A Double-Blind, Randomized Study of Two Different Dosage Regimens of Intravenous Dolasetron in Patients Receiving High-Dose Cisplatin Chemotherapy

This study compared the antiemetic efficacy and safety of two different intravenous (IV) dolasetron dosing regimens in patients receiving their first course of high-dose (≧80 mg/m²) cisplatin. Of 30 patients enrolled, 14 received a single IV dolasetron dose (0.6 mg/kg) before cisplatin and 16 received a multiple IV dose regimen (0.6 mg/kg x 3) given before and after cisplatin. Complete plus major responses were achieved by 71% (10/14) of patients who received single-dose dolasetron and by 50% (8/16) of those who received the multiple-dose regimen. Forty-three percent (6/14) of patients who received the single dose liad a complete response compared with 25% (4/16) who received multiple doses. Multiple doses resulted in less nausea at 24 hr following cisplatin; however, differences were not statistically significant. Both regimens were well tolerated, with mild headache (33%) and diarrhea (13%) the most common adverse events. This study demonstrated that a single 0.6-mg/kg dose of dolasetron given before chemotherapy provides equivalent antiemetic efficacy to three 0.6-mg/kg doses given before and after high-dose cisplatin chemotherapy; thus, there was no additional antiemetic benefit by using the multiple-dose regimen.     

Phase I and pharmacologic study of 7- and 21-day continuous etoposide infusion in patients with advanced cancer

 Purpose. This phase I study was undertaken to evaluate the safety and tolerability of prolonged infusional etoposide, and to evaluate its pharmacokinetic/pharmacodynamic profile in patients with advanced cancer. Methods. A group of 17 patients received a 7-day infusion of etoposide (schedule A) every 21 days at doses from 30 to 75 mg/m² per day, and a second group of 37 patients a 21-day infusion (schedule B) every 28 days at doses from 18 to 40 mg/m² per day. Patients had a median Karnofsky performance status (PS) of 80%, and 34 patients had no prior chemotherapy. Etoposide concentrations at steady state (Css) and other pharmacokinetic parameters (plasma clearance, CLp; area under the curve, AUC) were determined during the first treatment cycle. Correlation coefficients were calculated to measure the relationship between variables. Results. Myelosuppression was the major toxicity, and was associated with three deaths. The maximum tolerated dose due to neutropenia was 75 mg/m² per day for schedule A and 40 mg/m² per day for schedule B. There was significant interpatient pharmacokinetic variability in both infusional schedules. Even though etoposide dose levels did not significantly correlate with plasma levels, the Css was ≥1 μg/ml in the majority of the patients. A significant correlation between AUC and neutrophil absolute decrease was noted only in schedule B (r=0.56,  P=0.003). There were several marginal relationships in schedule B: PS versus Css (r=0.31,  P=0.058), PS versus AUC (r=−0.38; P= 0.058) and age versus CLp (r=−0.31, P=0.057). Conclusion. Overall, significant correlations were found for several hematologic variables and etoposide dose levels, but not with the Css values. One major problem with the application of pharmacodynamic models to predict hematologic toxicity in clinical practice is the presence of significant interpatient variability. Received: 3 April 1995/Accepted: 6 December 1995     

Randomized double-blind comparison of three dose levels of intravenous ondansetron in the prevention of cisplatin-induced emesis

The selective 5-hydroxytryptamine₃ (5HT₃) antagonist ondansetron has been shown to be an effective antiemetic in patients receiving cisplatin chemotherapy. This double-blind study compared the efficacy and safety of three doses of intravenous ondansetron in the prevention of nausea and vomiting associated with high-dose (100 mg/m²) cisplatin chemotherapy. A total of 125 patients were randomized (111) to receive 0.015, 0.15, or 0.30 mg/kg every 4 h for a total of 3 doses. All patients were monitored for emetic episodes, adverse events, and laboratory safety parameters for 24 h following cisplatin administration. The 0.15-mg/kg dose was superior to the 0.015-mg/kg dose with respect to the median number of emetic episodes (P=0.033) and complete response (no emetic episodes,P=0.005). No statistically significant difference was found between the 0.15 and the 0.30-mg/kg groups. The most common adverse event was headache. Three 0.15-mg/kg doses of intravenous ondansetron are safe, effective, and adequate for the control of cisplatin-induced emesis.This study was supported by a grant from Glaxo Inc.     

