Marshall P. Goren

Cumulative renal tubular damage associated with cisplatin nephrotoxicity.

SummaryWe assessed the acute and chronic effect of multiple courses of cisplatin therapy on renal tubules by monitoring the urinary excretion of alanine aminopeptidase, N-acetyl-β-D-glucosaminidase, and total protein. Urine specimens were obtained before and after doses of cisplatin (90 mg/m2) given to 12 patients. Each dose of cisplatin induced transient increases in enzyme excretion, followed by proteinuria 3–5 days later. Transient enzymuria after the last cisplatin dose was significantly greater than that after the first dose. Moreover, persistent increases in urinary N-acetyl-β-D-glucosaminidase and serum creatinine concentrations over pretherapy levels indicated chronic renal tubular damage. Our findings disclosed striking differences between patients in susceptibility to progressive nephrotoxicity.

Ifosfamide neurotoxicity is related to previous cisplatin treatment for pediatric solid tumors.

Neurotoxicity developed in 22 of 97 children and adolescents with malignant solid tumors treated within a phase II ifosfamide protocol. The occurrence of neurotoxicity was related to previous cumulative dosages of cisplatin. One third of the patients who had received more than 600 mg/m2 of cisplatin developed this complication. The relative risk increased 3.2-fold with previous cisplatin dosages above 301 to 600 mg/m2, and 4.1-fold with dosages of 601 to 1,340 mg/m2. The increased risk of neurotoxicity in patients who had received more than 600 mg/m2 of cisplatin may be related to either a decreased clearance of ifosfamide itself or of the drugs active metabolites.

A phase I-II trial of carboplatin and 5-fluorouracil combination chemotherapy in advanced carcinoma of the head and neck.

Twenty-nine patients with recurrent or advanced, incurable head and neck cancer were entered into a phase I-II trial of carboplatin in combination with 5-fluorouracil (5-FU), 1,000 mg/m2/d continuous intravenous (IV) infusion for five days every 28 days. The initial dose of carboplatin was 300 mg/m2 for patients with Karnofsky performance scores greater than or equal to 70%, and 240 mg/m2 for patients with scores of 50% to 60%. Subsequent doses were modified to achieve grade 2 myelo-suppression: WBC, 2,000 to 2,999 cells/microL; granulocytes, 1,000 to 1,499 cells/microL; and platelets, 50,000 to 75,000 cells/microL. Dose levels were 180, 240, 300, 360, and 420 mg/m2. Twenty-eight patients had squamous-cell cancers and one had an adenoid cystic carcinoma of the parotid. There were 26 patients with recurrent disease; 22 had received prior RT; only two had received other chemotherapy immediately before study entry. Three patients had newly diagnosed incurable stage IV disease. The median performance status was 80% (range, 60% to 90%). All patients had objectively measurable disease, and 28 were evaluable for response. There were three complete responses (CRs) and ten partial responses (PRs) (48% CR and PR); the median duration of response was 4.7 months (range, 1.5 to 15+ months). Dose-limiting toxicities were granulocytopenia, thrombocytopenia, and stomatitis. Prolonged myelosuppression delayed retreatment in eight patients and delayed 19 of 107 (18%) courses. Stomatitis occurred in 61% and diarrhea in 29%. 5-FU dosage was decreased in ten patients (36%) for grade 2 or greater stomatitis or diarrhea. Mild to moderate nausea and vomiting occurred in 66% of patient trials in which no pretreatment antiemetics were administered. Other toxicities included phlebitis from 5-FU in 71%, skin toxicity in 11%, mild alopecia in 25%, and fatigue in 54% of patients. Nephrotoxicity (creatinine greater than 2.0 mg/dL) occurred in one patient. The dose of carboplatin resulting in grade 2 toxicity was 180 mg/m2 in one patient, 240 mg/m2 in one, 300 mg/m2 in seven, 360 mg/m2 in ten, and 420 mg/m2 in one. Based on these results, we recommend a starting dose of carboplatin, 300 mg/m2, in combination with five days of continuous infusion 5-FU. In this dose and schedule, this combination was well tolerated and demonstrated antitumor activity in head and neck cancer. To confirm these promising results, a Southwest Oncology Group prospective randomized trial is in progress comparing carboplatin and 5-FU, cisplatin and 5-FU, and standard-dose weekly methotrexate in recurrent-disease patients.

