Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0854467 (myelosuppression)
 5,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Structure-activity studies of nitrosourea pharmacology have resulted in the synthesis of a new water-soluble agent,chlorozotocin, which has significant antitumor activity against the L1210 leukemia system and produces only a minor degree of inhibition of mouse and human bone marrow DNA synthesis compared to BCNU. It is important to emphasize that the bone marrow sparing feature of chlorozotocin is relative and that if the drug is administered at lethal dose levels in mice, myelosuppression is observed. The potential importance of these studies is the identification of a new and active nitrosourea antiumor agent with modified bone marrow toxicity. If aminoglucose modification of nitrosourea bone marrow toxicity can be confirmed in man without significant loss of antitumor activity, the use of such a compound could facilitate treatment of patients with neoplastic disease who have pre-existing abnormal bone marrow function. It would also allow the more effective use of a nitrosourea agent in combination with anticancer agents possessing more potent myelosuppressive properties.
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PMID:Pharmacology of chlorozotocin Nsc-178248), a new nitrosourea antitumor agent. 13 56

1-(2-Chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea (GANU), a water-soluble nitrosourea, differs from 2-[3-(2-chloroethyl)-3-nitrosoureido]-D-glucopyranose (chlorozotocin) by the placement of the cytotoxic group on C-1 of glucose. Its biological and biochemical properties are compared with those of chlorozotocin. At a 10% lethal dose (10 mg/kg i.p.), GANU demonstrates minimal myelosuppression. This dose failed to depress normal bone marrow DNA synthesis, in contrast to a 96% inhibition in L1210 DNA synthesis. In L1210 cell suspension, equimolar doses of GANU and chlorozotocin produced equivalent degrees of inhibition in DNA synthesis. GANU has significant L1210 activity in BALB/c X DBA/2 F1 mice treated on Day 2 of tumor growth. A 117% increased life-span and 15% 45-day survivors are atained with 15 mg/kg i.p., a 50% lethal dose. However, in concurrent studies using randomly selected littermate groups of mice, GANU proved less active than chlorozotocin which produced a 306% increased life-span (15 mg/kg i.p.). GANU and chlorozotocin have similar in vitro alkylating activity but the in vitro carbamoylating activity of GANU is sevenfold that of chlorozotocin. On a molar basis, the lethal toxicity of GANU is twice that of chlorozotocin. The significant carbamoylating activity of GANU may contribute to its greater toxicity and therefore limit the mumoles of alkylating agent that can be administered to the tumor. These structure-activity studies further confirm that the addition of a glucose carrier to a cytotoxic nitrosourea moiety can selectively reduce bone marrow toxicity while retaining antitumor activity.
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PMID:Biological and biochemical properties of 1-(2-chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea (NSC D 254157), a nitrosourea with reduced bone marrow toxicity. 13 78

Methanesulfonamide, N-[4-(9-acridinylamino)-30methoxyphenyl]-(NSC-249992), an acridine derivative with significant antitumor activity in animal tumor systems, was administered to 29 patients in a phase I clinical trial. The dose ranged from 10 to 160 mg/m2 with a single dose given every 28 days. The toxic effects included moderate to severe leukopenia and mild thrombocytopenia. Myelosuppression was more severe in patients with prior whole abdominal or pelvic radiotherapy. Superficial phlebitis occurred when the drug was diluted in a volume of less than 500 ml of 5% dextrose in water. Antitumor activity was detected in one patient with ovarian carcinoma. Phase II studies are indicated with this compound since it has reproducible and reversible toxicity with some evidence of antitumor activity. The starting dose of the drug for phase II trials should be 120 mg/m2 as a single iv dose repeated at 4-week intervals.
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PMID:Phase I study of methanesulfonamide, N-[4-(9-acridinylamino)-3-methoxyphenyl]-(m-AMSA) using a single-dose schedule. 36 Dec 22

