Search PubMed⌕ Search

Biomedical subjects

R W Force

Publications and source records attributed to R W Force.

34 records · Page 2Linked to original sources
PubMed1995

Topical ciprofloxacin for otorrhea after tympanostomy tube placement.

OBJECTIVE: To evaluate the efficacy, systemic absorption, and safety of ototopically administered ciprofloxacin in children with otorrhea associated with tympanostomy tube placement. DESIGN: Nonrandomized, open-label pilot trial with pharmacokinetic determination of the systemic absorption of ototopical ciprofloxacin. SETTING: A pediatric otolaryngology clinic affiliated with Columbus (Ohio) Children's Hospital. PATIENTS: Patients aged 3 to 8 years were enrolled if they had persistent otorrhea associated with tympanostomy tube placement. Other inclusion criteria were culture of Pseudomonas aeruginosa from the drainage material; failure of previous oral antibiotic therapy; and ability to participate in bone conduction audiometry. INTERVENTION: Participants received 3 drops (approximately 60 microL) of 0.3% ototopical ciprofloxacin hydrochloride (Ciloxan, Alcon Laboratories Inc, Forth Worth, Tex), three times a day, for 14 days. Bone conduction audiometry was performed at baseline and on day 14. Patients were examined on days 7 and 14 for efficacy of treatment (improvement, cure, failure) and adverse effects. On day 7, blood samples were drawn just before and 1 hour after the dose was given. Concentrations of ciprofloxacin were measured by high-performance liquid chromatography, with a 5 ng/mL limit of detection. Telephone follow-up was performed on day 44. Parents were asked about adverse effects at days 7, 14, and 44. RESULTS: Mean duration of ear drainage at baseline was 10.7 months (0.75 to 36 months). Ten of 11 infected ears (nine of 10 patients) were improved or cured at day 7. Ten of 11 ears were completely cured at days 14 and 44. No adverse effects were noted or reported by the children's parents. One child had abnormal bone conduction audiometry results at baseline. The results of bone conduction audiometry on day 14 were normal in all children. Trough concentrations of ciprofloxacin were determined in eight of 10 children; and peak concentrations were determined in seven of 10 children. Ciprofloxacin was not detected in the plasma of any child. CONCLUSION: Topical ciprofloxacin was found to be safe and effective in treating otorrhea in children who did not respond to other treatments.

Administration, Topical↗
PubMed1995

Salivary concentrations of ketoconazole and fluconazole: implications for drug efficacy in oropharyngeal and esophageal candidiasis.

OBJECTIVE: To determine whether salivary concentrations of ketoconazole and fluconazole may explain the apparent disparity between in vitro activity and clinical efficacy observed with these drugs. DESIGN: Healthy subjects received a single oral dose of ketoconazole 400 mg or fluconazole 100 mg in a randomized, crossover fashion. Saliva was collected at 0, 1, 2, 3, 6, 12, and 24 hours. Blood samples were obtained at 2 and 24 hours. Salivary concentrations and plasma concentrations for each drug were determined by HPLC. Minimum inhibitory concentration (MIC) testing was determined in triplicate on 6 clinical isolates of Candida albicans, and times over the median MIC values were calculated. PARTICIPANTS: Eight subjects completed the study. RESULTS: The mean (+/- SD) peak salivary concentration for ketoconazole was 0.119 +/- 0.050 microgram/mL at 3 hours; no subject had a detectable ketoconazole salivary concentration at 24 hours. At 2 and 24 hours, mean ketoconazole plasma concentrations were 7.64 +/- 3.87 and 0.11 +/- 0.05 microgram/mL, respectively. The saliva to plasma concentration ratio at 2 hours was 0.01. The mean peak salivary concentration of fluconazole was 2.56 +/- 0.34 microgram/mL at 3 hours. At 24 hours, the mean salivary concentration was 1.44 +/- 0.33 microgram/mL. At 2 and 24 hours, mean fluconazole plasma concentrations were 4.39 +/- 3.33 and 3.72 +/- 2.83 micrograms/mL, respectively. The saliva to plasma concentration ratio at 2 hours was 0.55. Median MIC values were 0.0625 microgram/mL (range 0.0313-0.125) for ketoconazole and 0.25 microgram/mL (range 0.125-0.5) for fluconazole. Calculated times over which ketoconazole and fluconazole exceeded the median MICs in saliva were approximately 13 and greater than 24 hours, respectively. CONCLUSIONS: After a single oral dose, fluconazole achieved higher salivary concentrations than did ketoconazole. This may explain the increased clinical efficacy of fluconazole in the treatment of oropharyngeal-esophageal candidiasis when compared with ketoconazole.

