Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tiazofurin, an investigational antimetabolite, is undergoing clinical evaluation in leukemia. We analyzed the data base of 198 patients entered in Phase I trials to characterize the incidence and severity of toxicities associated with tiazofurin according to dose and schedule. Severe myelosuppression occurred infrequently, and was not dose-dependent. A five day bolus schedule had a higher incidence of severe or life-threatening neutropenia than other schedules. Tiazofurin produced lymphopenia which was not dose-dependent in the range of 23-36% decrease from baseline, and the effect on lymphocyte count was generally greater than the decline in neutrophil count. Non-hematologic toxicity of a moderate or worse severity (greater than or equal to grade 2) included nausea and vomiting (18% of all courses), serum transaminase elevations (SGOT, 16%; SGPT, 9%), rash (9%), stomatitis (3%), conjunctivitis (3%), headache (10%), other signs of central nervous system toxicity (8%), and cardiac toxicity, primarily pleuropericarditis (4%). Dose-related cutaneous toxicity, headache, and nausea and vomiting were evident in the five day bolus schedule, and myalgia was more frequently reported at higher doses on the single dose schedule. The five day continuous infusion (CI) schedule had a higher incidence of neurotoxicity, cardiac toxicity, SGPT elevations and ocular toxicity than the daily for five days bolus schedule, but none of these differences attained statistical significance. Although the peak plasma concentrations of tiazofurin achieved with the five day bolus schedule were 3-fold higher than the steady-state plasma levels seen with an equal dose given by CI, the area under the concentration-time curve (AUC) was approximately 1.6-fold higher with CI. These observations suggest that both high peak plasma concentrations (above 400 microM) and prolonged exposure to plasma levels exceeding 50 microM may result in a higher incidence of serious non-hematologic toxicity.
 ...
PMID:Clinical toxicity associated with tiazofurin. 220 Jul 59

Tiazofurin (2-B-D-Ribofuranosylthiazole-4-Carboxamide: NSC 286193) is a nucleoside antimetabolite that acts as a potent inhibitor of IMP dehydrogenase resulting in a guanine nucleotide deprivation. Recent in vivo biochemical observations in rats bearing hepatoma suggested a correlation between depletion of guanine nucleotides and antitumor effect. The present phase I trial utilized a weekly x 3 bolus infusion schedule, repeated every 5 weeks. Biochemical measurements of GTP and dGTP were performed in patients at each dose level. Twelve patients received 16 courses of the drug in doses ranging from 1100 to 2050 mg/m2 weekly x 3. The dose limiting toxicities were pericarditis and clinical symptoms suggestive of a more generalized serositis (chest and abdominal pain). Other toxicities included reversible elevations in CPK (MM band only) and SGOT, nausea, vomiting, and arthralgias. Neurotoxic effects were generally mild, including headaches, anxiety, and malaise. Only 1 of 6 patients evaluated for tiazofurin's biochemical activity showed a sustained depletion of guanine nucleotide pools. No antitumor activity was observed. The maximally tolerated dose of tiazofurin on this intermittent weekly x 3 schedule was 1650 mg/m2. Toxicity and the overall lack of biochemical and biologic effect at clinically achievable doses may preclude further clinical evaluation of this drug on a weekly schedule. The toxicities observed in our study were similar to those reported for phase I investigations using a considerably higher dose intensity with daily x 5 schedules.
 ...
PMID:Phase I trial and biochemical evaluation of tiazofurin administered on a weekly schedule. 234 2

A phase I trial of 2-beta-D-ribofuranosylthiazole-4-carboxamide (NCS 286193, tiazofurin) was conducted using a 5-day i.v. bolus schedule, every 21 days. Thirty one patients with advanced cancer were entered on the trial. A total of 106 cycles were administered with doses ranging from 550 to 2750 mg/m2. Concomitant administration of Allopurinol was necessary to prevent hyperuricemia. Tiazofurin was difficult to evaluate and many side effects were variable and sporadic. The dose limiting toxicities were nonhematologic consisting particularly of myalgias, headaches and general malaise. Other toxicities included nausea, vomiting, stomatitis, lethargy, sleeping difficulty, sinus bradycardia, skin rash, desquamation of the palms and soles, photophobias and burning of the eyes. Hematologic toxicity was mild and not dose related though it led to a neutropenic septic death in one patient at 2750 mg/m2. Anemia was documented in 60% of cycles. Biochemical abnormalities consisted of mild hyperglycemia, hyperuricemia and elevated skeletal creatinine phosphokinase levels which did not correlate with the incidence or degree of myalgias. Though some patients were able to tolerate higher doses, the recommended dose for phase 2 study is 1650 mg/m2. Further studies will be required to achieve a better understanding of this interesting drug.
 ...
PMID:Phase I study of tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide, NSC 286193). 238 15

