Drug-administration sequence does not change pharmacodynamics and kinetics of irinotecan and cisplatin

In this study, 11 patients with solid tumors were randomized to receive irinotecan (CPT-11; 200 mg/m2) as a 90-min i.v. infusion, immediately followed by cisplatin (CDDP; 80 mg/m2) as a 3-h i.v. infusion in the first course and the reversed sequence in the second course or vice versa. No significant differences in any toxicity were observed between the treatment schedules (decrease in absolute neutrophil count, 74.7 +/- 18.3 versus 80.3 +/- 18.0%; P = 0.41). CPT-11 lactone clearance was similar to single agent data and not significantly different between study courses (60.4 +/- 17.1 versus 65.5 +/- 16.3 liter/h/m2; P = 0.66). The kinetic profiles of the major CPT-11 metabolites SN-38, SN-38 glucuronide, 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidinolcarbonyloxycamptothecine (APC), and 7-ethyl-10-[4-N-(1-piperidino)-1-amino]carbonyloxycamptothecine (NPC) were also sequence independent (P > or = 0.20). In addition, CPT-11 had no influence on the clearance of nonprotein-bound CDDP (40.8 +/- 16.7 versus 50.3 +/- 18.6 liter/h/m2; P = 0.08) and the platinum DNA-adduct formation in peripheral leukocytes in either sequence (1.94 +/- 2.20 versus 2.42 +/- 1.62 pg Pt/microg DNA; P = 0.41). These data indicate that the toxicity of the combination CPT-11 and CDDP is schedule independent and that there is no mutual pharmacokinetic interaction

Phase I study of irinotecan and raltitrexed in patients with advanced astrointestinal tract adenocarcinoma

To determine the dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) of irinotecan and raltitrexed given as sequential short infusions every 3 weeks, 33 patients with pretreated gastrointestinal adenocarcinoma (31 colorectal, 2 oesophagogastric) entered this open label dose-escalation study. For the first five dose levels patients received irinotecan 175–350 mg m–2followed by raltitrexed 2.6 mg m–2. Level VI was irinotecan 350 mg m–2plus raltitrexed 3.0 mg m–2, level VII was irinotecan 400 mg m–2plus raltitrexed 2.6 mg m–2; 261 courses were administered. Only one patient at dose levels I–V experienced DLT. At level VI, 5/12 patients experienced DLT: one had grade 3 diarrhoea and lethargy, one had grade 4 diarrhoea and one had lethargy alone. Two others had lethargy caused by disease progression. There was no first-cycle neutropenia. At level VII, 3/6 patients experienced dose-limiting lethargy, one also had grade 3 diarrhoea. Dose intensity fell from over 90% for both drugs at level VI to 83% for irinotecan and 66% for raltitrexed at level VII. Lethargy was therefore the DLT, and level VII the MTD. Pharmacokinetic data showed no measurable drug interaction; 6/30 patients (20%) had objective responses. This combination is active with manageable toxicity. Recommended doses for further evaluation are irinotecan 350 mg m–2and raltitrexed 3.0 mg m–2. © 2000 Cancer Research Campaig

Phase I study of docetaxel in combination with cyclophosphamide as first-line chemotherapy for metastatic breast cancer

This phase I was study conducted to establish the maximum tolerated dose, dose-limiting toxicity, and recommended dose of docetaxel in combination with cyclophosphamide as first-line chemotherapy for metastatic breast cancer. Twenty-six patients were treated with cyclophosphamide (600 mg m−2, intravenous bolus) followed by docetaxel (60, 75 or 85 mg m−2, 1-h intravenous infusion) every 3 weeks. The maximum tolerated dose was docetaxel 85 mg m−2 with cyclophosphamide 600 mg m−2, the dose-limiting toxicity being febrile neutropenia. Grade 4 neutropenia was experienced by all patients, but was generally brief. Otherwise, the combination was well tolerated with few acute and no chronic non-haematological toxicities of grade 3/4. Activity was observed at all dose levels and disease sites, and the overall response rate was 42% (95% confidence interval 22–61%). The pharmacokinetics of docetaxel were not modified by cyclophosphamide coadministration. These findings establish a recommended dose of docetaxel 75 mg m−2 in combination with cyclophosphamide 600 mg m−2 every three weeks for phase II evaluation

Pharmacokinetic drug interactions of antimicrobial drugs:a systematic review on oxazolidinones, rifamycines, macrolides, fluoroquinolones, and Beta-lactams

Like any other drug, antimicrobial drugs are prone to pharmacokinetic drug interactions. These drug interactions are a major concern in clinical practice as they may have an effect on efficacy and toxicity. This article provides an overview of all published pharmacokinetic studies on drug interactions of the commonly prescribed antimicrobial drugs oxazolidinones, rifamycines, macrolides, fluoroquinolones, and beta-lactams, focusing on systematic research. We describe drug-food and drug-drug interaction studies in humans, affecting antimicrobial drugs as well as concomitantly administered drugs. Since knowledge about mechanisms is of paramount importance for adequate management of drug interactions, the most plausible underlying mechanism of the drug interaction is provided when available. This overview can be used in daily practice to support the management of pharmacokinetic drug interactions of antimicrobial drugs