Chemotherapy-induced emesis: management of early and delayed emesis in milder emetogenic regimens

 The objective of the present study was to examine the problem of the control of nausea and vomiting induced by non-cisplatin containing cyclophosphamide-based chemotherapy regimens in breast cancer patients. This was randomized, double-blind, parallel-group and placebo-controlled study comparing the efficacy of three antiemetic therapeutic regimens (ondansetron for 3 days, ondasetron plus metoclopramide, and ondansetron given in a single dose) in breast cancer patients receiving cyclophosphamide-based chemotherapy regimens on an outpatient basis. Both the primary and the secondary efficacy were measured. The primary efficacy variable was the number of emetic episodies (considering early and delayed emesis). The secondary efficacy variable measured was the quality of life. Two-by-two tables using the chi-square test and relative-risk concept were elaborated for statistical analysis. There was no difference between high-dose ondansetron and ondansetron plus metoclopramide among patients given CMF (cyclophosphamide, methotrexate, 5-fluorouracil). The single-dose ondansetron regimen showed the worst results. In patients given an FEC regimen (cyclophosphamide, epirubicin, 5-fluorouracil) the antiemetic efficacy was best for the high-dose ondansetron regimen, followed by the ondansetron plus metoclopramide regimen, and was worst for single-dose ondansetron administration. Despite the use of different antiemetic schedules, nausea and emesis are significant problems in patients receiving cyclophosphamide-based chemotherapy. Their adequate control should be the aim of any antiemetic approach. Received: 23 September 1995/Accepted: 25 January 1996     

Prevention of apomorphine- or cisplatin-induced emesis in the dog by a combination of methylnaltrexone and morphine

Purpose: Morphine can have either an emetic or an antiemetic effect. The emetic effect of morphine can be blocked by methylnaltrexone (MNTX), a quaternary opioid antagonist with peripheral action. In this study, we tested the hypothesis that administering MNTX to block the peripheral emetic effect of morphine would unmask the central antiemetic effect of the morphine. The net result, we hypothesized, would be a reduction in apomorphine- or cisplatin-induced emesis. Methods: MNTX 0.25 mg/kg and morphine 1 mg/kg were administered to conscious dogs which were then challenged with the potent emetic agents apomorphine or cisplatin. Emesis was assessed by the presence of characteristic retching motions accompanied by the regurgitation of gastric contents. Results: We observed that apomorphine challenges of 0.1 mg/kg and of 0.03 mg/kg produced 100% emesis in control animals. After pretreatment with MNTX and morphine, the frequency of emesis with the larger dose of apomorphine was reduced to 50% and with the smaller dose to 22%. MNTX alone did not block apomorphine-induced emesis. In animals challenged with cisplatin 3 mg/kg, the emetic response was 100%. Emesis did not occur in animals pretreated with MNTX 0.25 mg/kg and morphine 1 mg/kg before cisplatin. Conclusions: Our results demonstrate that MNTX combined with morphine reduces apomorphine-induced emesis and blocks cisplatin-induced emesis. These results support the hypothesis that the emetic effect of morphine is peripheral and its antiemetic action is central. In combination, MNTX and morphine may have a clinical role in the treatment of chemotherapy-induced emesis. Received: 28 August 1997 / Accepted: 12 November 1997     

Formulation and stability of busulfan for intravenous administration in high-dose chemotherapy

 The bifunctional alkylating agent busulfan (Bu) was solubilized in a cosolvent mixture of anhydrous dimethylacetamide (DMA), polyethylene glycol 400 (PEG400), and water at a ratio of 1:2:2 (v/v/v), to achieve a Bu concentration of 3 mg/ml, a preparation that would be suitable for parenteral administration in high-dose chemotherapy preceding bone marrow transplantation. The complete formulation was stable for more than 54 h at room temperature (RT, 22° C). An accelerated stability study of Bu in anhydrous DMA or DMA/PEG400 (1:2) as stock solutions indicated shelf-lives of 191 and 180 days respectively, at RT, and 8.2 and 7.5 years, respectively, at 4° C. Although the complete formulation with Bu was very hypertonic, hemolysis studies indicated that the formulation would be safe for intravenous (i.v.) administration, since it would be rapidly diluted to harmless tonicity levels in the blood. Cytotoxicity studies of the complete formulation in vitro proved that Bu retained its activity when dissolved in the complete vehicle. A preliminary pharmacokinetic study in a rodent model after the i.v. administration of Bu at a dose of 1 mg/kg body weight yielded high plasma concentrations of Bu for at least 5 h after injection. Received: 22 November 1994/Accepted: 14 May 1995     