Topotecan (SK&F 104864) is a novel antitumor agent whose mechanism of action is inhibition of the DNA unwinding protein topoisomerase I. An analog of camptothecin, topotecan was designed to be more water soluble in an effort to decrease the severe and sporadic toxicities experienced during phase I/II trials of the parent compound. In this phase I clinical and pharmacological trial, topotecan was given as a bolus intravenous (i.v.) infusion over 30 min every 21 days. A total of 42 patients entered the study, receiving doses ranging from 2.5 to 22.5 mg/m2. The maximum tolerated dose (MTD) of topotecan given in this schedule was 22.5 mg/m2. Myelosuppression, primarily neutropenia, was dose-limiting. The extent of prior therapy did not predict for more severe neutropenia. Non-hematologic toxicities were mild and included low-grade to moderate fever, nausea, vomiting, alopecia, diarrhea and skin rashes. There were no objective partial or complete responses, although there was a suggestion of antitumor activity in three patients. Topotecan undergoes pH-dependent hydrolysis of the lactone ring; only the closed, lactone form is active. The lactone form predominated during infusion, with hydrolysis occurring rapidly following the end of infusion. There were linear relationships between dose administered and peak plasma lactone concentrations as well as AUC lactone to AUC total. The lactone was rapidly cleared from plasma with a total body clearance of 25.7 (+/- 6.7) l/h/m2. The plasma lactone concentration declined rapidly with a harmonic mean terminal half-life of 3.4 (+/- 1.1)h. Lactone hydrolysis and renal excretion were the major routes of elimination.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A phase I clinical and pharmacokinetic study of the topoisomerase I inhibitor topotecan (SK&F 104864) given as an intravenous bolus every 21 days. 133 81

The recently synthesized nitrosourea, N-[N'-chloro-2-ethyl-N'-nitrosocarbamoyl]-S-methyl cysteamine sulfoxide (Perrimustine), is water soluble and has a high alkylating activity, similar to that of the widely used nitrsoureas BCNU and CCNU, and a low carbamoylating activity. Preclinical studies with a broad spectrum of murine tumors indicate that this new compound may be clinically useful. The maximally efficient dose range (MEDR) in L1210 bearing mice was 45 mg/m2 (subcurative dose) to 67 mg/m2 (subtoxic dose). The present phase I trial used an intrapatient escalation schedule, so that each patient entering the study received a potentially active dose. The first dose injected was 1:100 of the MEDR suboptimal dose to check for anaphylactic sensitivity. Patients were then given increasing doses at increasing time intervals until toxicity was observed. The highest dose was given on day 150-230. The main toxic effect was myelosuppression [five out of the 24 patients evaluated: one grade 4 thrombocytopenia, two grade 3 thrombocytopenia; anemia and leucopenia were milder (grade 1 to 2 on OMS scale)]. Of the 19 patients evaluated for clinical response, one showed response after the 45 mg/m2 dose (disappearance of the cerebral metastasis with persistence of hepatic localizations in a patient with melanoma) and the disease was stabilized in two cases (a pleural mesothelioma and a renal carcinoma with lung metastases) after 26 and 37 weeks, with total cumulative doses per m2 of 232 and 196 mg, respectively.
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PMID:Phase I trial of Perrimustine, a new cysteamine (2-chloroethyl) nitrosourea: an intrapatient escalation scheme. 152 2

