BACKGROUND: It appears likely that drugs other than NSAIDs may cause ulcers and ulcer complications (e.g. potassium chloride). Alendronate (Fosamax) is used in the treatment and prevention of metabolic bone disease and has also been associated with severe oesophageal damage and stricture. We have previously shown that the dose of alendronate used for Paget's disease (40 mg) causes gastric damage similar to NSAIDs. The usual dose for the treatment of postmenopausal osteoporosis is 10 mg per day. AIM: To investigate whether the 10 mg dose of alendronate causes gastric ulcers. METHODS: We performed an endoscopist-blind, crossover, randomized, single-centre comparison of 10 mg of alendronate/day and placebo in volunteers aged 40 years or more. Video-endoscopy was used to evaluate the presence and degree of mucosal damage to the oesophagus, stomach, or duodenal bulb after 7 and 14 days of treatment. RESULTS: Twenty-four healthy volunteers participated, including 15 women and nine men, ranging in age from 41 to 52 years. Visible gastric mucosal damage was present in nine (38%) who received alendronate compared to three (13%) in the placebo group. There was a marked difference in the severity of mucosal damage; there were no ulcers or large erosions in those receiving placebo. In contrast, potentially clinically significant gastric mucosal injury was seen in six subjects receiving alendronate (two developed antral ulcers and four had large (4-8 mm) superficial antral erosions) compared to none in the placebo group (P = 0.0219). One subject developed oesophageal damage in the form of multiple linear superficial erosions in the mid and distal oesophagus. Duodenal injury was not seen. CONCLUSION: Alendronate causes gastric ulceration, suggesting that alendronate use may be associated with ulcer complications such as acute upper gastrointestinal bleeding. The results of this study suggest the need for post-marketing surveillance to clarify the nature, frequency and magnitude of any potential gastrointestinal side-effects associated with the use of this drug. (+info)
The pharmacokinetics and safety profile of oral ganciclovir in combination with trimethoprim in HIV- and CMV-seropositive patients.
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AIMS: We investigated the pharmacokinetics and safety profile of oral ganciclovir coadministered with trimethoprim in HIV-and CMV-seropositive patients. METHODS: In an open-label, randomized, 3-way crossover study, 12 adult males received oral ganciclovir 1000 mg every 8h, oral trimethoprim 200 mg once daily, or both drugs concomitantly in a sequence of three 7-day treatment periods. Pharmacokinetic parameters were determined and adverse events recorded for each treatment. RESULTS: The presence of trimethoprim significantly decreased CLr (12.9%, P=0.0068) and increased t1/2 (18.1%, P=0.0378) of ganciclovir. However, these changes are unlikely to be clinically meaningful. There were no statistically significant changes in trimethoprim pharmacokinetic parameters in the presence of ganciclovir, with the exception of a 12.7% increase in Cmin. Ganciclovir was well tolerated when administered alone or in combination with trimethoprin. CONCLUSIONS: There was no clinically significant pharmacokinetic interaction between oral ganciclovir and trimethoprim when coadministered. (+info)
Pharmacokinetics of intravenous and oral L-arginine in normal volunteers.
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AIMS: Recent studies in patients with cardiovascular diseases suggest potential for the use of orally administered L-arginine, the precursor of nitric oxide, as a therapeutic agent. This crossover study was designed to examine the pharmacokinetics of single i.v. and oral doses of L-arginine in healthy volunteers (n = 10). METHODS: A preliminary control study (n = 12) was performed to assess the variation in plasma L-arginine concentrations when ingesting a normal diet. The observed variation was taken into account when interpreting the pharmacokinetic data obtained after exogenous administration. RESULTS: The mean baseline plasma concentration of L-arginine in the control study was 15.1+/-2.6 microg ml(-1). After intravenous administration (30 g over 30 min), the plasma concentration reached 1390+/-596 microg ml(-1). The disappearance of l-arginine appeared biphasic, with an initial rapid disappearance due to concentration-dependent renal clearance followed by a slower fall in plasma concentrations due to nonrenal elimination. The peak concentration after oral administration (10 g) was 50.0+/-13.4 microg ml(-1), occurring 1 h after administration. Renal elimination was not observed after oral administration of this dose. The absolute bioavailability of a single oral 10 g dose of L-arginine is approximately 20%. CONCLUSIONS: This study provides basic knowledge of L-arginine pharmacokinetics in healthy humans. Intravenous and oral administrations show at minimum a biphasic pattern. Further studies will assess whether a similar profile is observed when the drug is administered to patients. (+info)
Pharmacokinetics of glycosylated recombinant human granulocyte colony-stimulating factor (lenograstim) in healthy male volunteers.