A controlled,dose-comparison study of granisetron for nausea and vomiting induced by cancer chemotherapy in children

Background We investigated the efficacy and safety of granisetron in 40 pediatric oncology patients who received identical chemotherapy regimens for three courses. Methods During the first course, the emetogenicity of each chemotherapy regimen was evaluated without granisetron. Next patients received one of two doses of intravenous granisetron, i.e. 20 or 40 mcg/kg during the second and third course of chemotherapy in a cross-over fashion. Results Out of the 40 patients, two children had no emetic episode during the 24 hour period following commencement of the first course of chemotherapy. Whereas, 23 patients receiving 20 μ/kg granisetron, and 22 patients receiving 40 μ/kg, obtained complete response (no emetic episode during the 24 hour period following commencement of chemotherapy) in the second or third course. When patients received 20 or 40 μ/kg of granisetron, all measured efficacy parameters were superior in comparison to the period when they were receiving no granisetron. There was no significant difference in the antiemetic effect between the two doses of granisetron. However, a dose-related improvement in efficacy was observed with granisetron in a certain subset of patients; that is, 4 of the 10 patients receiving 20 μ/kg, who had responded poorly with respect to nausea and vomiting, showed a complete or major response when the dose was increased to 40 μ/kg. One child developed somnolence. No other adverse events were observed. Conclusion Granisetron is an effective and safe antiemetic for children receiving intensive chemotherapy regimens containing cisplatin, cyclophosphamide or methotrexate. When comparing the two doses of 20 and 40 μ/kg, 40 μ/kg appeared more effective; although the difference was not statistically significant.     

High-dose intravenous metoclopramide versus combination high-dose metoclopramide and intravenous dexamethasone in preventing cisplatin-induced nausea and emesis: a single-blind crossover comparison of antiemetic efficacy

We tested the safety and antiemetic effectiveness of intravenous (IV) dexamethasone (DXM) as an adjunct to high-dose IV metoclopramide (MCP) to prevent nausea and vomiting induced by high-dose cisplatin chemotherapy. Response was determined by using objective and subjective criteria. Thirty patients were randomly assigned to receive MCP alone at a dose of 2 mg/kg IV for three doses or the same dose of MCP plus 20 mg of DXM IV for three doses. Twenty evaluable patients received a second course of cisplatin and were crossed over to the opposite arm. Study results did not show a statistically significant advantage of combination MCP plus DXM over MCP alone using strict objective criteria for antiemetic response. However, patients subjectively preferred MCP plus DXM over MCP alone by nearly a 6:1 ratio, regardless of the randomization sequence. Although the addition of DXM does not appear to objectively improve emetic protection with high-dose MCP, we recommend MCP plus DXM to prevent nausea and vomiting induced by high-dose cisplatin chemotherapy when the use of steroids is not contraindicated, in view of patient preference for the combination.     

A pharmacogically guided phase I study of carboplatin in combination with methotrexate and vinblastine in advanced urothelial cancer

 Carboplatin is an alternative for cisplatin in the treatment of urothelial cancers. A pharmacologically guided phase I study of carboplatin in combination with methotrexate (30 mg/m²) and vinblastine (4 mg/m²) was conducted in ten patients by increment of the area under the plasma concentration versus time curve (AUC) for ultrafilterable carboplatin using the Calvert formula. The maximal tolerated AUC was 5 mg ml^-1 min, with neutropenia being the dose-limiting toxicity. There was a significant linear correlation between the percentage of decrease in neutrophil count and the carboplatin AUC. Determination of the glomerular filtration rate by the isotopic method allowed us to adapt the dose of carboplatin given to patients suffering from urothelial cancer, who frequently have impaired renal function. The recommended AUC for phase II study is 4 mg ml^-1 min. Received: 9 May 1994/Accepted: 16 August 1994     

Methylprednisolone as an antiemetic drug

Summary To evaluate the antiemetic efficacy of high-dose methylprednisolone (MP) in previously untreated cancer patients receiving cisplatin (CPDD) for the first time, we performed a randomized double blind study. MP or a placebo (PLB) was administered six times during each course of chemotherapy. The first dose was 500 mg and all others, 250 mg. A total of 30 patients were included and studied during three chemotherapy courses. No significant differences were found between the MP- and PLB-treated group with respect to the number of emetic episodes and degree of nausea. There was also no difference for pain, appetite, nausea, vomiting, sleep, weakness, or energy level as analyzed by the use of a Linear Analog Self-Assessment (LASA) scale up to 7 days after chemotherapy. On the other hand, the assessment of well-being, anxiety, and mood favored the PLB group.We conclude that high-dose MP used as a single antiemetic medication against CPDD-induced nausea and vomiting is of only limited value or none at all.     

