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PubMed1995

A randomized trial comparing misoprostol three and seven days after methotrexate for early abortion.

OBJECTIVE: Our purpose was to determine whether vaginal misoprostol 7 days rather than 3 days after methotrexate injection increases the percent of successful abortions on the day of misoprostol administration. STUDY DESIGN: A randomized controlled trial was performed in women requesting an abortion at < or = 56 days' gestation. Eighty-six women were treated with methotrexate 50 mg/m2 intramuscularly followed 3 days (group 1) or 7 days (group 2) later by vaginal misoprostol 800 micrograms. The misoprostol dose was repeated if the abortion did not occur. RESULTS: Complete abortion occurred in 38 of 46 (83%) patients in group 1 and 39 of 40 (98%) in group 2 (p = 0.033). Of the women with complete abortions, 30 of 46 (65%) in group 1 and 27 of 40 (68%) in group 2 aborted the same day as the first or second dose of misoprostol (p = 0.823). Vaginal bleeding lasted 14 +/- 5 (mean +/- SD) days in group 1 and 17 +/- 9 days in group 2. The remaining women aborted after a delay of 24 +/- 6 days in group 1 and 28 +/- 13 days in group 2. For these women vaginal bleeding lasted 18 +/- 17 and 14 +/- 7 days, respectively, and the human chorionic gonadotropin-beta level was < or = 25 IU/L by 22 +/- 7 days after the abortion in group 1 and 19 +/- 9 days in group 2. Treatment failures in group 1 were four continuing pregnancies (9%), two incomplete abortions (4%), and two women who requested surgical termination after receiving both medications (4%). The treatment failure in group 2 was an incomplete abortion. Methotrexate and misoprostol side effects were infrequent. CONCLUSIONS: Methotrexate and vaginal misoprostol are more effective abortifacients when the misoprostol is given 7 days rather than 3 days after methotrexate. This treatment regimen may offer an alternative to surgical abortion or the use of antiprogestins and prostaglandin for medical abortion.

Abortifacient Agents, Nonsteroidal↗
PubMed1975

High dose methotrexate as a preoperative adjuvant in the treatment of epidermoid carcinoma of the head and neck. A feasibility study and clinical trial.

Thirty patients with operable epidermoid carcinoma of the head and neck were treated with intravenous high dose methotrexate and leucovorin rescue prior to resection. Their clinical courses were compared with those of thirty randomly selected patients matched for tumors site and clinical stage who were treated by surgery alone. No medical or surgical complications associated with methotrexate were encountered. An objective decrease in tumor size (primary lesion or nodal metastases) was noted prior to resection in twenty-three patients (77 per cent). The number of recurrences in the two groups was similar. However, these was a significantly greater disease-free interval in the methotrexate-treated patients (p less than 0.05). No significant differences in survival have been noted to date between the two groups. In view of the absence of complications, the regressions in tumor size, and the increase in postoperative disease-free interval in this trial, evaluation as preoperative adjuvants of higher doses of methotrexate and of other chemotherapeutic agents in combination with methotrexate appears warranted.

Carcinoma, Squamous Cell↗
PubMed1984

Hormonal alteration of methotrexate and folate polyglutamate formation in cultured hepatoma cells.

Glutamylation of the antifolate methotrexate in H35 hepatoma cells was stimulated by physiologic concentrations of insulin and dexamethasone. At saturating concentrations of the hormone a 2.7-fold stimulation could be obtained with insulin (65 nM, 16-h exposure) and a 1.8-fold stimulation with dexamethasone (100 nM, 16-h exposure). The increases in glutamylation caused by the hormones were not additive, and both were inhibited by actinomycin D and cycloheximide. N6,O2'-dibutyryl cAMP and theophylline caused a modest reduction of glutamylation in control and dexamethasone-treated cultures, but repressed the stimulation caused by insulin by approximately one-third. Enhancement of synthesis by dexamethasone and insulin was associated with increases in the tri-, tetra-, and pentaglutamate derivatives of methotrexate, with little change in intracellular methotrexate and methotrexate diglutamate. When the conversion of folinic acid into the folylpolyglutamate pool was examined in folate-depleted H35 cells, insulin and dexamethasone had similar effects. The results suggest that these hormones play a role in the glutamylation of the folate coenzymes in a liver-derived transformed cell line in culture and that these effects are also reflected in the interaction of the cells with antifolates such as methotrexate.

