Standards of aminoglycoside therapeutic drug monitoring in a South African private hospital: perspectives and implications

Background: Therapeutic drug monitoring (TDM) is essential to ensure that aminoglycoside peak concentrations are high enough for effective antimicrobial treatment and trough levels are low enough to minimise toxicity. Inappropriate utilisation of TDM may lead to suboptimal therapy, toxicity and waste of resources. This study aimed to investigate the standard of aminoglycoside TDM performed in adult hospitalised patients.Design: An observational, descriptive, cross-sectional study.Setting: A 221-bed private hospital.Participants: All patients, older than 18 years, on intravenous aminoglycosides for more than 48 hours were included.Interventions: None, was observational. A computerised database and patient files were used to obtain the information required for this study. Descriptive statistical analysis was used.Main outcomes measures: Aminoglycoside blood levels and estimated glomerular filtration rate (eGFR) in the patients.Results: One hundred and three (103) patients were included: 65 on gentamicin and 38 on amikacin. Blood levels were performed in only 19 gentamicin (29.23%) and 22 amikacin (57.89%) patients. Trough levels were taken more than 2 hours before the next dose in 12 gentamicin (63.16%) and 12 amikacin (54.54%) patients. The majority of patients (96.92% on gentamicin and 84.21% on amikacin) received once daily doses. TDM was performed in all patients with an estimated glomerular filtration rate (eGFR) lower than 60 mL/min/1.73m2 and in 23.31% of gentamicin patients and 56.76% of amikacin patients with an eGFR higher than 60 mg/min/1.73m2.Conclusions: Incorrect sampling times and unnecessary levels taken in patients with normal renal function indicate a need for aminoglycoside treatment guidelines in the private hospital.Funding: NoneKeywords: Aminoglycosides, Dosing considerations, South Africa, Therapeutic DrugMonitoring, Sampling time

Bone turnover markers in HIV-infected women on tenofovir-based antiretroviral therapy

Background: Tenofovir disoproxil fumarate (TDF) antiretroviral therapy is associated with disruption of the bone turnover process. Objectives: The objective of this study was to determine the association between tenofovir (TFV) plasma concentration and various bone turnover markers and compare these markers in HIV-infected women and HIV-uninfected controls. Method: A cross-sectional sub-study included 30 HIV-infected women on TDF and 30 HIV-uninfected matched participants. Serum calcium (SrCa), serum phosphate (SrP), C-terminal telopeptide (CTx), parathyroid hormone (PTH), alkaline phosphatase (ALP), C-reactive protein (CRP), vitamin D (VitD) and bone mineral density (BMD) were measured. Plasma TFV was assayed on HPLC-MS/MS. The statistical tests applied were Mann–Whitney test, unpaired t-test, analysis of covariance, regression and correlation analysis. Results: In HIV-infected women, no correlation existed between plasma TFV concentration and CTx, PTH, ALP, SrCa, SrP, VitD or BMD (p > 0.05). After adjusting for smoking and alcohol use, ALP (p 0.05). Conclusion: The results indicate possible increased bone turnover at higher TFV concentrations. The normal regular bone turnover processes in HIV-infected women on TDF therapy are altered. Larger studies are warranted to confirm these results

Bergamottin contribution to the grapefruit juice–felodipine interaction and disposition in humans

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109856/1/cptclpt2004537.pd