Pharmacokinetic studies of 13-cis-retinoic acid in pediatric patients with neuroblastoma following bone marrow transplantation

 A phase I clinical trial of 13-cis-retinoic acid (cis-RA) was undertaken to determine the maximally tolerated dose (MTD) and pharmacokinetics (PK) of cis-RA following bone marrow transplantation (BMT) in children with high-risk neuroblastoma. Mean peak serum levels of cis-RA in 31 pediatric patients ranged from 4.9 to 8.9 μM following doses of 100–200 mg/m² per day, divided into two doses every 12 h administered orally. The PK of cis-RA obeyed a single-compartment model following first-order absorption in the majority of patients. A linear increase in the mean peak serum levels and area under the time-concentration curve (AUC) with increasing dose was observed. The average half-lives of absorption and elimination were 1.0 and 5.8 h, respectively. At the MTD of 160 mg/m² per day, the mean cis-RA peak serum concentration was 7.2±5.3 μM. AUC values were not altered significantly during a 2-week course of treatment or over a long period of multiple courses. Levels of trans-retinoic acid, a metabolite of cis-RA, remained low but were similar on days 1 and 14, whereas the 4-oxo-13-cis-RA metabolite had increased in 64% of patients by day 14. Peak serum cis-RA concentrations correlated with clinical toxicity as grade 3 to 4 toxicity was seen in 44% of patient-courses (8/18) with peak serum levels ≥10 μM, but only 13% (12/96) with peak serum levels <10 μM. These results show that cis-RA given at 160 mg/m² to children achieved serum concentrations known to be effective against neuroblastoma in vitro, and the PK for cis-RA differs from that reported for trans-retinoic acid in children. Received: 6 February/Accepted: 29 January 1996     

Determination of vinca alkaloids in human plasma by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry

 A sensitive assay was developed for the quantitation of vinblastine, desacetylvinblastine and vincristine using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS). Analyses were performed on an Ultrasphere C₁₈ microbore column using ammonium acetate as mobile phase. The calibration curves were linear across the range of 0.51–4.00 ng/ml (0.63–4.93 nM) for vinblastine, 0.74–3.93 ng/ml (0.96–5.11 nM) for desacetylvinblastine and 0.30–3.95 ng/ml (0.36–4.79 nM) for vincristine. Vinca alkaloid concentrations were measured with an accuracy and precision within 11%. This assay could be implemented to determine the plasma concentrations for pharmacokinetic studies of vinblastine, desacetylvinblastine and vincristine in conjunction with clinical trials. Received: 15 December 1995 / Accepted: 16 June 1996     

Quantitative relationship between pharmacokinetics of unchanged cisplatin and nephrotoxicity in rats: importance of area under the concentration-time curve (AUC) as the major toxicodynamic determinant in vivo