Because the initial evaluation of N,N',N''-triethylenethiophosphoramide (thioTEPA) preceded the standardized approach to the Phase I trials, uncertainty surrounds the recommended dose. Since it has recently been demonstrated that an almost 100-fold increase in dose can be administered in bone marrow transplant regimens, we conducted a Phase I reevaluation of thioTEPA. ThioTEPA was administered i.v. in 50 ml 5% dextrose in water over 10 min. Twenty-seven patients were entered at doses ranging from 30 to 75 mg/m2. The major toxic effect was myelosuppression; thrombocytopenia greater than or equal to grade 3 occurred in four of seven patients, and leukopenia greater than or equal to grade 3 in two of seven patients at 75 mg/m2. Among eight patients at 65 mg/m2 only two had greater than or equal to grade 3 myelosuppression making this the recommended new phase II dose for the majority of patients. Moderate (grade 2) easily controlled nausea and vomiting was the only other major side effect. There was no alopecia or mucosal or neurological toxicity. Three partial remissions were observed among nine previously treated ovarian cancer patients. Plasma concentrations of thioTEPA and its major active metabolite triethylenephosphoramide (TEPA) were measured by gas chromatography. The half-life of thioTEPA ranged from 51.6 to 211.8 min, and its pharmacokinetics was dose dependent; total body thioTEPA clearance decreased with increasing dose. The half-life of TEPA was considerably longer than that of the parent compound (3.0 to 21.1 h); as a result, the area under the plasma concentration-time curve (AUC) of TEPA was severalfold greater than that of the parent compound. The ratio of TEPA AUC to thioTEPA AUC decreased with increasing dose, suggesting that formation of TEPA is a saturable step in elimination. The AUC and total body clearance of thioTEPA, but not of TEPA, were closely correlated with neutrophil but not platelet toxicity.
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PMID:Phase I/pharmacokinetic reevaluation of thioTEPA. 171 Jan 67

Intravesical chemotherapy has been shown to be of value in the treatment of superficial transitional cell carcinoma of the bladder, not only in the prevention of recurrence but possibly progression of the disease to higher stage as well. At the Department of Surgery, National University of Singapore from 1980 to 1986 we had used intravesical chemotherapy for multiple or recurrent superficial carcinoma of bladder in 45 patients. Of these, 21 patients had associated carcinoma in situ. Initially, thiotepa was used as the main intravesical chemotherapeutic agent. Since 1984, mitomycin C was introduced. The schedule used is 30 mg in 30 mg of water, and left in the bladder for 2 hours weekly for 4 weeks. Intermittent courses were given when deemed necessary on follow-up cystoscopy at 3 to 6 months. Patients were deemed to have good response if there was no evidence of tumour on cytology and biopsy at follow-up cystoscopy. Eleven patients had thiotepa only, of these 4 had good response, 4 were stable and 3 had progression of disease to higher stage. Thirty-four patients had mitomycin therapy. Thirteen of them following thiotepa treatment. Twenty-one patients (64%) had good response to therapy. Three patients (9%) had progression of disease, requiring cystectomy. Of those who responded to therapy, none had developed muscle invasive disease so far with mean follow-up of 43 months. Of the group of patients treated with mitomycin, no patient developed myelosuppression.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Intravesical chemotherapy for superficial carcinoma of the bladder. 178

