Correlates of HIV, HBV, and HCV infections in a prison inmate population: results from a multicentre study in Italy.

A cross-sectional study was undertaken on the correlates of infection for the human immunodeficiency virus (HIV) and hepatitis viruses B and C (HBV and HCV) in a sample of inmates from eight Italian prisons. A total of 973 inmates were enrolled [87.0% males, median age of 36 years, 30.4% intravenous drug users (IDUs), 0.6% men who have sex with men (MSWM)]. In this sample, high seroprevalence rates were found (HIV: 7.5%; HCV: 38.0%; anti-HBc: 52.7%; HBsAg: 6.7%). HIV and HCV seropositivity were associated strongly with intravenous drug use (OR: 5.9 for HIV; 10.5 for HCV); after excluding IDUs and male homosexuals, the HIV prevalence remained nonetheless relatively high (2.6%). HIV prevalence was higher for persons from Northern Italy and Sardinia. The age effect was U-shaped for HIV and HCV infections; HBV prevalence increased with age. Tattoos were associated with HCV positivity (OR: 2.9). The number of imprisonments was associated with HIV infection, whereas the duration of imprisonment was only associated with anti-HBc. The probability of being HIV-seropositive was higher for HCV-seropositive individuals, especially if IDUs. In conclusion, a high prevalence of HIV, HCV, and HBV infections among inmates was observed: these high rates are in part attributable to the high proportion of IDUs. Frequency of imprisonment and tattoos were associated, respectively, with HIV and HCV positivity. Although it is possible that the study population is not representative of Italy's prison inmate population, the results stress the need to improve infection control measures users was prisons.

Effect of food on nifedipine pharmacokinetics.

The effect of food on the bioavailability of nifedipine (Procardia), 10 mg capsules, was studied. Each of 15 male volunteers received a single oral 10 mg dose with 120 ml water under three conditions: fasting, after a low-fat (high-carbohydrate) meal, and after a high-fat meal. An open, three-way Latin-square design was employed with a 4-day washout period between administrations. Serial blood samples were collected just before the dose (0 hour) and from 0 to 8 hours after administration. Nifedipine assays were performed by GLC/electron capture detection. Diet did not appreciably alter the AUC from 0 to 8 hours, the AUC from 0 to infinity, or the elimination half-life. The time to peak (tmax) and peak concentrations (Cmax) were significantly altered by food. The mean Cmax values for fasting, low-fat, and high-fat meals were 78.9, 42.2, and 58.7 ng/ml, respectively. The mean tmax values for these three conditions were 0.97, 1.89, and 1.07 hours, respectively. The results indicate that food, in particular a low-fat (high-carbohydrate) meal, slows the rate but does not alter the extent of nifedipine absorption. Insofar as certain side effects (e.g., flushing and headache) may be related to the high peak plasma levels associated with rapid absorption, administration with meals might serve to reduce the incidence of such effects. Clinical trials would be necessary to confirm this possibility. For the majority of patients on routine maintenance therapeutic regimens, nifedipine capsules may be administered without regard to food intake.

High-performance liquid chromatographic determination of cefoperazone in human serum and urine.

A gradient high-performance liquid chromatographic (HPLC) procedure has been developed for the determination of microgram amounts of cefoperazone in human serum and urine. The method employs a muBondapak C18 column and gradient elution with two mobile phases. Excellent separation of the drug from potential degradation products as well as from representative penicillins (sodium ampicillin, sodium methicillin, potassium penicillin G) and aminoglycosides (tobramycin, gentamicin, kanamycin) has been demonstrated. Coefficients of variation of 7.3% or less were obtained for 25-100 micrograms/ml cefoperazone in both serum and urine. Average recoveries of the drug from spiked serum and urine samples corresponded to 97.6% and 98.6%, respectively. Amounts as low as 1 microgram cefoperazone per ml of sample can be estimated using sample volumes corresponding to 0.1 ml serum or 1 ml urine. Good correlation between the HPLC assay and a microbiological cylinder-plate assay employing Micrococcus luteus ATCC 9341 has been demonstrated for human serum and urine of patients treated with cefoperazone. While the microbiological method is less time-consuming, it lacks specificity in the presence of other antibiotics. The HPLC method can be used to analyze cefoperazone in the presence of penicillins and aminoglycosides which can potentially be co-administered with cefoperazone.

Determination of polythiazide and prazosin in human plasma by high-performance liquid chromatography.

A selective high-performance liquid chromatographic method has been developed for the determination of polythiazide in human plasma down to concentrations of 0.5 ng/ml. Polythiazide and an internal standard (epithiazide) are simultaneously extracted from the sample, the extract is purified on a silica micro-column and analyzed on a muBondapak CN column. Chloroform-methanol (97:3) is the eluent, with spectrophotometric detection at 264 nm. The extraction methodology developed for the analysis of polythiazide in blood plasma allows the simultaneous quantitative determination of prazosin, which is frequently administered together with thiazide diuretics. The precision and accuracy of both the polythiazide and the prazosin assays are excellent and are not seriously affected by the simultaneous presence of both drugs in the plasma. Therefore, determination of polythiazide and prazosin is possible using a single plasma sample.