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Biomedical subjects

G R Bailie

Publications and source records attributed to G R Bailie.

At least 19 recordsLinked to original sources
PubMed1995

Severe accidental dapsone overdose.

Acute poisoning from excessive dapsone (4,4-diaminodiphenylsulfone) intake in uncommon in the United States; no cases were reported during 1992. However, with the increasing use of dapsone for diseases other than leprosy and dermatitis herpetiformis, such as acne vulgaris, psoriasis, and Pneumocystis carinii pneumonia infection in acquired immunodeficiency syndrome, clinicians should be aware of potential toxicities. This report describes a case of accidental dapsone intoxication resulting in severe cyanosis with a modest elevation in methemoglobin concentration.

Charcoal↗
PubMed1995

Absorption interactions with fluoroquinolones. 1995 update.

The utility of the fluoroquinolone class of antibiotics is rapidly expanding due to their favourable pharmacokinetic profile and the continuing development of new compounds. These agents are often used for indications not successfully treated with other orally available antimicrobials in the past, or for 'step-down' therapy in patients originally treated with intravenous agents. As the usage of these agents expands for serious systemic infections, knowledge of absorptive interactions with fluoroquinolones becomes paramount. Fluoroquinolones are often utilised in dosages and against modestly susceptible pathogens which allow a narrow margin for acceptable decreases in bioavailability. Chelation interactions with multivalent cations can result in inactivation of the fluoroquinolone with ramifications in vitro and in vivo. Chelation interactions have been reported to occur in between 22 and 76% of patients prescribed fluoroquinolones. Concurrent administration of magnesium-aluminum antacids and sucralfate has the greatest effect on the bioavailability of quinolones followed by iron, calcium and zinc. Spacing doses of fluoroquinolones and interactants has been suggested as a method of ensuring adequate quinolone absorption, but this can make optimal administration of the cation interactant difficult, if not impossible.

Absorption↗
PubMed1994

Stability of ciprofloxacin injection in peritoneal dialysis solutions.

The stability of ciprofloxacin 25 mg/L in peritoneal dialysis solutions containing 1.5% and 4.25% dextrose after storage at 4 degrees C for two weeks, 25 degrees C for one week, or 37 degrees C for two days was evaluated. Ciprofloxacin 50 mg was added to 18 2-L bags of peritoneal dialysis solutions, nine containing 1.5% dextrose and nine containing 4.25% dextrose. Three bags of each dialysis solution were stored at 4 degrees C for 14 days, 25 degrees C for 7 days, and 37 degrees C for 2 days. Samples were drawn from each bag, and ciprofloxacin concentrations were measured by high-performance liquid chromatography. Stability was defined as less than 10% decrease from initial concentration. In the solution containing 1.5% dextrose, 87.2% of the ciprofloxacin remained after 14 days of storage at 4 degrees C, 93.4% remained after 7 days of storage at 25 degrees C, and 95.2% remained after 2 days of storage at 37 degrees C. In the solution containing 4.25% dextrose, 89.0% of the ciprofloxacin remained after 14 days of storage at 4 degrees C, 93.7% remained after 7 days of storage at 25 degrees C, and 97.8% remained after 2 days of storage at 37 degrees C. In peritoneal dialysis solutions containing 1.5% and 4.25% dextrose, ciprofloxacin was stable for seven days at 25 degrees C and for 48 hours at 37 degrees C. Ciprofloxacin concentrations after two weeks at 4 degrees C were below 90% of initial concentration.

Ciprofloxacin↗
PubMed1994

Simplified approach to calculation of V, G, and nPCR for monitoring hemodialysis patients.

UNLABELLED: Urea kinetic modeling (KM) permits the calculation of urea volume (VKM), urea generation rate (GKM), and normalized protein catabolic rate (nPCRKM) but requires complex, iterative calculations. Simpler methods for estimation of these parameters (V(est), G(est), nPCR(est)) were compared with those obtained from kinetic modeling. Kinetic modeling was performed on 17 patients using the 3 BUN method, producing 19 data sets. All were within 25% ideal body weight and all had less than 20% difference between VKM and V(est). V(est) was estimated as 0.195 (height) + 0.296 (weight) - 14.01. G(est) was estimated, using interdialytic changes as: [formula: see text] where U is urinary urea excretion rate. nPCR(est) was estimated as: (G(est) x 9.35) + (0.294 x V(est)) x (0.58/V(est)). There was no significant difference (Student's t test) between mean +/- SD V(est) (41.24 +/- 3.86 L) and VKM (40.71 +/- 5.24 L), G(est) (7.23 +/- 1.92 mg/min) and GKM (7.04 +/- 2.10 mg/min), and nPCR(est) (1.12 +/- 0.24 g/kg/day) and nPCRKM (1.10 +/- 0.23 g/kg/day). Correlation between V(est) and VKM was poor (r2 = 0.56, slope = 0.41). Correlations between G(est) and GKM and nPCR(est) and nPCRKM were good (r2 = 0.95, slope = 0.87; and r2 = 0.99, slope = 1.02, respectively). CONCLUSION: Assessment of nutritional status using G(est) and nPCR(est) can be carried out with high degree of accuracy even if V(est) and VKM are not identical.

