Influenza and meningococcal vaccinations are effective in healthy subjects treated with the interleukin-1 beta-blocking antibody canakinumab: results of an open-label, parallel group, randomized, single-center study.

The objective of this study was to evaluate the efficacy of influenza and meningococcal vaccines in healthy subjects exposed to the anti-interleukin-1ß (anti-IL-1ß) monoclonal antibody canakinumab. This was an open-label, parallel group, randomized, single-center study of healthy subjects (aged 18 to 45 years). At baseline, antibody (Ab) titers were measured and subjects were randomized (1:1) to a single 300-mg canakinumab dose administered subcutaneously (s.c.) or received no treatment (control group). After 2 weeks, subjects were treated with inactivated, unadjuvanted influenza and conjugated group C meningococcal (MenC) vaccines, administered intramuscularly (i.m.). The primary efficacy variable was the response (≥ 2-fold increase in Ab titer in ≥ 2 of 3 influenza virus strains) after 4 weeks in subjects treated with canakinumab compared to the control group. Secondary efficacy variables were the antibody response to vaccines at different thresholds and time points. Fifty-one of 112 subjects screened were randomized to canakinumab (n = 25) or the control group (n = 26). Antibody responses to vaccinations measured against different influenza virus strains and one MenC strain at 4 weeks were comparable in the canakinumab and control groups. The primary efficacy variable, the response to influenza vaccination (≥ 2-fold increase in Ab titer in ≥ 2 of 3 serotypes) at 4 weeks, was shown in 24/25 subjects in the canakinumab group compared to 25/25 subjects in the control group. Antibody responses remained comparable in the two groups at the different time points assessed. Headache was the most frequently reported adverse event. No deaths or serious adverse events were reported during the study. We concluded that a single dose of 300 mg canakinumab s.c. does not affect the induction or persistence of antibody responses after vaccination with unadjuvanted influenza or alum-adjuvanted MenC vaccines in healthy subjects.

Bioequivalence study comparing a new paracetamol solution for injection and propacetamol after single intravenous infusion in healthy subjects.

OBJECTIVES: A new, ready-to-use solution for injection of paracetamol (Perfalgan 10 mg/ml) without previous reconstitution has been developed. The aim of the study was to determine the serum concentration profiles of paracetamol after 15 min infusion of Perfalgan 0.5 g and 1 g doses and to demonstrate the bioequivalence between Perfalgan 1 g dose and a marketed reference formulation for injection, propacetamol 2 g (Pro-Dafalgan 2 g) equivalent to 1 g of paracetamol. The secondary objective was to evaluate local tolerance, and clinical and biological safety. METHODS: The study was performed in 24 healthy, male volunteers, according to an open-label, randomized, single-dose, 3-period crossover design, with a 1-week washout period between the doses. Blood samples were taken prior to each administration and at 18 time points within the 24-hour period following the beginning of each infusion. Serum concentrations of paracetamol were determined by validated high-performance liquid chromatography with UV detection. From serum concentration-time data, a non-compartmental pharmacokinetic analysis was performed to calculate Cmax, tmax, AUC(inf), t(1/2), MRT, Cl(T) and Vd. Log-transformed AUC(inf) and Cmax were tested for bioequivalence. The local pain intensity at infusion site was assessed using a 4-point categorical scale from 0 (none) to 3 (severe). The clinical and biological safety was evaluated by physical examination with measurements of vital signs and ECG and laboratory tests including hematology and biochemistry. RESULTS: After infusion of 0.5 g and I g of the new paracetamol solution, C(max) and AUC(inf) increased proportionally with dosage. After dose correction to 1 g of paracetamol, the mean (+/- SD) Cmax ratio was 0.98 +/- 0.24 and 0.94 +/- 0.08 for AUC ratio. Identical t(max) was observed for the 2 paracetamol dosages and 90% confidence intervals for t(1/2), MRT, Cl(T) and V(d) were within the acceptable interval 0.8-1.25. The calculated 90% confidence intervals of the new solution (Perfalgan 1 g) to marketed solution (propacetamol 2 g) ratios were 1.11-1.31 (point estimate 1.20) for C(max) and 1.10-1.16 (point estimate 1.13) for AUC(inf). These values were within the acceptable bioequivalence intervals of 0.75 to 1.33 for Cmax and 0.80-1.25 for AUC(inf). Application site disorders were the most frequently observed adverse events but local pain at infusion site was less reported by subjects after Perfalgan (2%) compared to propacetamol (20%). The clinical and biological safety was good and equivalent for the 3 treatments. CONCLUSION: After administration of paracetamol solution for injection 0.5 g and 1 g, the pharmacokinetics of paracetamol is linear. All results indicate that 1 g of paracetamol administered as Perfalgan 10 mg/ml is bioequivalent to propacetamol 2 g with a better local safety.

Interruptions to the physician-patient encounter: an intervention program.

