Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Little is known about the in vivo effects of inhibition of the mitochondrial pyrimidine de novo synthesis enzyme dihydroorotic acid dehydrogenase (DHO-DH). In mice a new inhibitor of DHO-DH, Brequinar sodium (DUP-785, NSC 368390) depleted the plasma uridine concentration to 40% within 2 h, followed by a small rebound after 7-9 days. The drug was subsequently evaluated in a Phase I clinical trial, during which it was possible to follow its biochemical effects in 24 patients (27 courses). In addition to the measurement of plasma uridine concentrations, we also measured in lymphocytes of 9 patients (10 courses) the duration of DHO-DH inhibition. Brequinar sodium was administered every 3 weeks as an i.v. infusion at dose levels of 15-2250 mg/m2. The biochemical effects were studied following the first administration of the drug. In sonicated extracts of lymphocytes from 7 healthy volunteers the activity of DHO-DH varied from 2.0 to 3.9 nmol/h per 10(6) cells, while in the lymphocytes of 9 patients obtained immediately before treatment this value was between 0.5 and 4.8 nmol/h per 10(6) cells. Within 15 min of drug administration DHO-DH activity was not detectable and was still low up to 1 week later. Duration of the inhibition appeared to be related to the extent of clinical toxicity, e.g., myelosuppression, nausea, vomiting, diarrhea, and mucositis. Severe lymphopenia was observed in patients receiving Brequinar sodium at the maximum tolerated dose. At dose levels of greater than or equal to 600 mg/m2, uridine depletion (40-85%) was observed between 6 h and 4 days, followed by a rebound of 160-350% after 4-7 days. The extent of the depletion and of the accompanying rebound of uridine levels and the extent and duration of DHO-DH inhibition in the individual patients could be partially associated with drug toxicity in these patients. This is the first report describing biological effects of DHO-DH inhibition in humans in relation to the degree and duration of inhibition of this enzyme.
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PMID:In vivo inhibition of the pyrimidine de novo enzyme dihydroorotic acid dehydrogenase by brequinar sodium (DUP-785; NSC 368390) in mice and patients. 216 43

Brequinar sodium is a quinoline carboxylic acid derivative that has shown antitumor activity in a number of in vivo murine and human tumor xenograft models. Its mechanism of action is blockade of de novo pyrimidine biosynthesis by inhibition of dihydroorotic acid dehydrogenase. In vitro and in vivo studies demonstrate the superiority of prolonged drug exposure in achieving tumor growth inhibition. This phase I study evaluated the administration of brequinar sodium by short, daily i.v. infusion for 5 days repeated every 4 weeks. Fifty-four subjects were enrolled in the study and received drug in doses ranging from 36-300 mg/m2. The dose-limiting toxicities were mucositis and diffuse skin rash. Other toxicities included myelosuppression, nausea, vomiting, malaise, and burning at the infusion site. The maximum tolerated dose on the "daily times 5" schedule was 300 mg/m2. The recommended phase II dose is 250 mg/m2. Pharmacokinetic analysis of the day 1 drug clearance curves in 51 subjects showed slight nonlinearity in the relationship between dose and area under the clearance curve (AUC). The dose versus AUC relationship was well described using a Michaelis-Menten model of brequinar elimination kinetics with Vmax = 45 (micrograms/ml)/h and Km = 123 micrograms. Analysis of the day 5 drug clearance curves revealed a diminution in Vmax to 30 (micrograms/ml)/h. As a consequence of the reduction in Vmax brequinar plasma concentrations on day 5 were higher than predicted from day 1 drug kinetics. Pharmacodynamic analysis of the day 1 kinetic parameters and the toxicities occurring during the first cycle of drug therapy revealed significant correlations between mucositis and dose, AUC, and peak brequinar concentration; between leukopenia and AUC and peak drug concentration; and between thrombocytopenia and beta elimination rate.
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PMID:Phase I and pharmacokinetic study of brequinar sodium (NSC 368390). 236 34