Aged↗
PubMed1993

Effect of multiple staggered doses of calcium on the bioavailability of ciprofloxacin.

OBJECTIVE: To determine the effect on the relative bioavailability (Fr) of a staggered single dose of ciprofloxacin given two hours after a morning dose of calcium carbonate given three times daily over the three previous days. DESIGN: Thirteen male volunteers participated in this randomized, nonblinded, crossover investigation; 12 subjects were included in the final analysis. SETTING: Data collection and ciprofloxacin administration occurred at Albany Medical Center, a tertiary-care teaching institution. Calcium carbonate administration was on an outpatient basis. RESULTS: For 12 volunteers, the mean +/- SD Fr of ciprofloxacin staggered with calcium was 0.87 +/- 0.23 (noncompartmental model) and 0.98 +/- 0.27 (compartmental model). Other statistically significant findings were a decrease in the time to maximum concentration of ciprofloxacin staggered with calcium in serum compared with ciprofloxacin alone (from 1.76 +/- 0.54 to 1.23 +/- 0.52 h in the noncompartmental model; p < 0.05), and a decrease in the same parameter (from 1.92 +/- 0.96 to 0.77 +/- 0.53 in the compartmental model; p < 0.005). Maximum concentration of ciprofloxacin staggered with calcium was decreased in the noncompartmental model compared with ciprofloxacin alone (from 2.11 +/- 0.72 to 1.60 +/- 0.33, respectively; p < 0.05). The elimination half-life and area under the concentration-time curve of ciprofloxacin were not significantly altered. CONCLUSIONS: Repeated doses of calcium carbonate, administered two hours before ciprofloxacin, did not significantly alter the Fr of this fluoroquinolone.

Adolescent↗
PubMed1993

Peritonitis rates in CAPD patients using the UVXD and O-set systems.

We report experience with O-set and UVXD systems. Sixty-nine O-set patients (34 male; mean age +/- SD = 45.7 +/- 13.2 years) were compared with 54 UVXD patients (27 male; 56.8 +/- 16.8 years). Total (mean +/- SD) experience were 974 (14.1 +/- 10.8) months on O-set and 1010.9 (18.7 +/- 15.7) months on UVXD. Thirty-two O-set patients avoided peritonitis; 37 had 91 episodes. Seventeen UVXD patients avoided peritonitis; 37 had 137 episodes. Peritonitis occurred each 10.7 months (O-set) versus 7.4 months (UVXD), which was significantly different (p = 0.032, Z test; 95% confidence interval = -0.142 to +0.226). There were 18 relapses in 9 O-set patients, 34 in 12 UVXD. Gram-positive organisms caused 58.2% and 66%; gram-negative, 13.2% and 8.8%; and culture negative, 24.2% and 23.4% of peritonitis in O-set and UVXD, respectively. The time to first peritonitis was not different, 7.4 +/- 6.6 months O-set and 7.2 +/- 7.9 months (UVXD). There was no difference in the peritonitis-free period, 13.0 +/- 10.0 months (O-set) and 16.5 +/- 14.3 months (UVXD). There were 1.12 (O-set) and 16.1 (UVXD) cases per patient year, and 10.7 (O-set) and 7.43 (UVXD) patient months per episode. The peritonitis rate odds ratio was 1:1.85 (O-set:UVXD).

Adult↗
PubMed1993

Pharmacokinetics of ciprofloxacin in subjects with varying degrees of renal function and undergoing hemodialysis or CAPD.