Tiazofurin is a novel C-nucleoside with significant antitumor activity in murine tumor models. In a phase I clinical trial, patients received tiazofurin by bolus iv infusion daily for 5 days. Six doses ranging from 550 to 4100 mg/m2/day were evaluated. Thirty-one treatment courses were initiated in 21 patients. Tiazofurin induced multiple, transient toxic effects at all but the lowest dose level, and treatment interruption was a common result. Nine of 28 treatment courses initiated at doses greater than or equal to 1100 mg/m2/day were interrupted at less than 5 days; only five of eight courses initiated at 1100 mg/m2/day were completed. Symptoms leading to treatment interruption included headache, nausea and emesis, and lethargy and malaise. Other significant, transient toxic effects included skeletal muscle injury manifest as pain, weakness, or serum biochemical abnormalities; mucocutaneous effects; and mental or mood changes. One case each of transient pericarditis and fatal cardiomyopathy occurred at the highest dose. Myelosuppression was observed but was transient and not dose limiting. In addition to leukopenia and thrombocytopenia, unexpected declines in serum hemoglobin were observed, although these were of uncertain significance. Tiazofurin induced significant increases in uric acid production which could be reversed with coadministration of allopurinol. Pharmacokinetic analysis revealed tiazofurin plasma elimination to be at least biphasic, with a beta-half-time of 4.2 hours; most of an injected dose could be recovered from the urine as unaltered compound within 24 hours. From this study we conclude that an appropriate dose for phase II trials with this schedule is less than or equal to 1000 mg/m2/day. The schedule may be a difficult one for clinical evaluation of antitumor activity, however, because of the possibility of frequent treatment interruption due to multiple systemic toxic effects.
 ...
PMID:Phase I trial of tiazofurin administered by i.v. bolus daily for 5 days, with pharmacokinetic evaluation. 380 11

Tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide, TCAR, Riboxamide, NSC 286193) is a novel C-nucleoside with antitumor activity against several murine tumor models, including Lewis lung carcinoma. The mechanism whereby this compound exerts its antineoplastic effects is most likely related to a state of guanine nucleotide depletion whereby the anabolite, thiazole-4-carboxamide adenine dinucleotide, potently inhibits inosine-5'-monophosphate dehydrogenase. This Phase I study was designed to determine the maximally tolerated dose of Tiazofurin administered on a 5-day, every-28-day schedule. Tiazofurin levels were measured using a high-pressure liquid chromatography assay, and pharmacokinetic studies were performed in patients treated at each dose level. Nineteen patients received a total of 24 courses of the drug in doses ranging from 550 to 2200 mg/sq m. The dose-limiting toxicities were pleuropericarditis and a general illness best described as a "viral-like" syndrome (manifested by severe malaise, headaches, myalgias, fever, nausea, vomiting, and diarrhea). Other toxicity included myelosuppression, hyperuricemia, elevated serum creatine phosphokinase and serum glutamic oxaloacetic transaminase, conjunctivitis, mucositis, and desquamation of the palms of the hands. Plasma clearance of Tiazofurin followed a biexponential pattern with a harmonic mean terminal half-life of 7.6 h. The mean volume of distribution at steady state was 30 liters/sq m, and the mean plasma clearance was 3 liters/h/sq m. The total cumulative urinary excretion ranged from 15 to 49%. The maximally tolerated dose of Tiazofurin on a 5-day schedule was 1650 mg/sq m. The recommended dose for Phase II evaluations is 1100 mg/sq m for 5 days. However, exploration of other schedules which might allow administration of more Tiazofurin combined with biochemical studies including thiazole-4-carboxamide adenine dinucleotide measurements would be desirable.
 ...
PMID:Phase I evaluation and pharmacokinetics of tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide, NSC 286193). 398 13

Tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide), a new nucleoside antimetabolite, was evaluated in a phase I trial involving children with refractory cancers. The drug was administered i.v. as a 10-min infusion daily for 5 consecutive days repeated at 3-week intervals. The dose ranged from 550 to 3300 mg/sq m/day. Seventeen patients received 23 courses and were evaluable for toxicity. The maximally tolerated dose was 2200 mg/sq m/day. The major dose-limiting toxicities were nonhematological. Neurotoxicity, including headache, drowsiness, and irritability, was common and was the principal dose-limiting toxicity at the higher doses. Severe myalgias were also dose limiting in one patient. Other side effects were mild, reversible elevations in serum transaminases; nausea, vomiting, and diarrhea; mild hypertension; dysphagia; and exfoliative dermatitis of the hands and feet. Myelotoxicity was not significant. The pharmacokinetics of tiazofurin was studied in 16 patients. Plasma disappearance was triphasic with half-lives of 9.7 min, 1.6 h, and 5.5 h. Clearance was dose related, ranging from 120 ml/min/sq m at 550 mg/sq m/day to 70 ml/min/sq m at 3300 mg/sq m/day. The primary route of elimination was renal with 85% of the drug recoverable in the urine as the parent compound in the 24 h following administration.
 ...
PMID:Pediatric phase I trial and pharmacokinetic study of tiazofurin (NSC 286193). 402 92

Benzamide riboside (BR), a synthetic C-nucleoside, acts as a strong growth inhibitor of cancer cells in vitro and in vivo. BR, like TR and related nucleoside prodrugs, act by anabolism to NAD analogs. These analogs selectively inhibit IMPDH, leading to depletion of cellular GTP, growth cessation, and cell differentiation. To date only preclinical studies have been carried out. However, in tiazofurin (TR), a related drug, phase I/II clinical trials have been conducted in patients with acute leukemia and shown to be a very promising agent with a response rate of 85% in 26 patients in one of the trials. Tiazofurin is now undergoing phase III clinical trials as a result. Dose limiting toxicity of tiazofurin was headache, somnolence and nausea with no myelosuppression noted. By contrast, BR showed skeletal muscle toxicity, hepatotoxicity and myelosuppression in preclinical data. Skeletal muscle toxicity was noted in the paraspinal muscles and may represent dose-limiting toxicity. Since BR does exhibit myelosuppression, the most common chemotherapy-related side effect in humans, careful judgment is warranted should BR be included in multidrug regimens, although BR's potent cytotoxicity to tumor cells in preclinical models still makes it a promising drug.
 ...
PMID:Toxicity and efficacy of benzamide riboside in cancer chemotherapy models. 1196 43