Administration, Oral↗
PubMed1994

Palatability of 14 over-the-counter antacids.

Although a number of differently flavored antacids have been introduced recently, no blinded comparative palatability evaluations have been conducted since 1977. A comparative, randomized, single-blind evaluation of over-the-counter aluminum and magnesium antacid suspensions was conducted to determine their relative palatability. Thirty healthy volunteers were asked to evaluate 14 antacids for smell, taste, texture, and aftertaste. The study found a statistically significant difference in all rated characteristics of antacids. Mylanta Cherry Creme (score 24.4 out of possible 36) and Mylanta Double Strength Cool Mint Creme (score 24.2) were ranked highest in overall palatability; Riopan Plus 2 (score 18.7) and Di-Gel Lemon Orange (score 18.0) were ranked lowest. The study concluded that the palatability of various antacid suspensions differs markedly and should be considered when selecting an antacid product.

Adult↗
PubMed1993

Loracarbef: a new orally administered carbacephem antibiotic.

OBJECTIVE: To discuss the in vitro activity, pharmacokinetics, clinical efficacy, adverse effects, and relative merits of loracarbef, a new orally administered carbacephem antibiotic. DATA SOURCES: Pertinent literature was identified by a review of selected journals and a MEDLINE search. Additional information was provided by the manufacturer of loracarbef. STUDY SELECTION: All studies that have evaluated the clinical efficacy of loracarbef were included. In vitro studies were included if they used similar methodologies. Additional information was incorporated regarding the chemistry, pharmacokinetics, and adverse effects of loracarbef. DATA SYNTHESIS: Loracarbef has antibacterial activity against most community-acquired respiratory tract, skin and skin structure, and urinary tract pathogens. The drug is well absorbed after oral administration and plasma concentrations achieved in patients are greater than the in vitro minimum inhibitory concentrations for most of the above bacteria. Although the majority of the clinical studies with loracarbef have methodologic deficiencies, loracarbef therapy has demonstrated similar efficacy in the treatment of upper respiratory tract (except otitis media), lower respiratory tract, skin and skin-structure, and urinary tract infections compared with accepted antibiotics. Potential advantages of the new carbacephem may be improved patient compliance with its less frequent dosing schedule (once or twice a day, depending on the infection), and a low incidence of adverse effects. CONCLUSIONS: Preliminary data indicate that loracarbef may be an alternative agent for the treatment of a variety of community-acquired infections. Additional clinical experience and rigorously controlled comparative clinical trials are necessary to enable practitioners to fully define the therapeutic role of loracarbef.

Administration, Oral↗
PubMed1992

Effect of histamine H2-receptor antagonists on vitamin B12 absorption.

OBJECTIVE: To discuss the potential of histamine H2-receptor antagonists (H2RAs) to cause malabsorption of vitamin B12 (cyanocobalamin). DATA SOURCES: Pertinent literature was identified via a MEDLINE search. Journals and references cited in published articles also were used as data sources. STUDY SELECTION: Studies evaluating the effect of H2RAs on vitamin B12 absorption were reviewed. DATA SYNTHESIS: H2RAs decrease acid secretion by the gastric parietal cells. Gastric acid and pepsin produced by these cells are required for the cleavage of vitamin B12 from dietary sources. Intrinsic factor (IF), also produced by gastric parietal cells, is required for vitamin B12 absorption from the gastrointestinal tract. Although H2RAs have not conclusively been shown to decrease IF secretion, studies have demonstrated a significant reduction in food-bound vitamin B12 absorption secondary to decreased acid secretion in patients taking these drugs. CONCLUSIONS: H2RAs have the potential to cause vitamin B12 deficiency. This may be important in patients with inadequate stores of vitamin B12 (e.g., poor diet), particularly those receiving H2RA therapy continuously for more than two years. Healthcare providers should be aware of this potential adverse effect.

