Safety, tolerability and pharmacokinetics of intravaginal pentamycin.

BACKGROUND/AIMS: Intravaginal pentamycin is a polyene macrolide with a broad spectrum of antimicrobial activity and is effective in various forms of infectious vaginitis. We evaluated the safety, tolerability and pharmacokinetics of escalating doses of this product. METHODS: Nineteen healthy volunteers were randomized to receive double blind one of five doses of intravaginal pentamycin (3, 10, 30, 60 or 100 mg) or the corresponding dose of pentamycin vehicle daily for 6 days. Patients with symptomatic vaginitis received a single dose of 60 (n = 6) or 100 mg (n = 6) of intravaginal pentamycin. Safety and tolerability parameters were monitored throughout the study. Plasma concentrations of pentamycin were measured daily in the healthy volunteers and on the day of drug application in the patients. RESULTS: The most frequently reported adverse events were mild or moderate vaginal discharge and mild symptoms of vaginal irritation (mainly pruritus or burning sensation), which also occurred in women who applied the vehicle. No patient with symptomatic vaginitis reported treatment-related adverse events. The plasma levels of pentamycin were below the quantification limit in all samples. CONCLUSION: Intravaginal pentamycin does not cause adverse reactions compared with vehicle and is not absorbed through the intact or the inflamed vagina.

Clopidogrel loading dose regimens: kinetic profile of pharmacodynamic response in healthy subjects.

Clopidogrel, a potent novel platelet ADP-receptor antagonist, induces a significant inhibition of ADP-induced platelet aggregation. Maximum inhibition of 40 to 50% is observed 2 to 5 hours after a single 400 mg dose. The same level of inhibition is achieved with 75 mg once daily at steady state, i.e., after 3 to 7 days of repeated dosing. Based on these data, two studies were undertaken to investigate whether a treatment regimen comprising a large initial dose (loading dose) of clopidogrel, followed by daily doses of 75 mg, might provide a sustained steady-state level of inhibition of platelet aggregation induced by 5 microM of ADP within hours after first dosing. In one study, 10 healthy male subjects received a 375 mg loading dose of clopidogrel on day 1, then daily doses of 75 mg from day 2 to day 10. Mean inhibition of platelet aggregation, already significant at 30 minutes, reached 55+/-8.2% (+/-SEM) at 60 minutes, and a maximum of 80+/-3.6% at 5 hours. No further significant change was observed between 5 hours and 24 hours, and from day 2 through day 10 with subsequent daily doses of 75 mg. In the second study, conducted according to a randomized, single-blind design, four parallel treatment groups of nine healthy male subjects received a loading dose of 75 mg, 150 mg, 225 mg, or 300 mg of clopidogrel on day 1, respectively, and 75 mg once daily from day 2 to day 5. Mean (+/-SD) inhibition of platelet aggregation over the 2 to 24 hours post-loading dose period was 22+/-14.5%, 21+/-13.4%, 35+/-20.6% and 31+/-13.3%, respectively. On day 5, it was 48+/-14.7%, 33 +/-14.1%, 51+/-15.7% and 40+/-10.9% for the 75, 150, 225 and 300 mg loading dose groups, respectively. The smallest day 1 to day 5 difference was observed for the 300 mg group and the largest for the 75 mg group, indicating that the development of the full inhibitory effect of clopidogrel was faster with the loading doses higher than with 75 mg, and fastest with the 300 mg loading dose. These data and those of previous studies indicate that a dose of 300 to 400 mg produces a rapid onset of the pharmacodynamic action of clopidogrel, with levels of inhibition close to steady-state reached within 2 hours.

Immunogenicity of a recombinant Pre-S2-containing hepatitis B vaccine versus plasma-derived vaccine administered as a booster.

GenHevac B Pasteur is a recombinant hepatitis B vaccine derived from a mammalian cell line and containing HBs as well as pre-S2 antigens. Its immunogenicity was compared to that of the plasma-derived vaccine Hevac B Pasteur in a population primovaccinated 5.5 years earlier with four injections of the same plasma vaccine. The booster injection with either GenHevac or Hevac was administered to 295 subjects with residual anti-HBs titres below 500 IU/l (group 1: 0-9; group 2: 10-99; group 3: 100-499 IU/l). After four weeks, GenHevac had induced higher anti-HBs responses than Hevac in all groups, particularly among the low responders of group 1. Response to the vaccine occurred earlier with GenHevac. Mean anti-pre-S2 production was moderate in all groups for both vaccines (GenHevac: 60 IU/l; Hevac: 31 IU/l) and was not found in the 32 subjects who produced less than 100 IU/l anti-HBs. The results of the present study indicate that GenHevac is at least as immunogenic as Hevac.

Anti-pre-S2 antibody response in subjects vaccinated against hepatitis B and in naturally immunized subjects.

Serum samples from individuals immunized with a pepsinized or non-pepsinized vaccine and from patients who had recovered from acute hepatitis B or who developed a chronic form of the disease, were analysed for the presence of antibody against the pre-S2 epitope of the hepatitis B virus. Anti-pre-S2 antibody was absent in all but one individual immunized with the pepsinized vaccine. Thirty-eight percent of the subjects who responded by anti-HBs production to the non-pepsinized preparation showed anti-pre-S2 antibody one year after complete vaccination. Among subjects who did not produce anti-HBs after immunization with this vaccine, 1 single individual produced anti-pre-S2 antibody. Anti-preS2 antibody was detectable after one year in 38% of the patients who recovered from acute hepatitis B, but in none of those with chronic hepatitis B. The kinetics of anti-pre-S2 antibody response to a booster injection was also analysed 1 month and 1 year after the 3rd injection and 1 month after the 4th injection of the non-pepsinized vaccine.

Monotherapy with valproate in primary generalized epilepsies.

Sodium valproate enteric-coated tablets were administered as monotherapy to 118 patients (median age, 19 years) with primary generalized epilepsies. More than half (56%) of these patients were transferred from prior drug therapy, most of them because of inadequate seizure control, and some because of adverse effects. Seventy-one percent of the patients experienced tonic-clonic seizures, either alone or in combination with other types of seizures, principally absences. Mean duration of follow-up was 18 months (median, 17 months; range, 1-68 months). At a mean daily dosage of less than 20 mg/kg, 83% of the patients became seizure-free. Therapy was equally effective against tonic-clonic seizures, absences, and myoclonic seizures. Tonic-clonic seizures were suppressed in 85% of cases (89% when patient had only one seizure type), absences in 82% (95% when patient had only one seizure type), and myoclonic seizures in 82%. Paroxysmal activity was present in 88% of the electroencephalogram (EEG) records before valproate monotherapy, and in 32.4% at the study's end. These results were achieved with generally mild and mostly transient side effects; side effects were reported by 16% of patients during the first month, and 2% at the last follow-up. No hematologic or hepatic toxicity was observed. The lag time between attaining steady-state serum concentrations and achieving maximal clinical improvement suggests that sodium valproate monotherapy should be given an adequate trial to ensure that patients derive the greatest possible benefit before adding or switching to another drug.