A phase I study of a new fluorinated pyrimidine compound, 5'-deoxy-5-fluorouridine (5'-DFUR), was performed in 37 patients with various malignant cancers. Starting dose was 600 mg/m2/day (900 mg/body/day) and escalated up to 3900 mg/body/day. The dose given was divided into 3 administrations a day for 5 consecutive days. Subjective symptoms were observed in cases given a dose of over 2,100 mg/body/day. Gastro-intestinal disturbances such as nausea, vomiting and anorexia were the major side effects. In the hematological and urinary examinations, no severe abnormal signs were observed. The maximum tolerated dose was considered to be 2.100 mg/body/day, and the dose-limiting factor was gastro-intestinal disturbance. 5-FU levels were determined in the serum and tumor tissues. 5'-DFUR was well absorbed. The 5-FU level in tumor tissue was very high at 2 to 3 hours post-dose and then rapidly decreased, being 0.05 microgram/g 12 hours after administration. The optimal dosage for a phase II study was suggested to be less than 2,100 mg/body/day.
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PMID:[Phase I study of 5'-deoxy-5-fluorouridine (5'-DFUR)]. 293 58

A phase II trial of 5'-deoxy-5-fluorouridine (5'-DFUR), a new fluorinated pyrimidine analog which has been demonstrated to have potential superiority over 5-FU and tegafur for chemotherapy of murine tumors, was performed in patients with advanced non-small cell carcinoma of the lung and metastatic pulmonary tumors. 5'-DFUR at a dose of 800 mg/m2 was given per os every day for more than four weeks. None of 15 evaluable patients with non-small cell carcinoma of the lung and 15 evaluable patients with metastatic pulmonary tumors showed a complete or partial response. Toxic effects of 5'-DFUR included anorexia (29%), diarrhea (26%), nausea (23%), vomiting (10%), leukocytopenia (10%), general fatigue (10%), liver disorder (6%) and thrombocytopenia (6%).
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PMID:Phase II study of oral administration of 5'-deoxy-5-fluorouridine (5'-DFUR) for solid tumors. 624 May 46

5-Fluorouracil (FUra) is a clinically useful antineoplastic agent. Preclinical studies suggest that the therapeutic effects of FUra can be enhanced by pretreatment with N-(phosphonacetyl)-L-aspartic acid (PALA), an inhibitor of aspartate transcarbamylase. The objective of treatment with PALA is to increase the activation of FUra by inhibiting the normal pathway of de novo pyrimidine biosynthesis. Theoretically, the optimal dose of PALA should produce effective blockade of this pathway without increasing toxic effects of FUra. Using pyrazofurin-induced orotic aciduria and orotidinuria as a measure of this pathway, it as determined that PALA (250 mg/sq m) is effective in inhibiting total-body pyrimidine synthesis. Sixty-eight adult patients with cancer were treated with combinations of PALA and FUra. High doses of PALA (1 to 2 g/sq m) prevented the use of full dosage of FUra; however, PALA (250 mg/sq m) can be administered 24 hr before FUra (750 mg/sq m) once weekly for at least 3 weeks. The toxicity observed using that combination of doses was mild to moderate myelosuppression, mucositis, diarrhea, nausea, and vomiting. Further clinical studies are warranted.
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PMID:Phase I and clinical pharmacological evaluation of biochemical modulation of 5-fluorouracil with N-(phosphonacetyl)-L-aspartic acid. 683 57

A phase I study of a new fluorinated pyrimidine, 1-hexylcarbamoyl-5-fluorouracil (HCFU), was performed by a multi-institutional clinical study group using a total of 111 patients with histologically proven malignancies. The characteristic toxic effects were a transient hot sensation and pollakiuria, which occurred 15-120 minutes after oral administration of the drug, continued for 30 minutes to 4 hours, and subsided spontaneously. Gastrointestinal disturbances such as nausea, vomiting, diarrhea, and anorexia, which are common with 5-FU administration, also occurred with HCFU but did so less frequently. The maximum tolerated dose for a single oral administration was estimated to be between 12 and 15 mg/kg and the optimal daily dose for continuous administration was considered to be between 9 and 18 mg/kg, with divided daily administration. Fifty-seven patients received 5-19 mg/kg/day of HCFU for > 4 weeks, including 31 patients with > 60 days' treatment. Cumulative doses were from 9.5 to 166.2 g, with a mean of 26.3 g. Hematopoietic toxicity was slight and hepatic toxicity was questionable. No renal or other cumulative toxicity was observed. In ten of the 57 patients, favorable clinical effects were seen: an active decrease in the size of the solid tumor (three patients), the disappearance of ascites (six), and the improvement of intestinal obstruction due to peritoneal carcinomatosis (one).
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PMID:Phase I study of a new antitumor drug, 1-hexylcarbamoyl-5-fluorouracil (HCFU), administered orally: an HCFU clinical study group report. 744 23

