Medication prescribing patterns in ambulatory haemodialysis patients: comparisons of USRDS to a large not-for-profit dialysis provider.

BACKGROUND: End-stage renal disease (ESRD) patients are prescribed numerous medications. The United States Renal Data System (USRDS) reported on medication prescribing patterns in 1998. Since then, several new medications, treatment guidelines and recommendations have been introduced. The objective was to analyse and compare haemodialysis (HD) patient medication prescribing patterns between the Dialysis Clinic, Inc. (DCI) database and the USRDS report. METHODS: Point-prevalent (01/01/03) medication use data from the DCI national database was obtained. Data collected included patient demographics, reason for and duration of ESRD, and medication listed on profile. All medications were classified similar to the USRDS and by where taken (clinic vs home). Medication prescribing patterns were compared between DCI and USRDS databases. Comparisons between age groups (<65 and >or=65 years) and diabetic status [diabetes mellitus (DM) vs non-DM] were made. RESULTS: There were 128 477 medication orders categorized in 10 474 patients. DCI patient demographics were similar to present USRDS patients except for fewer Hispanics (P<0.001). Patients were prescribed 12.3+/-5.0 (median 12) different medications (2.6+/-1.4 clinic medications and 10.0+/-4.5 home medications). This is higher than reported by USRDS (median 9 medications). Patient age did not influence number of medications used (P = 0.54). DM patients are prescribed more medications than non-DM (13.3+/-5.0 DM vs 11.6+/-4.8 non-DM; P<0.00001). All medication class prescribing patterns were markedly different. CONCLUSION: The data suggest that medication prescribing patterns in HD patients have changed. The audit identified appropriate and questionable prescribing patterns. Various prescribing patterns identified areas for improvement in care (e.g. increased use of aspirin, beta-blockers and hyperlipidaemia medications) and areas requiring further investigation (e.g. high use of anti-acid, benzodiazepine and non-aluminum/non-calcium phosphate-binding medications).

Gentamicin pharmacokinetics during slow daily home hemodialysis.

BACKGROUND: Gentamicin is commonly used in hemodialysis patients. Gentamicin pharmacokinetics during traditional hemodialysis have been described. Slow daily home (SDH) hemodialysis (7 to 9 hours a day/6 days a week) use is increasing due to benefits observed with increased hemodialysis. We determined gentamicin pharmacokinetics for SDH hemodialysis patients. METHODS: Eight patients (four male and four female) received a single intravenous dose of 0.6 mg/kg gentamicin post-hemodialysis. Blood samples were collected at 5, 10, 15, 30, and 60 minutes after dose. The next day patients underwent a typical SDH hemodialysis (high-flux F50NR dialyzer) session. Blood samples were taken at 0, 5, 15, 60, 120, 240, 360, 480 minutes during and 15, 30 and 60 minutes post-hemodialysis. Baseline and 24-hour urine samples were collected. Pharmacokinetic parameters were calculated assuming a one-compartment model. RESULTS: Patients were 42.5 +/- 13.1 years old (mean +/- SD). Inter-, intra-, and post-hemodialysis collection periods were 17.0 +/- 2.1 hours, 8.1 +/- 0.4 hours, and 1.1 +/- 0.1 hours, respectively. Intra-, and interdialytic gentamicin half-lives were different (intradialytic, 3.7 +/- 0.8 hours; interdialytic, 20.4 +/- 4.7 hours; P < 0.0001). Hemodialysis clearance accounted for 70.5% gentamicin total clearance. Renal clearance correlated with glomerular filtration rate (GFR) (renal clearance=1.2 GFR; r2=0.98; P < 0.001). Mean peak and trough of hemodialysis concentrations were 1.8 +/- 0.6 microg/mL and 0.5 +/- 0.2 microg/mL, respectively. Post-hemodialysis rebound was 3.1 +/- 8.8% at 1 hour. CONCLUSION: Pharmacokinetic model predicts 2.0 to 2.5 mg/kg dose gentamicin post-hemodialysis would provide peak (1 hour post-dose) and trough (end of SDH hemodialysis session) concentrations of 6.0 to 7.5 microg/mL and 0.7 to 0.8 microg/mL, respectively. This would provide adequate coverage for most gram-negative organisms in SDH hemodialysis patients.

Factors associated with medication-related problems in ambulatory hemodialysis patients.

BACKGROUND: Hemodialysis (HD) patients are at risk for medication-related problems. Patient characteristics associated with the number of medication-related problems in HD patients have not been investigated. METHODS: Patient records were reviewed to identify medical problems, prescribed medications, medication indication(s), and medication-related problems. Medication classes and medication-related problems were compared between patients with and without diabetes mellitus (DM). Correlations were performed to determine whether associations exist between medication-related problems, number of medications, number of medication doses per day, number of comorbid conditions, patient age, and duration of end-stage renal disease while controlling for DM status. RESULTS: Medical records of 133 patients were evaluated. Patients were 60.5 +/- 15.2 years old, prescribed 11.0 +/- 4.2 medications, and had 6.0 +/- 2.3 comorbidities. Medication-related problems were identified in 97.7% of patients. Four hundred seventy-five medication-related problems were identified, averaging 3.6 +/- 1.8 medication-related problems per patient. Patients with DM had more medication-related problems identified than those without DM (303 versus 172 medication-related problems, respectively; P < 0.05). Medication-related problems correlated positively with number of patient comorbidities (P < 0.001). CONCLUSION: Medication-related problems are prevalent in virtually all HD patients. The number of medication-related problems in an individual patient increases as the number of comorbid conditions increases. The most frequent medication-related problems were drug without indication (30.9%), laboratory (27.6%), indication without drug use (17.5%), and dosing errors (15.4%). Patients with DM are at increased risk for medication-related problems. Health care providers taking care of HD patients should be aware of this problem, and efforts to avoid or resolve medication-related problems should be undertaken at all HD clinics.