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AIMS: The aim of this open, randomised, crossover, parallel-group study was to compare the pharmacokinetics and neutrophil responses of lenograstim when administered subcutaneously (s.c.) and intravenously (i.v.). METHODS: A total of 27 healthy male volunteers was recruited. Lenograstim doses (0.5, 2, 5, or 10 microg kg(-1)) were administered s.c. or i.v. once-daily for 5 days, and then, after a 10-day washout period, vice versa for a further 5 days. Lenograstim concentrations and absolute neutrophil counts (ANCs) were measured predosing and postdosing on days 1 and 5. RESULTS: Maximum serum concentrations of lenograstim were higher following i.v. dosing (mean 5.2-185.5 vs 0.7-30.0 ng ml(-1) after s.c. dosing on day 1) and attained sooner (median 0.5-0.8 vs 4.7-8.7 h on day 1). However, apparent elimination half-lives of lenograstim were longer following s.c. dosing (mean 2.3-3.3 vs 0.8-1.2 h after i.v. dosing on days 1 and 5). ANCs increased in a dose-dependent manner with both routes of lenograstim, but more prolonged rises and higher ANC peaks were attained following s.c. doses. ANCs peaked on day 6 following 5 microg kg(-1) s.c. doses (mean peak=26.3x10(9) cells l(-1)), but on day 2 after 5 microg kg(-1) i.v. doses (mean peak = 12.4 x 10(9) cells l(-1)). Irrespective of route, the most common adverse events were headaches and back/spine pain; at doses of up to 5 microg kg(-1) these were mild and generally well tolerated. CONCLUSIONS: While supporting the use of both s.c. and i.v. administered lenograstim to treat neutropenia, these results demonstrate that neutrophil responses are more sustained and prolonged with the s.c. route. (+info)
Effect of electrostatic charge in plastic spacers on the lung delivery of HFA-salbutamol in children.
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AIMS: The effect of the electrostatic charge in plastic spacers in vivo on drug delivery to the lung of hydrofluoroalkane (HFA) salbutamol spray was studied in children. METHODS: Five children, aged 7-12 years, were included in a 3-way crossover randomised single-blind trial. Salbutamol HFA spray was delivered on 3 different study days from plastic spacers with mouthpiece. Pre-treatment of the spacers differed between study days: (a) Non-electrostatic 350 ml Babyhaler (coated with benzalkonium chloride) (b) New 350 ml Babyhaler (rinsed in water), and (c) New 145 ml AeroChamber (rinsed in water). Plasma salbutamol was measured before and 5, 10, 15 and 20 min after inhalation of four single puffs of 100 microg salbutamol. Cmax and Cav (5-20min) were calculated as a reflection of lung dose. RESULTS: For Cmax: (A) Non-electrostatic Babyhaler 4.3 ng ml(-1) (B) New Babyhaler 1.9 ng ml(-1) (C) New AeroChamber 1.6 ng ml(-1): AvsB (95% CI for difference 0.5-4.5 ng ml(-1)), A vs C (95% CI for difference 0.7-4.8 ng ml(-1)). The geometric mean ratio for A:B was 2.4 fold, and for A:C was 2.9 fold. The values for Cav were similar with ratios for A:B of 2.4 fold, and A: C of 4.1 fold. The nonelectrostatic Babyhaler delivered a significantly (P<0.05) higher lung dose (for both Cmax and Cav) than either of the other two spacers. CONCLUSIONS: The electrostatic charge in plastic spacers reduces lung dose in children by more than two-fold. This is clinically significant and the use of potentially electrostatically charged spacers should be avoided. (+info)
Trachoma: can trichiasis be treated with a sticking-plaster? A randomized clinical trial in China.