Fazarabine (Arabinofuranosyl-5-azacytosine) is a synthetic pyrimidine nucleoside which combines the arabinose sugar of cytosine arabinoside with the triazine base of 5-azacytidine. It has demonstrated activity against a variety of human solid tumor xenografts including colon, lung and breast cancers. Eighteen patients with refractory metastatic colon cancer were enrolled in a phase II trial of fazarabine. The drug was administered as a 72 hr continuous infusion every 3-4 weeks; the starting dose was 2 mg/m2/hr as established in a previous phase I study. The major toxicity was neutropenia, as predicted from the phase I study. The median time to nadir for cycle 1 was 20 days, with a median granulocyte count of 437/microliters (range 36-1600/microliters); recovery was within 2-4 days, with only one incidence of fever and neutropenia in 42 cycles. Especially noted for their absence were thrombocytopenia, nausea, vomiting and stomatitis. No objective clinical responses were seen; one patient had stabilization of rapidly growing liver metastases for a period of 7 months. In view of fazarabine's narrow range of toxicities, future dose intensification trials utilizing fazarabine in combination with hematopoietic growth factors are worthy of consideration.
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PMID:Phase II study of fazarabine (NSC 281272) in patients with metastatic colon cancer. 768 14

S-1, an antineoplastic formulation of a fluorinated pyrimidine derivative containing tegafur (FT), CDHP, and potassium oxonate (Oxo) in a molar ratio of 1:0.4:1, was recently developed by Taiho Pharmaceutical Co., Ltd., with the aim of prolonging the effective plasma concentration of 5-fluorouracil (5-FU) over that produced by FT alone and reducing its dose-limiting gastrointestinal toxicity. As a part of the S-1 toxicity study, the single-dose toxicity of S-1 as well as that of its components, CDHP and Oxo, was investigated in mice, rats, and dogs. The following results were obtained. 1. In mice and rats, excretion of diarrheal stools, salivation, and alopecia were observed after S-1 administration. In severe cases, the animals subsequently showed emaciation due to weight loss or suppressed weight gain, decreased spontaneous motor activity, an anemic appearance, bradypnea, prone position, and death. In the CDHP and Oxo treatment groups of rats, the only toxic signs were soft or diarrheal stools on the dosing day. 2. In dogs, vomiting and excretion of diarrheal, mucous, or soft stools was observed after S-1 administration. In the CDHP and Oxo treatment groups, excretion of soft and diarrheal stools and vomiting were observed relatively frequently from the dosing day until day 1. 3. In the pathological examination of the animals given S-1, mice and rats showed pulmonary congestion/edema, dark red discoloration of the mesenteric lymph nodes, atrophy of lymphatic tissues such as the thymus and lymph nodes, decreases of lymphocytes in the splenic white pulp and mesenteric lymph nodes, a decrease in bone marrow cells, congestion of the glandular stomach, and aggregates of bacteria in the lung, liver, or spleen. In dogs, abnormal changes were observed mainly in the lymphatic organs such as the thymus and lymph nodes. 4. The LD50 values of S-1 in terms of the amount FT they contained were estimated to be 549 mg/kg for mice(male), 441-551 mg/kg for rats (both sexes) and about 53 mg/kg for dogs (male). The LD50 values of CDHP and Oxo were 2000 mg/kg or higher for both rats (both sexes) and dogs (male). 5. Hematopoietic and lymphatic impairments, immunosuppression associated with respiratory were considered to be the cause of death from S-1. The toxicity of S-1 reflects the toxicity of 5-FU and was not found the different toxicity by the addition of CDHP and Oxo.
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PMID:[Oral single-dose toxicity study of a new antineoplastic agent S-1, and its components, CDHP, and Oxo]. 902 58

