legislation is implemented following publication of the European Union (EU) Clinical Trials Directive.

Influence of beta-adrenoceptor antagonists on the pharmacokinetics of rizatriptan, a 5-HT1B/1D agonist: differential effects of propranolol, nadolol and metoprolol

AIMS

Patients with migraine may receive the 5-HT1B/1D agonist, rizatriptan (5 or 10 mg), to control acute attacks. Patients with frequent attacks may also receive propranolol or other beta-adrenoceptor antagonists for migraine prophylaxis. The present studies investigated the potential for pharmacokinetic or pharmacodynamic interaction between beta-adrenoceptor blockers and rizatriptan.

METHODS

Four double-blind, placebo-controlled, randomized crossover investigations were performed in a total of 51 healthy subjects. A single 10 mg dose of rizatriptan was administered after 7 days' administration of propranolol (60 and 120 mg twice daily), nadolol (80 mg twice daily), metoprolol (100 mg twice daily) or placebo. Rizatriptan pharmacokinetics were assessed. In vitro incubations of rizatriptan and sumatriptan with various beta-adrenoceptor blockers were performed in human S9 fraction. Production of the indole-acetic acid-MAO-A metabolite of each triptan was measured.

RESULTS

Administration of rizatriptan during propranolol treatment (120 mg twice daily for 7.5 days) increased the AUC(0, infinity) for rizatriptan by approximately 67% and the Cmax by approximately 75%. A reduction in the dose of propranolol (60 mg twice daily) and/or the incorporation of a delay (1 or 2 h) between propranolol and rizatriptan administration did not produce a statistically significant change in the effect of propranolol on rizatriptan pharmacokinetics. Administration of rizatriptan together with nadolol (80 mg twice daily) or metoprolol (100 mg twice daily) for 7 days did not significantly alter the pharmacokinetics of rizatriptan. No untoward adverse experiences attributable to the pharmacokinetic interaction between propranolol and rizatriptan were observed, and no subjects developed serious clinical, laboratory, or other significant adverse experiences during coadministration of rizatriptan with any of the beta-adrenoceptor blockers. In vitro incubations showed that propranolol, but not other beta-adrenoceptor blockers significantly inhibited the production of the indole-acetic acid metabolite of rizatriptan and sumatriptan.

CONCLUSIONS

These results suggest that propranolol increases plasma concentrations of rizatriptan by inhibiting monoamine oxidase-A. When prescribing rizatriptan to migraine patients receiving propranolol for prophylaxis, the 5 mg dose of rizatriptan is recommended. Administration with other beta-adrenoceptor blockers does not require consideration of a dose adjustment.

Pharmacokinetics and food interaction of MK-462 in healthy males

A study was conducted to assess the safety, tolerability, and pharmacokinetics of single intravenous (IV) doses of 5-90 micrograms kg-1 of MK-462, and the effect of food on the pharmacokinetics of MK-462 administered orally to healthy males. Results of this study indicate that IV doses of MK-462 from 5 to 90 micrograms kg-1 are well tolerated. The disposition kinetics of MK-462 were linear for IV doses up to and including 60 micrograms kg-1. The values of the plasma clearance (CL), steady-state volume of distribution (Vss), plasma terminal half-life (t1/2), and mean residence time in the body (MRT) of MK-462 averaged 1376 mL min-1, 140 L, 1.8 h, and 1.7 h, respectively, and remained essentially constant over the dosage range of 10-60 micrograms kg-1 of IV MK-462. However, as the dose increased from 60 to 90 micrograms kg-1, the mean value of the apparent CL decreased from 1376 to 807 mL min-1. Thus, elimination of MK-462 was dose dependent in this dosage range. Based on the disposition decomposition analysis (DDA), it was shown that the Vss value of MK-462 remained essentially constant over the dosage range of 10-90 micrograms kg-1 of IV MK-462. The following values of two dose-independent parameters were also calculated by using DDA: distribution clearance (CLd) = 2028 mL min-1, and mean transit time in the peripheral tissues (MTTT) = 0.74 h. The mean values of AUC, Cmax, tmax, and apparent t1/2 of MK-462 in 12 subjects each receiving a 40 mg tablet of MK-462 without breakfast were 330 ng.h mL-1, 77 ng mL-1, 1.6 h, and 1.8 h, respectively. Although administration of a standard breakfast prior to dosing increased the AUC value (by approximately 20%) of MK-462 and delayed its absorption, there were no significant effects of the meal on the values of Cmax and apparent t1/2 of MK-462.

Assessment of MK-467, a peripheral alpha 2-adrenergic receptor antagonist, with intravenous clonidine

The activity of MK-467, a new peripherally acting alpha 2-antagonist, was assessed in volunteers by a randomized, double-blind, crossover design. One hour after administration of either 15 mg or 30 mg MK-467 or placebo, 200 micrograms clonidine was given intravenously and observations were made for a further 8 hours. Clonidine reduced plasma norepinephrine levels to 79% +/- 7% of that of control 1 hour after infusion, an effect that was antagonized by low-dose MK-467 (p less than 0.05). Mean systolic blood pressure increased by 4 mm Hg in the first hour after the 30 mg dose of MK-467 (p less than 0.01), although there was no significant difference between the 3 study days in the maximal clonidine-induced decrease in systolic pressure, diastolic pressure, or heart rate. Clonidine induced a peak increase in mean blood glucose of 13%, which was antagonized by both doses of MK-467 (p less than 0.05). Plasma insulin was suppressed by clonidine from 72 +/- 14 to 47 +/- 7 IU.L-1, an effect antagonised by both doses of MK-467 (p less than 0.05 in each case). MK-467 had no effect on clonidine-induced increased drowsiness, xerostomia, or increase in growth hormone secretion, which is consistent with it being a peripherally acting specific alpha 2-antagonist. The small effect of MK-467 on clonidine-induced changes in plasma glucose and insulin suggests that peripheral alpha 2-adrenergic receptors play only a minor role in normal glucose homeostasis.