Animals↗
PubMed1993

Altered expression of unidirectional extrusion routes for methotrexate and cholate in an efflux variant of L1210 cells.

The specificity and function of two unidirectional anion-efflux pumps in mouse L1210 cells were evaluated using a variant cell line selected for growth in the presence of cholate and bromosulfophthalein. Transport analysis revealed that cholate efflux in the variant L1210/C7 cell line had declined 8-fold, due to the loss of a bromosulfophthalein-sensitive efflux system, the major extrusion route for cholate in parental cells. Efflux measurements showed further that a bromosulfophthalein-sensitive efflux system for methotrexate was also absent in L1210/C7 cells. Total unidirectional efflux of methotrexate, however, was similar in the variant and parental cells, since the loss in the bromosulfophthalein-sensitive system was compensated by a rise in a second probenecid-sensitive route. The latter was identified from inhibitor studies to be the same system which acts as a minor efflux route for methotrexate in parental cells. These results support the hypothesis that L1210 cells contain a bromosulfophthalein-sensitive efflux system which mediates the unidirectional extrusion of either methotrexate or cholate, and a second probenecid-sensitive route which differs from the bromosulfophthalein-sensitive system in inhibitor specificity and also in its ability to transport methotrexate but not cholate.

Animals↗
PubMed1986

Folylpolyglutamate synthetase inhibition and cytotoxic effects of methotrexate analogs containing 2,omega-diaminoalkanoic acids.

The properties of a series of methotrexate analogs containing 2,omega-diaminoalkanoic acids have been investigated. The compounds were potent inhibitors of dihydrofolate reductase but, unlike methotrexate, they were also inhibitors of mammalian folylpolyglutamate synthetases. The potency of synthetase and reductase inhibition increased with increasing length of the 2,omega-diaminoalkanoate moiety. The most cytotoxic compound and the most potent inhibitor of both dihydrofolate reductase (I50 = 2.5 to 4 nM) and folylpolyglutamate synthetase (Ki ca. 4 microM) contained 2,5-diaminopentanoic acid (ornithine). These compounds were 70- to 100-fold less cytotoxic than methotrexate to human leukemia cell lines; however, they retained their potency against sublines resistant to methotrexate via defective transport. Their dual loci of enzyme inhibition and their efficacy against methotrexate transport-defective cell lines indicate that these compounds may be an important new class of antifol.

Aldehyde Oxidase↗
PubMed1977

A rapid, sensitive and specific radioimmunoassay for methotrexate.

A rapid, sensitive, radioimmunoassay for methotrexate has been developed using tritiated methotrexate and an antiserum raised in rabbits against the immunogen, bovine serum albumin containing 34 methotrexate residues per protein molecule. Separation of bound and free drug was attained using donkey anti-rabbit precipitating serum. The method can accurately measure as little as 50 fmol methotrexate in capillary blood samples and is not interfered with by vast excesses of natural folates nor citrovorum rescue factor. The method can handle 30 samples per day with the results available after 6 h. This makes it suitable for monitoring serum methotrexate levels after high dose therapy when a result is required within 24 h to provide helpful information regarding impending toxicity and the need for extended citrovorum rescue factor or maintenance of urinary pH.

Cross Reactions↗
PubMed1993

Methotrexate for abortion at < or = 42 days gestation.

Methotrexate is cytotoxic to trophoblast and, in low doses, has minimal side effects. It is used to treat gestational trophoblastic neoplasia and ectopic pregnancy and has recently been shown to have similar effects on intrauterine trophoblast. A prior study suggested that methotrexate may successfully cause abortion of an early pregnancy without prostaglandin. To test this hypothesis, ten pregnant women at < or = 42 days gestation were treated with methotrexate 50 mg/m2 intramuscularly. Vaginal bleeding started 24 +/- 10 (mean +/- standard deviation) days after the injection and lasted 10 +/- 3 days. Methotrexate side effects occurred in 4 patients and were limited to the first 4 days after the injection. Methotrexate alone appears sufficient to abort a very early intrauterine pregnancy.

Abortifacient Agents, Nonsteroidal↗
PubMed1991

Methotrexate binds in a non-productive orientation to human dihydrofolate reductase in solution, based on NMR spectroscopy.