Tubular nephrotoxicity during long-term ifosfamide and mesna therapy

SummaryThe nephrotoxic effects of ifosfamide were assessed in 18 children and adolescents given cumulative doses of 32–112 g/m2 (1.6 g/m2 per day in sequential 5-day courses) with the uroprotectant mesna (1.2 g/m2 per day). Tubular nephrotoxicity was evaluated by measuring the urinary concentrations ofN-acetyl-β-d-glucosaminidase (NAG), alanine aminopeptidase (AAP), and total protein before and during sequential courses of therapy. Of 15 patients who had normal levels of tubular markers before ifosfamide therapy, only 1 developed a persistent increase in baseline values of the three tubular markers with the sixth course of ifosfamide. Although transient increases in the excretion of these markers were observed during each 5-day course of ifosfamide, the magnitude did not increase over sequential courses in these 15 patients. Of the remaining three patients who had increased NAG levels before ifosfamide therapy, two showed a progressive increase in enzymuria and proteinuria, and serum creatinine concentrations increased in a single patient who had obstructive uropathy. Our data suggest that children with normal renal function can be given large cumulative amounts of ifosfamide in fractionated doses with little risk of progressive clinical nephrotoxicity.

Enhancement of methotrexate nephrotoxicity after cisplatin therapy

We measured urinary levels of total protein, N‐acetyl‐β‐D‐glucosaminidase (NAG), alanine aminopeptidase, and adenosine deaminase‐binding protein in ten children with osteogenic sarcoma who were receiving combination chemotherapy that included 12 doses of methotrexate (12 g/m2). Analysis of the changes in these sensitive markers of renal tubular damage permitted detection of subclinical methotrexate‐induced nephrotoxicity. In the absence of cisplatin, methotrexate therapy was associated with significant but transient increases in each of the four markers. Irreversible nephrotoxicity, indicated by persistent rises in NAG and alanine aminopeptidase as well as increased serum creatinine levels, was associated with doses of methotrexate that followed the administration of cisplatin (400 mg/m2). The biphasic pattern of total protein and NAG excretion observed in all patients suggests more than one mechanism of methotrexate‐induced nephrotoxicity. Monitoring renal tubular damage in patients who are receiving methotrexate in combined‐drug regimens would provide useful information for scheduling nephrotoxic drugs in clinical trials.

Carboplatin (CBDCA), iproplatin (CHIP), and high dose cisplatin in hypertonic saline evaluated for tubular nephrotoxicity

SummaryWe compared the acute tubular nephrotoxicity of three platinum compounds in children and adults with solid tumors by monitoring the urinary excretion of alanine aminopeptidase, N-acetyl-β-D-glucosaminidase, and total protein. Cisplatin (100 mg/m2) was administered with mannitol, or at a twofold larger total dosage (50 mg/m2 per day for 4 days) in a 3% saline infusion. Carboplatin (300 mg/m2) was administered in combination with 5-fluorouracil, and iproplatin was administered in dosages ranging from 216 to 388 mg/m2. Enzymuria and proteinuria induced by cisplatin at a total dosage of 200 mg/m2 on a divided schedule did not significantly differ from that observed for the single 100 mg/m2 dose. Enzymuria and proteinuria induced by carboplatin and iproplatin were significantly less than that for cisplatin; however, one patient developed chronic tubular damage after three courses of carboplatin, and the acute tubular toxicity of iproplatin in one of 15 patients was exceptional. Our findings support the value of administering cisplatin in hypertonic saline on a divided schedule as a strategy to reduce acute tubular damage. Although carboplatin and iproplatin are less nephrotoxic than cisplatin, occasionally patients experience subclinical acute or chronic tubular damage that may lead to overt nephrotoxicity with continued therapy.

Determination of urinary 2- and 3-dechloroethylated metabolites of ifosfamide by high-performance liquid chromatography.

