No abstract

A phase I dose-escalating clinical trial of andrographolide from Andrographis paniculata was conducted in 13 HIV positive patients and five HIV uninfected, healthy volunteers. The objectives were primarily to assess safety and tolerability and secondarily to assess effects on plasma virion HIV-1 RNA levels and CD4(+) lymphocyte levels. No subjects used antiretroviral medications during the trial. Those with liver or renal abnormalities were excluded. The planned regimen was 5 mg/kg bodyweight for 3 weeks, escalating to 10 mg/kg bodyweight for 3 weeks, and to 20 mg/kg bodyweight for a final 3 weeks. The trial was interrupted at 6 weeks due to adverse events including an anaphylactic reaction in one patient. All adverse events had resolved by the end of observation. A significant rise in the mean CD4(+) lymphocyte level of HIV subjects occurred after administration of 10 mg/kg andrographolide (from a baseline of 405 cells/mm(3) to 501 cells/mm(3); p = 0.002). There were no statistically significant changes in mean plasma HIV-1 RNA levels throughout the trial. Andrographolide may inhibit HIV-induced cell cycle dysregulation, leading to a rise in CD4(+) lymphocyte levels in HIV-1 infected individuals.

The pharmacokinetics of intravenously and orally administered enrofloxacin was determined in fingerling rainbow trout (Oncorhynchus mykiss). Doses of 5 or 10 mg enrofloxacin/kg body weight were administered intravenously to 26 fish for each dose and blood was sampled over a 60-h period at 15 degrees C. Two groups of fish were treated orally with 5, 10, or 50 mg/kg (80 fish/dose at each temperature) and held at 15 degrees C or 10 degrees C during the 60-h sampling period. Following intravenous administration, the serum concentration-time data of enrofloxacin in rainbow trout were best described by a two-compartment open model for both doses of 5 and 10 mg enrofloxacin/kg. The hybrid rate constants alpha and beta did not differ between doses. The distributional phase was rapid with a half-life of 6-7 min for both doses. Overall half-lives of elimination were 24.4 h (95% CI = 20.2-30.8) and 30.4 h (24.2-41.0), respectively, for the 5- and 10-mg/kg doses. A large Vd(area) was observed following dosing of either 5 or 10 mg enrofloxacin/kg,: 3.22 and 2.56 l/kg, respectively. Whole body clearance for 5 mg/kg was 92 ml/h.kg and 58 ml/h.kg at the 10-mg/kg dose. Following oral administration, the serum concentration-time data for enrofloxacin were best described as a one-compartment open model with first-order absorption and elimination. Apparent Ka over all doses at 10 degrees C averaged 62% less than apparent Ka at 15 degrees C. Estimates of the apparent t(1/2)e over both temperatures ranged from 29.5 h (18.4-73.4) to 56.3 h (38.3-106.6). Bioavailability averaged 42% over all doses at 15 degrees C and was decreased to an average of 25% at 10 degrees C. Peak serum concentrations appeared between 6 and 8 h following dosing. A dose of 5 mg/kg/day was estimated to provide average steady-state serum concentrations at 10 degrees C that are approximately 4.5 times the highest reported MIC values for Streptococcus spp., the fish pathogen least sensitive to enrofloxacin. Owing to the long apparent half-life of elimination of enrofloxacin in fingerling trout, it would take approximately 5 to 9 days to achieve these predicted steady-state serum concentrations; this estimate is important when considering the duration of therapy in clinical trials.

No abstract

The fluoroquinolone antibacterial family is a relatively recent group of bactericidal compounds, generally characterized by efficacy against a wide spectrum of bacterial organisms and exhibiting minimal adverse effects in treated patients. The fluoroquinolones are widely prescribed in both human and veterinary medicine, though in veterinary medicine in the USA there are currently only two approved compounds, enrofloxacin (Baytril, Bayer Animal Health, Shawnee Mission, KS) and sarafloxacin (SaraFlox, Abbott Laboratories, North Chicago, IL), both with limited species and disease label approvals. Currently, there are no approved fluoroquinolone antibacterials to treat bacterial infectious diseases in cultured fish species. Enrofloxacin was administered to juvenile Atlantic salmon as a single bolus via intraarterial (i.a.), intraperitoneal (i.p.), intramuscular (i.m.), or oral gavage routes of administration. The drug was administered via the first three routes to achieve a dose of 10 mg/kg, and via oral gavage to achieve both 10 (p.o.-10) and 5 (p.o.-5) mg/kg doses. Two-compartment model kinetics were observed with elimination of half-lives (t1/2) of 130.6, 34.32, 84.98, 105.11, and 48.24 h, area under the drug concentration-time curves (AUC) of 84.3, 75.31, 55.61, 41.68, and 38.81 micrograms x h/mL, and bioavailabilities (F) of 100, 89.34, 65.97, 49.44, and 46.04% (i.a., i.p., i.m., p.o.-10, p.o.-5, respectively). All administration routes at 10 mg/kg were found to yield comparable drug concentration-time curves for multiple tissue, indicating no distinct advantage of using one route over another from a kinetics perspective. Finally, the 5 mg/kg dose (p.o.-5) yielded comparable multiple tissue drug concentration-time curves to the 10 mg/kg dose (p.o.-10), providing pharmacokinetic evidence to justify therapeutic efficacy trials with the lower dose.

No abstract

No abstract

Streptococcal infection (Streptococcus iniae) was diagnosed sequentially in two tanks of hybrid striped bass Morone saxatilis male ×M. chrysops female (Sunshine bass) grown in a commercial freshwater recirculation facility in western Massachusetts. The pathogen was isolated in the laboratory, biochemically and morphologically characterized, and antibacterial sensitivities determined. Streptococcus iniae‐induced lesions in the Sunshine bass were character at the gross and histopathological levels. Initial treatment with oxytetracycline was unsuccessful. Based on sensitivity results, enrofloxacin‐medicated feed was dosed at 10 mg/kg body weight for 10 d, while a subsequent trial was conducted at 5 mg/kg body weight for 10 d. Mortality of fish subsided promptly following initiation of enrofloxacin therapy, yielding a final mortality in the initial tank of 10.83% (control tank 55.5%) and in the second tank of 16.97% (control tank 39.8%). Tissue enrofloxacin residues, detected via a microbiologic bioassay, revealed greater quantities and longer duration of residues in various tissues from the 5‐mg as compared to the 10‐mg trial, potentially the result of adverse feed palatability. Enrofloxacin appears to have excellent potential as an antibacterial agent for treating susceptible bacterial diseases of Sunshine bass.