Intravesical mitomycin C (MMC) therapy is used to treat superficial bladder cancer. This study was to establish the intra- and intersubject variabilities in the systemic (plasma) and target site (bladder) exposure to the drug and to identify the factors which contribute to these variabilities. The pharmacokinetics of MMC were studied in 10 patients. Treatment consisted of transurethral tumor resection followed by six weekly intravesical treatments with MMC (20 mg in 40 ml of water). The dosing solution was maintained in the bladder for 2 h. Pharmacokinetic studies were performed at the time of the first, fourth, and sixth or first, second, and fourth treatments with MMC for a total of 28 treatments. Concentration-time profiles of the plasma and bladder contents (i.e., urine), urine volumes, and urine pH were determined during and for up to 4 h after intravesical administration. Maximal plasma MMC concentrations averaged 43 ng/ml (range, 2.1-180.5 ng/ml) in treatment 1. In comparison, the MMC plasma concentration for myelosuppression reported in the literature is 400 ng/ml. Maximal plasma concentrations in treatments 2, 4, and 6 were at least 4-fold lower than those in treatment 1 and in most cases were below the detection limit of 0.5 ng/ml. This indicates that the absorption of MMC during the later treatments was less than in the first treatment given shortly after surgery. Urinary MMC concentrations during instillation declined from 519.4 +/- 34.8 micrograms/ml (mean +/- SD) in the dosing solution to 64.6 +/- 39.4 micrograms/ml 2 h after instillation. Thus, the superficial bladder tissue was exposed to drug concentrations 300- to greater than 34,000-fold higher than the plasma-perfused systemic tissues. Intravesical exposure to MMC, as determined by the area under the urine concentration-time curve, showed large intra- and intersubject variabilities (range, 2,185-40,411 micrograms-min/ml). Pharmacokinetic analysis showed that the bladder exposure to MMC inversely correlated with the residual urine volume at the time of drug administration (P less than 0.001), the urine production rate (P = 0.05), and the rate of drug removal by degradation and absorption during therapy (P less than 0.01). At the end of the 2-h treatment, recovery of MMC from the bladder instillate ranged from 1 to 100% and correlated with the urine pH at the time of removal (P less than 0.001). At pH between 5 and 5.5, less than 30% of the dose was recovered.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Pharmacokinetics of intravesical mitomycin C in superficial bladder cancer patients. 191 40

Melphalan-induced toxicity in nude mice following pretreatment with a regimen of L-buthionine sulfoximine (BSO), previously shown to enhance the activity of this alkylating agent against rhabdomyosarcoma and glioma xenografts, was examined. Mice were pretreated with i.p. BSO (2.5 mmol/kg x 7 doses at 12-h intervals plus concomitant availability of a 20-mM solution in the drinking water) or vehicle prior to a single i.p. injection of melphalan (35.65 mg/m2). As compared with control animals who received no BSO pretreatment, mice pretreated with BSO lost weight prior to therapy with melphalan (6.9% weight loss vs 0.3% weight gain; P less than 0.005) and showed a greater mean nadir weight loss after melphalan (3.8% vs. 2.1%; P = 0.049). Treatment with melphalan was associated with histologic evidence of reversible gastrointestinal toxicity, reversible myelosuppression, and histologic evidence of acute renal tubular necrosis, with no differences being observed between mice that had been pretreated with BSO and those that had been pretreated with vehicle. No evidence of cardiac, hepatic, or skeletal muscle toxicity was found in melphalan-treated animals. These results suggest that treatment of nude mice with melphalan following BSO-mediated depletion of glutathione does not result in enhanced organ toxicity despite an increase in the antineoplastic activity of this alkylating agent.
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PMID:Melphalan-induced toxicity in nude mice following pretreatment with buthionine sulfoximine. 204 29

A high dose of cytosine arabinoside (ara-C) was given to 51 patients during consolidation therapy or with refractory or relapsed acute leukemia. Ara-C was administered as a 3-hour infusion at a dose ranging from 2 to 3 g/m2 every 12 hours, diluted in 500 ml of 5% dextrose in water for 2 to 6 days. Complete remission was attained in 3 (25%) of 12 evaluable patients. Two with blast crisis of chronic myelogenous leukemia of these did not obtain complete remission. Death due to marrow aplasia occurred in five patients, and two of these had relatively good performance status and were given a dose of 3.0 g/m2 x 8 or 12 of ara-C. At a dose of 3.0 g/m2 x 6, the mean duration of granulocytes of less than 100/mm3 was 6.7 days. This duration seemed to be manageable myelosuppression. Therefore, 3.0 g/m2 x 6 was thought to be an adequate dose. Seizure occurred in one patient, and conjunctivitis was seen in another. In conclusion, from the manageable myelosuppression observed, administration of 3.0 g/m2 x 6 of ara-C seemed to be an adequate dose.
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PMID:[High-dose cytosine arabinoside treatment of leukemia with special reference to the optimal number of doses]. 277 89


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