In vivo oxidation of chloroethyl side-chains on ifosfamide produces the toxin chloroacetaldehyde. Production of this labile metabolite can be indirectly quantitated by monitoring the excretion of the residual 2- and 3-dechloroethylated ifosfamide. Urinary ifosfamide and the two dechloroethylated metabolites were extracted into chloroform from alkalinized salt-saturated urine, followed by high-performance liquid chromatographic separation using an acetonitrile gradient on a reversed-phase column and ultraviolet detection at 190 nm. In five patients given 1.6 g/m2 ifosfamide, 11-30% of the dose was excreted over 24 h as unchanged drug, 11-21% as 3-dechloroethylated and 3-10% as 2-dechloroethylated ifosfamide.

Increased tubular enzyme excretion in preeclampsia

The pathophysiology of preeclampsia includes ischemia and microinfarctions of the kidney, which could induce renal tubular cells to release enzymes into urine. We therefore measured the concentrations of two markers of renal tubular damage, N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase, in urine specimens from women with mild or severe preeclampsia and compared the results with those from healthy pregnant and nonpregnant women. The median urinary concentrations of N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase in women without preeclampsia increased progressively through the first, second, and third trimesters and reached maximum values of 1.12 and 0.77 U/mmol creatinine, respectively. Median concentrations of the two enzymes were significantly higher in women with mild preeclampsia (N-acetyl-beta-D-glucosaminidase = 1.40, alanine aminopeptidase = 1.12 U/mmol creatinine) or severe preeclampsia (N-acetyl-beta-D-glucosaminidase = 2.90, alanine aminopeptidase = 1.26 U/mmol creatinine). This increased enzyme excretion indicates subclinical preeclamptic renal tubular damage.

Combined intravenous and oral mesna in outpatients treated with ifosfamide

Purpose: To prevent hemorrhagic cystitis, mesna is typically injected intravenously (IV) at the time of an ifosfamide dose and 4 and 8 h later. To simplify outpatient ifosfamide therapy, we gave the second and third mesna doses orally. Methods: The mesna doses (400 or 600 mg/m2) were 40% (w/w) of each ifosfamide dose (1.0 or 1.5 g/m2), which was given daily for 5 days. We evaluated urinary mesna excretion and plasma concentrations in ten patients from the beginning of mesna infusion until the time of the second oral dose. The first oral dose was administered at hour 2 in the last six patients to allow time for absorption of mesna. Results: The rate and amount of mesna excretion was less variable over time and among patients after oral than after IV administration. No macrohematuria was observed in these ten patients nor in an additional 50 patients given oral mesna at hours 2 and 8 during at least two cycles of ifosfamide therapy. Conclusion: These pharmacokinetic and clinical efficacy data support the use of a combined regimen of IV and oral mesna to simplify outpatient ifosfamide administration.

Pharmacokinetics of an intravenous-oral versus intravenous-mesna regimen in lung cancer patients receiving ifosfamide.

PURPOSE To compare the pharmacokinetics of the approved I.V. (intravenous) mesna regimen and an investigational I.V.-oral regimen that could be used in outpatients who receive ifosfamide. PATIENTS AND METHODS The I.V. regimen consisted of three I.V. mesna doses given at 0, 4, and 8 hours after ifosfamide administration. The investigational regimen included an I.V. mesna dose given concurrently with ifosfamide, followed 2 and 8 hours later by oral administration of mesna tablets. I.V. and oral mesna doses equaled 20% and 40%, respectively, of the ifosfamide dose. The study subjects were 12 lung cancer patients who received ifosfamide 1.2 g/m2 daily for 5 days. The patients were randomized to receive either the I.V.-oral or I.V. mesna regimen on day 1, followed by crossover to the other regimen on days 2 through 5 of ifosfamide treatment. The urinary profiles of mesna and dimesna excretion were determined on days 1, 2, and 5; pharmacokinetic parameters for blood samples were determined only on day 5. RESULTS During the first 12 hours after ifosfamide administration, the amount of mesna excreted and the profile of urinary mesna excretion was similar for both regimens; however, the I.V.-oral regimen showed less fluctuation in the excretion rate and higher trough values. During hours 12 to 24, about eightfold more mesna was excreted by patients given the I.V.-oral than the I.V. regimen. CONCLUSION These pharmacokinetic data show that the I.V.-oral regimen should be at least as uroprotective as the I.V. mesna regimen. Patients may also benefit from the I.V.-oral regimen because of the higher trough values during hours 0 through 12 and the sustained urinary mesna excretion during hours 12 through 24.