 Purpose: The major pharmacokinetic parameters of unchanged cisplatin (CDDP) related to nephrotoxicity were evaluated in rats in vivo using a pharmacodynamic model. Methods: CDDP was administered according to various dosing schedules (single bolus, intermittent bolus, or continuous infusion). Unchanged CDDP in plasma and urine was quantified using high-performance liquid chromatography (HPLC). The pharmacokinetics were assessed by model-independent methods. The relationship between pharmacokinetics and BUN levels was evaluated using a sigmoid maximum response (E_max) model. Results: Unchanged CDDP showed linear pharmacokinetics after single bolus injections of 1 to 5 mg/kg CDDP. Nephrotoxicity was ameliorated following intermittent bolus injection (1 mg/kg per day for 5 days) and continuous infusions (over 2 and 3 h) of the same CDDP doses (5 mg/kg), although these dosing schedules did not change the area under the concentration-time curve (AUC), total clearance (Clt), urinary excretion of unchanged CDDP or kidney platinum levels significantly. The maximum BUN level, as a nephrotoxicity marker, showed dose-related increases after single bolus injection of 1 to 5 mg/kg CDDP and after 3-h infusion of 5 to 25 mg/kg. The pharmacodynamic relationship between the maximum BUN level and C_max and between the maximum BUN level and AUC were apparently different between single bolus injection and 3-h infusion. The maximum BUN level was related to the AUC calculated by plasma concentrations of unchanged CDDP greater than the threshold level (AUC_>Cmin), a relationship most successfully described by the signoid E_max model, regardless of CDDP dose and schedule. The plasma threshold level of unchanged CDDP was determined as 0.9 μgPt/ml in rats. Conclusions: The present results substantiated the importance of C×T (AUC) value as an indicator of CDDP-induced nephrotoxicity in vivo as well as of tumor cell-killing effect of CDDP in vitro. The AUC_>Cmin of unchanged CDDP was found to be an important pharmacokinetic parameter predicting CDDP nephrotoxicity. Received: 12 February 1996 / Accepted: 5 September 1996     

Tropisetron plus haloperidol to ameliorate nausea and vomiting associated with high-dose alkylating agent cancer chemotherapy

Tropisetron is a novel antiserotoninergic drug with potent and specific activity against cancer chemotherapy-induced emesis. High-dose cyclophosphamide or high-dose melphalan are chemotherapeutic regimens associated with severe nausea and vomiting refractory to current antiemetic medications. We compared in a randomised open label study the antiemetic efficacy of tropisetron and alizapride in a first group of 32 consecutive patients treated with high-dose alkylating agent chemotherapy with or without autologous bone marrow transplantation. Tropisetron was more effective than alizapride in reducing vomiting episodes. In the first 24 h of treatment the median number of episodes in patients treated with tropisetron was 5 compared with 9 episodes in the alizapride group (P = 0.005). In the 72 h study period the median number of emetic episodes was 6 in the tropisetron group and 12 in the alizapride group (P = 0.004). In a second group of 26 consecutive patients, a combination of tropisetron plus haloperidol, a dopamine antagonist, was employed for prevention of emesis. This combination was more effective than tropisetron as single agent in preventing emetic episodes, as the median number of emetic episodes in the 72 h of observation was only 3, while they were 6 in the tropisetron group. The side-effects of tropisetron were mild and reversible upon discontinuation of the drug. We conclude that tropisetron is an effective antiemetic drug when employed in high-dose alkylating agent chemotherapy, and that its activity is potentiated by the association with haloperidol.     

Improved prevention of moderately emetogenic chemotherapy-induced nausea and vomiting with palonosetron, a pharmacologically novel 5-HT3 receptor antagonist: results of a phase III, single-dose trial versus dolasetron

BACKGROUND: Palonosetron, a highly selective and potent 5-HT(3) receptor antagonist with a strong binding affinity and a long plasma elimination half-life (approximately 40 hours), has shown efficacy in Phase II trials in preventing chemotherapy-induced nausea and vomiting (CINV) resulting from highly emetogenic chemotherapy. The current Phase III trial evaluated the efficacy and safety of palonosetron in preventing acute and delayed CINV after moderately emetogenic chemotherapy. METHODS: In the current study, 592 patients were randomized to receive a single, intravenous dose of palonosetron 0.25 mg, palonosetron 0.75 mg, or dolasetron 100 mg, 30 minutes before receiving moderately emetogenic chemotherapy. The primary efficacy endpoint was the proportion of patients with a complete response (CR; defined as no emetic episodes and no rescue medication) during the first 24 hours after chemotherapy. Secondary endpoints included assessment of prevention of delayed emesis (2-5 days postchemotherapy). RESULTS: In the current study, 569 patients received study medication and were included in the intent-to-treat efficacy analyses. CR rates during the first 24 hours were 63.0% for palonosetron 0.25 mg, 57.1% for palonosetron 0.75 mg, and 52.9% for dolasetron 100 mg. CR rates during the delayed period (24-120 hours after chemotherapy) were superior for palonosetron compared with dolasetron. Adverse events (AEs) were mostly mild to moderate and not related to study medication, with similar incidences among groups. There were no serious drug-related AEs. CONCLUSIONS: A single dose of palonosetron is as effective as a single dose of dolasetron in preventing acute CINV and superior to dolasetron in preventing delayed CINV after moderately emetogenic chemotherapy, with a comparable safety profile for all treatment groups.     