Pemetrexed (Alimta; Eli Lilly and Co, Indianapolis, IN) is a multitargeted antifolate that inhibits several folate-dependent enzymes that play roles in purine and pyrimidine synthesis. The principal toxicities of pemetrexed are neutropenia, diarrhea, nausea/vomiting, mucositis, and skin rash. These toxicities are more frequent in vitamin-deficient (folate and vitamin B 12 ) patients, and can be ameliorated by the co-administration of folate and vitamin B 12 . The use of prophylactic dexamethasone is also recommended to reduce the frequency of severe skin rash. Pemetrexed has significant single-agent activity in previously treated and untreated patients with non-small cell lung cancer (NSCLC). A recent phase III trial comparing pemetrexed with docetaxel in previously treated NSCLC patients showed equivalent efficacy with less bone marrow toxicity (eg, neutropenia) in the pemetrexed group. These results were pivotal in the approval of pemetrexed for the treatment of refractory NSCLC. Pemetrexed has been combined with the platinums (ie, cisplatin, carboplatin, and oxaliplatin) in NSCLC to yield clinical activity similar to that of other platinum-based doublets. A comparative phase III trial of cisplatin/pemetrexed against cisplatin/gemcitabine (Gemzar; Eli Lilly and Co) is under way. Pemetrexed has also been evaluated in combination with gemcitabine, and although the optimal dose and schedule of this combination has not been defined, clinical activity similar to other nonplatinum-based doublets has been observed. Preliminary evidence suggests that pemetrexed can be combined with thoracic radiation therapy, but more data are needed to evaluate the potential advantage(s) pemetrexed may have in this setting. Pemetrexed/platinum doublets also appear to possess activity in extensive stage small cell lung cancer. A phase II trial of single-agent pemetrexed is under way in both sensitive- and refractory-relapsed small cell lung cancer. Given the activity and excellent tolerability of pemetrexed, further studies in lung cancer are warranted.
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PMID:The evolving role of pemetrexed (Alimta) in lung cancer. 1581 33

4-(Phenylamino)-5-phenyl-7-(5-deoxy-beta-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine 1 and related compounds known as "diaryltubercidin" analogues are potent inhibitors of adenosine kinase (AK) and are orally active in animal models of pain such as the rat formalin paw model (GP3269 ED50= 6.4 mg/kg). However, the utility of this compound class is limited by poor water solubility that can be attributed to the high energy of crystallization caused by stacking of the parallel C4 and C5 aryl rings in the solid state (compound 1 and GP3269 each with pH 7.4 solubility <0.05 microg/mL). To increase water solubility, the hydrophobic C4-phenylamino substituent was replaced with a more hydrophilic group, glycinamide. This modification resulted in improved water solubility while retaining AK inhibition potency. Analogues were studied where changes in the glycinamide moiety were combined with changes to the base and sugar. A lead compound, 4-N-(N-cyclopropylcarbamoylmethyl)amino-5-phenyl-7-(5-deoxy-beta-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine (16c) (IC50= 3 nM and water solubility = 32 +/- 9 microg/mL at pH 7.4), was further characterized in biological assays. Compound 16c exhibited strong oral efficacy in the rat formalin paw model (ED50 of 2.5 mg/kg). In the most advanced assay, 16c was found to inhibit bradykinin-induced licking in marmoset monkeys with an ED50 estimated at 0.9 mg/kg without producing evidence of side effects such as ataxia, sedation, and emesis at this dose. However, lethal toxicity in the rat formalin paw model occurred with high doses of 16c, and further work on this series was discontinued.
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PMID:Adenosine kinase inhibitors. 6. Synthesis, water solubility, and antinociceptive activity of 5-phenyl-7-(5-deoxy-beta-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidines substituted at C4 with glycinamides and related compounds. 1630 20


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