BACKGROUND: Israeli physicians are very familiar with the problem of interruptions during encounters with patients. However, a thorough search of the medical literature revealed only one report of this problem from Israel, and none from other countries. OBJECTIVES: To characterize the phenomenon of interruptions to the patient-physician encounter in a clinic in Dimona and to assess the effect of an intervention program designed to reduce the magnitude of this problem. METHODS: During an 8 day work period in March 1997 all patient-physician encounters were recorded and characterized. An intervention program was then designed and implemented to reduce the number of interruptions. Data were again collected a year after the initial data collection. RESULTS: During the 8 day study period prior to the intervention program there were 528 interruptions to 379 encounters (mean of 1.39 per encounter). The main causes of interruptions were entrance of uninvited patients to the examination room (31%) and telephone calls (27%). Most of the interruptions occurred during the morning hours between 8 and 10 a.m. (45%) and at the beginning of the week (Sunday 30%). After the intervention program there were 402 interruptions to 355 encounters (mean of 1.13 per appointment, P = 0.21). CONCLUSIONS: There was no statistically significant improvement in the number of interruptions following the intervention program. This finding is either the result of a local cultural phenomenon, or it indicates a national primary care health system problem that may require a long-term educational program to resolve it. Further research is needed on the magnitude, causes and consequences of interruptions in family practice and, if warranted, methods will have to devised to cope with this serious problem.

Muscular blood flow response to submaximal leg exercise in normal subjects and in patients with heart failure.

Blood flow to working skeletal muscle is usually reduced during exercise in patients with congestive heart failure. An intrinsic impairment of skeletal muscle vasodilatory capacity has been suspected as a mechanism of this muscle underperfusion during maximal exercise, but its role during submaximal exercise remains unclear. Therefore, we studied by transcutaneous Doppler ultrasonography the arterial blood flow in the common femoral artery at rest and during a submaximal bicycle exercise in 12 normal subjects and in 30 patients with heart failure. Leg blood flow was lower in patients than in control subjects at rest [0.29 +/- 0.14 (SD) vs. 0.45 +/- 0.14 l/min, P < 0.01], at absolute powers and at the same relative power (2.17 +/- 1.06 vs. 4.39 +/- 1.4 l/min, P < 0.001). Because mean arterial pressure was maintained, leg vascular resistance was higher in patients than in control subjects at rest (407 +/- 187 vs. 247 +/- 71 mmHg.l-1.min, P < 0.01) and at the same relative power (73 +/- 49 vs. 31 +/- 13 mmHg.l-1.min, P < 0.01) but not at absolute powers. Although the magnitude of increase in leg blood flow corrected for power was similar in both groups (31 +/- 10 vs. 34 +/- 10 ml.min-1.W-1), the magnitude of decrease of leg vascular resistance corrected for power was higher in patients than in control subjects (5.9 +/- 3.3 vs. 1.9 +/- 0.94 mmHg.l-1.min.W-1, P < 0.001). These results suggest that the ability of skeletal muscle vascular resistance to decrease is not impaired and that intrinsic vascular abnormalities do not limit vasodilator response to submaximal exercise in patients with heart failure.

Pressor effect of oral tyramine during treatment with befloxatone, a new reversible monoamine oxidase-A inhibitor, in healthy subjects.

The interaction between tyramine and befloxatone, a new selective, reversible monoamine oxidase-A (MAO-A) inhibitor, was studied in a single-blind, parallel-group study in 30 healthy male volunteers whose fasting tyramine 30 dose (Tyr30) was 400 or 600 mg. Each subject completed a placebo run-in period followed by a befloxatone period. Befloxatone was given in repeated doses according to one of three regimens: befloxatone 20 mg once daily at the end of a meal rich in tyramine or befloxatone 10 or 20 mg twice daily 2 hours before a meal rich in tyramine. Subjects were given increasing daily doses of tyramine mixed with the meal, until a systolic blood pressure increase of at least 30 mm Hg was achieved (Tyr30). The mean Tyr30 decreased from 1220 mg (range, 600-1800 mg) during placebo to 290 mg (range, 150-500 mg) during befloxatone 20 mg once daily, 250 mg (range, 100-300) during befloxatone 10 mg twice daily, and 155 mg (range, 100-250 mg) during befloxatone 20 mg twice daily; corresponding to a potentiation factor of 5.2-, 6.5-, and 7.9-fold, respectively. The extent and the duration of the systolic blood pressure increase did not significantly differ between the placebo and the befloxatone regimens, except for a longer duration with the 20-mg twice daily regimen. These results are similar to those reported with the therapeutic dosage of other selective MAO-A inhibitors. They suggest that there would be little risk of hypertensive crisis in patients treated in clinical studies with befloxatone, and thus dietary restrictions appear to be unnecessary when the drug is given in a regimen of up to 20-mg once daily after meals.