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Trachoma is the most frequent cause of preventable blindness in the world. At the trichiasis/entropion stage, lid surgery is recommended, but many patients only use epilation, which does not prevent loss of vision. We developed a new treatment that should be more accessible than lid surgery and more effective than epilation: a sticking plaster that forces eyelashes back to their correct position. The first randomized controlled trial was conducted in Shanghai with 57 patients to compare the plaster method with epilation. After 3 months of follow-up, with no attrition, 67% of those treated by the new method presented a good clinical status, vs none of those treated by epilation (P < 0.001). The new treatment was well tolerated and lid function remained normal. Although our results show overwhelming benefit of this new, simple treatment for trachoma at the trichiasis stage, more research is needed at the primary health care level and in other settings to determine the potential use of the new method on a large scale and by nonspecialists. (+info)
Pharmacokinetics of gatifloxacin and interaction with an antacid containing aluminum and magnesium.
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The pharmacokinetics of gatifloxacin (400 mg orally) and the influence of the antacid aluminum magnesium hydroxide (20 ml of Maalox 70) on the bioavailability of gatifloxacin in 24 healthy volunteers were assessed. In an open, randomized, six-period crossover study, the volunteers received either gatifloxacin alone (treatments A and D); aluminum magnesium hydroxide concomitant with gatifloxacin (treatment C); or aluminum magnesium hydroxide 2 h before (treatment B), 2 h after (treatment E), or 4 h after gatifloxacin administration (treatment F). Gatifloxacin concentrations were measured by a validated bioassay and high-performance liquid chromatography. Pharmacokinetics of a single 400-mg dose of gatifloxacin alone were characterized as follows (mean +/- standard deviation): peak concentration (Cmax), 3.8 +/- 0. 5 (treatment A) and 3.4 +/- 0.9 (treatment D) microgram/ml; time to Cmax, 1.4 +/- 0.8 (treatment A) and 1.7 +/- 0.7 (treatment D) h; area under the curve from time zero to infinity (AUC0-infinity), 33. 5 +/- 5.9 (treatment A) and 31.4 +/- 3.4 (treatment D) microgram. h/ml; urine recovery, (83 +/- 6)% (treatment A) and (84 +/- 8)% (treatment D). Comparison of the results obtained by bioassay showed a good correlation. Aluminum magnesium hydroxide administration 2 h before (treatment B) or concomitant with (treatment C) gatifloxacin decreased the Cmax by 45% (2.1 +/- 1.2 microgram/ml) or even 68% (1.2 +/- 0.4 microgram/ml) highly significantly (P < 0.01). AUC0-infinity was significantly reduced from 33.5 +/- 5.9 to 19.4 +/- 6.9 microgram. h/ml (by 42%) or even to 11.9 +/- 3.3 microgram. h/ml (by 64%) (P < 0. 01). If aluminum magnesium hydroxide was given 2 h after gatifloxacin (treatment E), there was no significant reduction of concentration in serum but AUC0-infinity was significantly reduced from 31.4 +/- 3.4 to 25.9 +/- 5.3 microgram. h/ml (18%) (P < 0.01). Aluminum magnesium hydroxide given 4 h after gatifloxacin (treatment F) showed no influence on the gatifloxacin pharmacokinetics. Therefore, the optimal time between gatifloxacin application and the intake of an aluminum-containing antacid should be 4 h. (+info)
Lack of effect of zafirlukast on the pharmacokinetics of azithromycin, clarithromycin, and 14-hydroxyclarithromycin in healthy volunteers.
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This randomized, open-label, crossover study was conducted to investigate whether the coadministration of zafirlukast would affect the pharmacokinetics of azithromycin, clarithromycin, or 14-hydroxyclarithromycin (14-OHC). Twelve healthy subjects (six males and six females) received single 500-mg doses of azithromycin and clarithromycin with and without zafirlukast given to a steady-state concentration. Blood was collected prior to all macrolide doses and for 3 and 10 days after each clarithromycin and azithromycin dose, respectively. Serum was assayed for azithromycin, clarithromycin, and 14-OHC concentrations by validated high-performance liquid chromatography assay systems. Data analyses were done by noncompartmental and nonparametric methods. Analysis of the patients indicated that the addition of steady-state concentrations of zafirlukast did not significantly alter the pharmacokinetic parameters of or overall exposure (based on the area under the concentration-time curve) to azithromycin, clarithromycin, and 14-OHC. While zafirlukast is a known inhibitor of CYP3A4, it does not appear to exert a clinically or statistically significant pharmacokinetic effect on azithromycin, clarithromycin, or 14-OHC. (+info)