Cimetidine↗
PubMed1992

Haemophilus influenzae type B conjugate vaccines.

OBJECTIVE: To review the epidemiology of Haemophilus influenzae type b (Hib) disease, the first Hib vaccine and its limitations, the characteristics and clinical efficacy of the newer conjugate vaccines, and the current recommendations for administration of Hib vaccines. DATA SOURCES: Pertinent literature was identified via a MEDLINE search. Additionally, references cited in published articles were used as data sources. STUDY SELECTION: Studies describing the epidemiology of Hib disease and the efficacy and/or immunogenicity of the Hib vaccines are reviewed. DATA SYNTHESIS: Serious invasive disease secondary to Hib infection causes significant morbidity and mortality in children between the ages of three months and five years. The original Hib vaccine was found to be ineffective in stimulating an adequate immune response in children younger than two years of age. The new Hib conjugate vaccines provide superior efficacy and immunogenicity compared with the original unconjugated vaccine. They stimulate an immune response that is distinctly different from that elicited by the original vaccine. Two vaccine products are currently licensed for use in children as young as two months of age, thus conferring immunity to those children at highest risk for Hib disease. CONCLUSIONS: The new Hib conjugate vaccines provide excellent efficacy and, when used as recommended, may significantly reduce the incidence of invasive Hib disease and its sequelae.

Bacterial Capsules↗
PubMed1992

Reliance on prothrombin time ratios causes significant errors in anticoagulation therapy.

BACKGROUND: The intensity of warfarin anticoagulation in the United States may be inappropriate if the international normalized ratio (INR) is not used, or if the international sensitivity index (ISI) of the thromboplastin is outside the range of 2.2 to 2.6. METHODS: Fifty-three hospital laboratories provided data on the sensitivity of their thromboplastin and whether they reported INR values. Additional data on thromboplastin sensitivity were obtained from 140 laboratories involved in the Stroke Prevention in Atrial Fibrillation study. The three major manufacturers of thromboplastin confirmed the range of thromboplastin sensitivity reported by the laboratories. RESULTS: Of 53 laboratories surveyed, 16 (30%) could not provide ISI data and only 11 (21%) reported INR results. Unlabeled thromboplastin was being used by 20% to 24% of laboratories, and only 8% to 20% were using thromboplastins with an ISI of 2.2 to 2.6. At the time the three manufacturers were contacted, they reported marketing thromboplastins with ISI values from 1.2 to 2.8, but none of the thromboplastins at that time had ISI values between 2.2 and 2.6. CONCLUSION: Warfarin therapy in the United States is managed inappropriately because most laboratories do not report INRs and the variability in thromboplastin sensitivity produces misleading prothrombin time ratio results. Additionally, recent research may require reexamination if INR or ISI data were not provided.

Data Collection↗
PubMedDate not supplied

Pharmacokinetics of fluconazole in young infants.

Intravenous fluconazole is used in the treatment of fungal infections in infants. Little is known, however, about the pharmacokinetics of fluconazole after oral administration in premature infants. Oral fluconazole was administered at a dose of 6 mg/kg. The peak serum concentration (Cmax), area under the serum concentration-time curve (AUC), and apparent clearance ranged from 6.0-13.5 micrograms/ml, 340-636 micrograms.h/ml, and 0.16-0.29 ml/min/kg, respectively. The Cmax and AUC were comparable after oral and intravenous doses of fluconazole. Oral fluconazole was well absorbed and tolerated. The use of oral fluconazole may offer an important alternative to the intravenous therapy; it may improve patient convenience, reduce the need for venous access and decrease complications and the cost of health care.

Administration, Oral↗