An evaluation of the effects of rinbacin on the liver and blood of albino rats was carried out. Low (26.25 g/l) and high (52.50 g/l) dose levels of rinbacin were administered in the drinking water of albino rats for 13 weeks. Food and fluid intake were measured daily, and animal body weight taken weekly. Biochemical analysis of the liver function was carried out as well as some haematological parameters and histology of the liver. Results showed a significant (p ≤ 0.05) increase in all the liver function parameters tested at both dose levels. There was also an increase in packed cell volume (PCV) in the high dose group. Histological examination indicates that rinbacin at both dose sizes induced severe pathologic changes in the forms of degeneration of hepatocytes, necrosis, oedema, cellular infiltration, nuclear fragmentation and chromatinolysis. Administration of rinbacin, though could raise the PCV, may lead to hepatic damage, which might result in increased bilirubin and liver enzymes in rats. Rinbacin is toxic to the rat liver.

Ciprofloxacin is an inexpensive antibacterial, whereas chloroquine is an inexpensive antimalarial. The coadministration of chloroquine and ciprofloxacin is easily encountered because both drugs are commonly prescribed to patients in the tropics. Five healthy male volunteers aged 19 to 31 years who were not taking any of the prescribed medications and who had no sensitivity to either ciprofloxacin or chloroquine each received 500 mg ciprofloxacin orally with 250 mL of water, and after a 2-week washout period, 500 mg ciprofloxacin plus 600 mg chloroquine was administered orally with 250 mL of water after providing informed consent. A urine sample (7 mL) was collected just before taking the drug at 8:00 AM representing 0 hour and continued afterward at 1, 2, 4, 8, 12, and 24 hours the next day. The samples were stored at -20 degrees C until analyzed. The minimum inhibitory concentrations by diffusion through agar technique were used for the assay of urine ciprofloxacin. The rate of ciprofloxacin excretion and cumulative urine ciprofloxacin were significantly increased. The coadministration of chloroquine increased the cumulative urinary concentration and excretion rate of ciprofloxacin.

The effects of ciprofloxacin (CP), a fluoroquinolone antibacterial agent, on the extent of absorption of isoniazid (INH) and on some of its pharmacokinetic parameters were investigated in six healthy female volunteers between the ages of 23 and 32 years. The presence of CP led to increase in the amount of INH and to a slight reduction in its peak plasma concentration (Cmax). There was a 1-hour increase in the time to attain Cmax (tmax) of INH, indicating absorption interaction between the two drugs. This absorption interaction was related to inhibition of cholinergic neurotransmission caused by CP, which is capable of inhibiting gastric motility, leading to a delay in gastric emptying. The rate of elimination (K) and plasma half-life (t1/2) of INH were not significantly affected (P = 0.05). The extent of absorption interaction that may have occurred (based on values of 24-hour values for area under the concentration curve, Cmax, Tmax, K, and t1/2) was considered to be of no therapeutic consequence, and the coadministration of the two drugs may be recommended in clinical practice.

No abstract

The effect of pefloxacin on the pharmacokinetics parameters of rifampicin in humans was investigated using plasma and saliva concentrations. Five healthy volunteers (4 male and 1 female), ages 20-35 years, each received 600 mg rifampicin alone, and after a 1-week drug washout period, 600 mg rifampicin plus 500 mg pefloxacin was administered with 350 mL of water. Plasma and saliva concentrations of rifampicin were measured at 7 different time intervals and different pharmacokinetics parameters calculated. Pefloxacin coadministered with rifampicin reduced plasma and saliva elimination half-life, peak plasma concentration, area under the concentration time curve, volume of distribution, minimum absorption time, absorption rate constant, and absorption half-life showed a significant increase (P < 0.05). Time to reach peak plasma concentration was not affected with or without pefloxacin. Pefloxacin increases bioavailability of rifampicin and hence extends its detection in the body as demonstrated by rifampicin being estimated at 24 hours when coadministered with pefloxacin, whereas at 24 hours, it was completely absent when administered alone.