Dihydrofolate reductase (DHFR) is an intracellular target enzyme for folate antagonist drugs, including methotrexate. In order to compare the binding of methotrexate to human DHFR in solution with that observed in the crystalline state, NMR spectroscopy has been used to determine the conformation of the drug bound to human DHFR in solution. In agreement with what has been observed in the crystalline state, NOE's identified protein and methotrexate protons indicate that methotrexate binds in a non-productive orientation. In contrast to what has been reported for E. coli DHFR in solution, only one bound conformation of methotrexate is observed.

Binding Sites↗
PubMed1994

Interstitial pneumonitis after low-dose methotrexate therapy in primary biliary cirrhosis.

Interstitial pneumonitis is an uncommon complication of low-dose methotrexate therapy in patients with psoriasis but occurs in 3%-5% of patients with rheumatoid arthritis. We found a higher incidence of interstitial pneumonitis in patients with primary biliary cirrhosis (14%) and describe its clinical manifestations, treatment, and possible etiology. Blood tests, arterial blood gas determinations, chest radiographs, bronchoscopy, tear production, autoantibody tests, and serum immunoglobulin levels were obtained in six women who developed interstitial pneumonitis while receiving methotrexate in a double-blind prospective trial of methotrexate vs. colchicine in 87 patients with primary biliary cirrhosis. Six of 43 patients (14%) who received methotrexate compared with no patients receiving colchicine developed interstitial pneumonitis 19-61 weeks after starting treatment. The pneumonitis was characterized by dyspnea, hypoxemia, and bilateral lung infiltrates, all of which responded within 24 hours to the administration of intravenous glucocorticoids. There was no correlation between the pneumonitis and pre-existing lung disease, the severity of the primary biliary cirrhosis, the titer of antimitochondrial antibody, or other diseases associated with primary biliary cirrhosis. Patients with primary biliary cirrhosis receiving low-dose methotrexate (15 mg/wk) are more susceptible to interstitial pneumonitis than patients with psoriasis or rheumatoid arthritis. The pneumonitis appears to be a hypersensitivity reaction and responds rapidly to intravenous glucocorticoid therapy.

Aged↗
PubMed1996

Treatment of cervical pregnancy with methotrexate.

OBJECTIVES: To review our experience with early ultrasonographic diagnosis and fertility-preserving complete medical treatment of cervical pregnancy. METHODS: From January 1989 to December 1994, 11 cases of cervical pregnancy diagnosed by ultrasonography and treated with methotrexate were evaluated. Patients were treated as follows: systemic administration of methotrexate with leucovorin rescue, a single dose of 50 mg of methotrexate intramuscular injection, or transvaginal ultrasonographically-guided intra-amniotic instillation of 50 mg of methotrexate. RESULTS: The mean age of these patients was 33.3 +/- 6.2 years and gestational age at diagnosis ranged from 32 to 73 days. The maximal serum beta-hCG measured was 135,000 mIU/ml, and the time required for return to normal levels ranged from 20 to 157 days. The ectopic gestation was successfully ablated in all cases, and none required hysterectomy. CONCLUSION: If a cervical pregnancy is present and diagnosed early, methotrexate treatment, administered either systemically or locally, is effective as the definitive therapy.

Adult↗
PubMed1982

Methotrexate stimulation of asparagine synthetase activity in rat liver.

Methotrexate was found to stimulate asparagine synthetase activity in vivo by approximately six-fold in rat liver. The maximum effect of methotrexate on hepatic asparagine synthetase activity was observed sixteen hours after intraperitoneal injection of the drug. Cycloheximide, like methotrexate, is a protein synthesis inhibitor and was used to determine that asparagine synthetase activity was not preferentially stimulated under stress. As expected, hepatic asparagine synthetase activity falls markedly with the decreased protein synthesis caused by injection of cycloheximide. It is proposed that methotrexate inhibits serine-dependent glycine biosyn-thesis by decreasing the concentration of tetrahydrofolate for serine hydroxymethyltransferase. This leads to a stimulation of asparagine synthetase to provide nitrogen for asparagine-dependent glycine synthesis. This may provide an explanation of the observed chemotherapeutic synergism between asparaginase and methotrexate treatment.

Animals↗
PubMedDate not supplied

The effect of silyl substituted methotrexate in the treatment of experimental allergic encephalomyelitis in rats mediated by T-line cells.