Stratified, randomized, double-blind comparison of intravenous ondansetron administered as a multiple-dose regimen versus two single-dose regimens in the prevention of cisplatin-induced nausea and vomiting.

PURPOSE: This study compares the efficacy and safety of two single-dose regimens with the approved three-dose regimen of ondansetron in the prevention of cisplatin-induced emesis. PATIENTS AND METHODS: This multicenter study was a stratified, randomized, double-blind, and parallel group design. Chemotherapy-naive inpatients were randomized to receive intravenous (IV) ondansetron (Zofran; Glaxo Inc, Research Triangle Park, NC) 0.15 mg/kg times three doses, every 4 hours or a single 8-mg or 32-mg dose followed by two saline doses that began 30 minutes before cisplatin administration. Cisplatin (high-dose > or = 100 mg/m2 or medium-dose 50 to 70 mg/m2) was given as a single infusion (< or = 3 hours). Patients were monitored for emetic episodes, adverse events, and laboratory safety parameters for 24 hours after cisplatin administration. RESULTS: A total of 699 patients (359 high-dose, 340 medium-dose) were enrolled. Of these, 618 were assessable for efficacy (15 ineligible, 66 protocol deviations). The 32-mg dose was superior to the 8-mg single dose with regard to total number of emetic episodes (high-dose, P = .015; medium-dose, P < .001), complete response (no emetic episodes: high-dose, 48% v 35%; P = .048; medium-dose, 73% v 50%; P = .001) and failure rate (> 5 emetic episodes, withdrawn or rescued: high-dose, 20% v 34%; P = .018; medium-dose, 9% v 23%; P = .005). The 32-mg single dose was also superior to the 0.15 mg/kg times three dose regimen with regard to total number of emetic episodes (medium-dose, P = .033) and failure rate (high-dose, 20% v 36%; P = .009; medium-dose, 9% v 22%; P = .011). Ondansetron was well tolerated. The most common adverse event was headache. An approximate 10-fold increase in the incidence of clinically significant transaminase elevations was observed in the high-dose versus medium-dose cisplatin strata (aspartate aminotransferase [AST], 6.5% v 0.7%; serum alanine aminotransferase [ALT], 5.0% v 0.3%). CONCLUSION: A 32-mg single dose of ondansetron is more effective than a single 8-mg dose and is at least as effective as the standard regimen of 0.15 mg/kg times three doses in the prevention of cisplatin-induced acute emesis.     

Relationship between pharmacokinetics of unchanged cisplatin and nephrotoxicity after intravenous infusions of cisplatin to cancer patients

 Purpose: The relationships between pharmacokinetic parameters of unchanged cisplatin (CDDP) and several markers for nephrotoxicity after CDDP infusion (80 mg/m²) over 2 and 4 h were quantitated in patients with various cancers (lung, stomach and colon cancers and mediastinal tumor). Methods: Plasma and urinary levels of unchanged CDDP were measured using a specific high-performance liquid chromatography method. Pharmacokinetic parameters were calculated according to the model-independent method. The nephrotoxicity markers, blood urea nitrogen (BUN), serum creatinine (SCr), plasma and urinary β₂-microglobulin (BMG_p and BMG_u), urinary N-acetyl-β-D-glucosaminidase (NAG) and creatinine clearance (CCR) were monitored for 30 days following CDDP administration. Results: The maximum plasma concentration (C_max), maximum urinary excretion rate (dAe/dt_max), area under the plasma concentration-time curve from time zero to infinity (AUC), cumulative amount excreted in urine from time zero to infinity (Ae), total clearance (Clt), renal clearance (Clr) and plasma half-life (t_1/2) of unchanged CDDP were not significantly different between the 2-h and 4-h infusion schedules. The values of the nephrotoxicity markers changed significantly following CDDP administration, suggesting that CDDP chemotherapy (80 mg/m²) caused nephrotoxicity. The C_max of unchanged CDDP was the most informative pharmacokinetic parameter for nephrotoxicity. C_max was related to maximum BUN, maximum SCr and minimum CCR levels in 27 CDDP treatments according to an exponential model. Conclusion: In order to attain more effective CDDP chemotherapy with minimum nephrotoxicity, the present pharmacokinetic and pharmacodynamic studies suggest that the C_max or steady-state plasma level of unchanged CDDP should be maintained between 1.5 and 2 μg/ml in a standard continuous infusion schedule over 2 h and 4 h. Received: 2 May 1995/Accepted: 25 March 1996     

