Ways to Improve Insights into Clindamycin Pharmacology and Pharmacokinetics Tailored to Practice

Given the increase in bacterial resistance and the decrease in the development of new antibiotics, the appropriate use of old antimicrobials has become even more compulsory. Clindamycin is a lincosamide antibiotic approved for adults and children as a drug of choice for systemic treatment of staphylococcal, streptococcal, and gram-positive anaerobic bacterial infections. Because of its profile and high bioavailability, it is commonly used as part of an oral multimodal alternative for prolonged parenteral antibiotic regimens, e.g., to treat bone and joint or prosthesis-related infections. Clindamycin is also frequently used for (surgical) prophylaxis in the event of beta-lactam allergy. Special populations (pediatrics, pregnant women) have altered cytochrome P450 (CYP)3A4 activity. As clindamycin is metabolized by the CYP3A4/5 enzymes to bioactive N-demethyl and sulfoxide metabolites, knowledge of the potential relevance of the drug’s metabolites and disposition in special populations is of interest. Furthermore, drug–drug interactions derived from CYP3A4 inducers and inhibitors, and the data on the impact of the disease state on the CYP system, are still limited. This narrative review provides a detailed survey of the currently available literature on pharmacology and pharmacokinetics and identifies knowledge gaps (special patient population, drug–drug, and drug–disease interactions) to describe a research strategy for precision medicine

Impact of concomitant acid suppressive therapy on pazopanib efficacy and dose reductions in patients with metastatic renal cell carcinoma

PURPOSE: The aim of this study was to investigate the impact of acid suppressive therapy on clinical efficacy and safety of pazopanib in patients with metastatic renal cell carcinoma (mRCC). METHODS: A single-center retrospective study was carried out. Charts of mRCC patients who received pazopanib as first-line treatment were reviewed and concomitant use of proton pump inhibitors (PPI) and histamine 2 receptor antagonists (H2RA) was studied. Two groups of patients were identified, namely patients receiving PPI/H2RA and patients without acid suppressive therapy. Both groups were compared with regard to progression free survival (PFS), overall survival (OS), tumor response, and time to dose reduction of pazopanib. RESULTS: Ninety-one patients were included. Median PFS was 8 months in the PPI/H2RA group vs. 7 months in the no PPI/H2RA group (hazard ratio (HR) 0.76 (95% confidence interval (CI) 0.42-1.35)), p = 0.35. Median OS was 27 months in the PPI/H2RA group vs. 23 months in the no PPI/H2RA group (HR 0.87 (95% CI 0.46-1.66)), p = 0.68. Mean tumor response was 17% (95% CI 8-25%) in the PPI/H2RA group vs. 11% (95% CI 0-21%) in the no PPI/H2RA group, p = 0.52. Median time to first dose reduction was 9 months in both subgroups (HR 1.25 (95% CI 0.65-2.39)), p = 0.51. Median time to second dose (< 600 mg) reduction was 17 months in the PPI/H2RA group vs. 7 months in the no PPI/H2RA group (HR 0.26 (95% CI 0.07-0.89)), p = 0.03. CONCLUSION: In this limited patient series, no evidence of a negative impact of PPI/H2RA on clinical outcome and time to first dose reduction was observed. These results suggest that PPI/H2RA might be considered, when there is a clinical need, in patients treated with pazopanib for mRCC. However, a prospective study is warranted to confirm these results.status: publishe