The pharmacokinetics of a single, oral dose of 750 mg of ciprofloxacin were studied in 35 subjects with various degrees of renal function (Group 1, Clcr > or = 80 ml/min; Group II, Clcr 50-79 ml/min; Group III, Clcr 10-49 ml/min) and on hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). Blood, urine and CAPD dialysate samples were collected over a period of 48 hours after dosing. Data were fitted using non-linear, least squares regression. The mean Cmax was 3.4 +/- 1.0 mg/l and tmax was 2.3 +/- 0.9 hours. The mean AUC in Group I was 14.7 mg.h/l, Group II was 33.7 (p < 0.001), Group III 63.8 (p < 0.001), HD 57.9 (p < 0.0001) and CAPD 44.3 (p < 0.001). Half-life in Group I was 4.6 h, and was shorter than Group III (11.1 h, p < 0.001), HD (13.4 h, p < 0.001) and CAPD (8.9 h, p < 0.001). Total body clearance and renal clearance demonstrated significant differences also. The dialysis clearance in CAPD patients was 0.53 +/- 0.39 l/h. Peritoneal effluent concentrations varied from 0.6 mg/l during the first exchange, to a peak of 2.2 mg/l during the second, to 0.13 mg/l in the 48 hour (9th) exchange. Dosage adjustments of ciprofloxacin in the presence of renal insufficiency are indicated for subjects with a Clcr < 20 ml/min/1.73m2.

Administration, Oral↗
PubMed1992

Pharmacokinetics of propofol during and after long-term continuous infusion for maintenance of sedation in ICU patients.

The pharmacokinetics of propofol administered as long term infusions were determined in 12 intensive care unit patients (two female; mean age 58 yr, mean weight 66.9 kg) requiring sedation during mechanical ventilation. Patients were recruited after having been administered propofol for 24 h. Blood samples for analysis of propofol were taken during the infusion (mean duration 85.6 h; mean rate 2.58 mg kg-1 h-1) and for up to about 42 h after its termination. The median propofol total body clearance, derived from the apparent steady state propofol blood concentrations during infusion, was 2.11 litre min-1. One patient died during the infusion, from multi-organ failure secondary to a pre-existing septicaemia, and in one other patient no sampling was possible during the first 30 min after infusion; full elimination data were obtained for 10 patients. After termination of the infusion, propofol blood concentrations declined rapidly, with an overall mean decrease of 50% over the first 10 min; thereafter the decline was more gradual. The elimination profile was triphasic in seven patients and biphasic in three patients. Mean half-lives for the three phases were 1.81 (n = 10) min, 70.9 (n = 7) min and 1411 (n = 11) min. There was no apparent trend in the terminal phase half-life with the duration of sampling after infusion.

Adult↗
PubMed1992

Continuous ambulatory peritoneal dialysis: a review of its mechanics, advantages, complications, and areas of controversy.

OBJECTIVE: The primary objective of this article is to review the mechanics, advantages, complications, pharmacokinetics, and future trends of continuous ambulatory peritoneal dialysis (CAPD) as they pertain to pharmacotherapy. DATA SOURCES: Pertinent articles were obtained from an English-language literature search using MEDLINE (1980-1991), Index Medicus (1987-1990), and bibliographic reviews of review articles. Indexing terms included peritoneal dialysis, pharmacokinetics, peritonitis, vancomycin, and fluoroquinolones. DATA SYNTHESIS: All clinical studies comparing organism recovery methods and treatment of peritonitis have methodologic limitations (e.g., comparison of disparate patient groups, different definitions of peritonitis, lack of follow-up, lack of control for sterile cultures) that may affect the reported results. CONCLUSIONS: CAPD is an alternative to hemodialysis for the treatment of endstage renal disease and has many complications, leading to significant morbidity. This indicates that CAPD is not appropriate for all patients. Using blood-culturing techniques to culture for dialysate is most productive, but also the most costly. There are few data to indicate exactly the drugs, doses, and durations of choice for peritonitis. Both intraperitoneal and oral administration appear to be appropriate.

Anti-Infective Agents↗
PubMed1992

Prediction of serum vancomycin concentrations following intraperitoneal loading doses in continuous ambulatory peritoneal dialysis patients with peritonitis.

The pharmacokinetics of vancomycin were studied in continuous ambulatory peritoneal dialysis patients with peritonitis. Six patients received an intraperitoneal loading dose of 15 mg/kg and 4 received an intraperitoneal dose of 25 mg/L. The ability of 2 methods to predict serum concentrations during the loading dose exchange was determined. The mean serum concentration after the exchange was 17.8 +/- 2.2 mg/L in patients receiving the loading dose. The mean dialysis clearance in all patients was 0.94 +/- 0.34 L/h. 66.6 +/- 13.4% of a dose was absorbed into the circulation in 4 h. The volume of distribution was 0.61 +/- 0.46 L/kg, and the half-life for equilibration of vancomycin into the circulation from dialysate was 2.76 +/- 0.94 h. Two methods of predicting serum vancomycin concentrations were tested, with 1 method predicting values significantly different from measured concentrations while the other did not. Serum vancomycin concentrations can be accurately predicted during a loading dose exchange.

Adolescent↗