A randomized trial of high dose bolus metoclopramide versus low-dose continuous infusion metoclopramide in the prevention of cisplatin-induced emesis

We compared the antiemetic efficacy of metoclopramide in a bolus low-dose infusion schedule to that of metoclopramide given in a conventional high-dose bolus schedule in a randomized crossover trial. Thirty-two treatment courses in 16 patients receiving cisplatin chemotherapy were evaluable. The metoclopramide regimen was either 2 mg/kg i.v. bolus, then 20 mg/h by infusion for 4 h, or 2 mg/kg i.v. bolus every 2 h for three doses. Dexamethasone 20 mg i.v. and diphenhydramine 50 mg i.v. were also given. Antiemetic efficacy was assessed by a questionnaire. There were no differences in antiemetic efficacy between the metoclopramide regimens. With either program, 75% of patients were emesis-free, 13% had mild symptoms, and 13% had moderate symptoms (greater than two emetic episodes). The infusion metoclopramide regimen was 30% less expensive than the bolus schedule in our pharmacy. Thus, we recommend low-dose metoclopramide infusion as a less expensive, equally effective alternative to high-dose bolus regimens for antiemetic treatment.     

Does parenteral magnesium sulfate have an antiemetic effect during chemotherapy with cis-platinum?

Summary Cisplatin is a chemotherapeutic agent with a high emetic potential; it can lead to hypomagnesemia, which is caused by a renal wasting. Because of beneficial effects of magnesium in the therapy of motor disorders of the upper gastrointestinal tract and its sedative, anticonvulsive effect in eclampsia, we tested parenteral magnesium sulfate as a potential antiemetic in patients receiving cisplatin. A prosepctive, randomized, double-blind, crossover study was carried out in 20 patients receiving 60 mg/m² cisplatin. A standard antiemetic regimen consisting of a single dose of 10 mg diazepam and five times 0.5 mg/kg metoclopramide (every 2 h) was used. Simultaneously, 8 g magnesium sulfate or isotonic sodium chloride was infused over 4.5 h. The efficacy of magnesium was analyzed with an emetic score system; no difference was found between magnesium sulfate and sodium chloride. Only two patients were hypomagnesemic, and they had a better emetic score with the magnesium infusion. We conclude that the i.v. administration of magnesium during cisplatin therapy has no antiemetic effect, at least in normomagnesemic patients.     

Effect of glutathione depletion on the cytotoxicity of cisplatin and iproplatin in a human melanoma cell line

 Previous studies from our laboratory have indicated that glutathione (GSH) may affect the cytotoxicity of iproplatin to a greater extent than four other platinum agents tested including cisplatin. Therefore we studied the effect of GSH depletion by buthionine sulfoximine (BSO) on the cytotoxicity of iproplatin and cisplatin in a human melanoma cell line SK-MEL-2. Depletion of GSH was dependent on the concentration and time of incubation with BSO. BSO (100 μM) depleted GSH by 85% at 24 h and by 91% at 48 h. BSO (10 to 100 μM) by itself was not cytotoxic to SK-MEL-2 cells. At 85% depletion of GSH, cytotoxicity of iproplatin was increased by a factor of >7 and that of cisplatin by <2. These results confirm the previous finding that GSH interferes with the cytotoxicity of iproplatin to a significantly greater extent than that of cisplatin. Equitoxic IC₆₅ and IC₉₀ values of cisplatin (2 μM and 5 μM) or iproplatin (25 μM and 50 μM) had no effect on the intracellular GSH levels in SK-MEL-2 cells. Also, depletion of GSH by BSO had no effect on the accumulation of platinum from either cisplatin or iproplatin in this cell line. Our results suggest that the effect of GSH on the cytotoxicity of cisplatin and iproplatin in this cell line was not a consequence either of differences in GSH–Pt conjugate formation, or of differences in platinum accumulation induced by GSH depletion. GSH may have modulated the cytotoxicity of these platinum complexes by other means such as effects on DNA repair, apoptosis, free radical scavenging or through other yet unidentified mechanisms. Received: 1 August 1995 / Accepted: 12 September 1996