The effect of methotrexate and of silyl-methotrexate were compared in the treatment of experimental allergic encephalomyelitis (EAE) mediated by T-line lymphocytes. It was demonstrated that, during the first three days after cell transfer, no difference between methotrexate and its silyl derivative could be seen. At a time when the cytotoxic lymphoblasts must have penetrated the blood brain barrier, only silyl methotrexate was able to prevent severe paralysis and death of the animals. It is suggested that the effect of N,N,O,O-Tetrakis (t-butyldimethylsilyl)-methotrexate, (N-4-N-(2,3-bis-t-butyldimethylsilyl-amino-6-pteridinyl-methyl)- methylamino-benzoyl-glutamic acid-bis-(t-butyldimethylsilyl)-ester), depends on the increased lipid solubility and permeability of the blood brain barrier of silylated drugs.

Animals↗
PubMed1986

Ten year's experience with methotrexate and folinic acid as primary therapy for gestational trophoblastic disease.

Methotrexate and folinic acid was administered as primary therapy in 185 patients with gestational trophoblastic disease between 1974 and 1984. Methotrexate and folinic acid induced complete remission in 147 (90.2%) of 163 patients with nonmetastatic disease and in 15 (68.2%) of 22 patients with low-risk metastatic disease. Sustained remission was achieved in 132 (81.5%) patients following only one course of chemotherapy. All patients with methotrexate resistance subsequently achieved remission with Actinomycin D or combination chemotherapy. Methotrexate when administered with folinic acid was associated with granulocytopenia, thrombocytopenia, and hepatotoxicity in 11 (5.9%), 3 (1.6%), and 26 (14.1%) patients, respectively. The human chorionic gonadotropin (hCG) regression curve served as a reliable guide for the administration of chemotherapy and enabled the attainment of a high remission rate while limiting chemotherapy exposure. Methotrexate and folinic acid achieves an excellent therapeutic outcome with limited chemotherapy exposure and effectively limits systemic toxicity.

Adolescent↗
PubMed1991

Effect of nitrous oxide and methotrexate on folate coenzyme pools of blast cells from leukemia patients.

The effects of methotrexate (inhibiting dihydrofolate reductase) and nitrous oxide (inactivating methionine synthase) on intracellular folate coenzyme levels of leukemic cells were studied. Blast cells from 10 cases of acute myeloid leukemia (AML) and 5 cases of acute lymphoid leukemia (ALL) were incubated with 5 x 10(-8) M [3H] 5-formyltetrahydrofolate (5-formylTHF) for 18 h to label intracellular folate pools, which were subsequently quantitated by high performance liquid chromatography (HPLC). In AML, 5-methylTHF made up 53% of the total folate pool followed by 10-formylTHF (26%), 5-formylTHF (10%), THF (9%) and DHF (1%). Cells from ALL differed from AML (p less than 0.05) with respect to 10-formylTHF (17%) and DHF (10%). Exposure to nitrous oxide (8 h) caused an equal decrease of 10-formylTHF and 5-formylTHF in both AML (30%) and ALL (45%), whereas 5-methylTHF increased (130%). Methotrexate (4 h, 10(-6) M) caused an accumulation of DHF and a decrease of 5-methylTHF in both AML (32%) and ALL (12%). A specific reduction of the 10-formylTHF (50%) and 5-formylTHF (25%) pools was noticed in ALL. Exposure to nitrous oxide prior to methotrexate treatment aggravated the reduction of 10-formylTHF and 5-formylTHF presumably by impaired replenishment from the 5-methylTHF pool. In conclusion, this study demonstrates a significant difference in folate coenzyme distribution between cells from AML and ALL. Moreover it is shown that nitrous oxide and methotrexate treatment of leukemic cells cause an accumulation of 5-methylTHF and DHF respectively at the expense of other folate forms. The presence of substantial amounts of DHF in cells from ALL together with the specific reduction of 10-formylTHF (necessary for purine synthesis) during MTX treatment may in part explain the efficacy of methotrexate in the treatment of ALL.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1989

The folate antagonist, methotrexate, is a potent inhibitor of murine and human cytomegalovirus in vitro.

Cytomegalovirus (CMV) is a major source of morbidity for immunocompromised patients, such as AIDS patients. The folic acid antagonists have not been explored as potential antiviral agents against CMV. We examined the effects of methotrexate, compared to acyclovir and ganciclovir, on both murine CMV (MCMV) and human CMV (HCMV) in vitro. Using a plaque assay in mouse embryo cells or human foreskin fibroblasts for MCMV and HCMV respectively, we found that methotrexate, in micromolar concentrations, was a potent inhibitor of both viruses. This effect was due to folic acid antagonism since folinic acid abrogated the antiviral effect of methotrexate, but not ganciclovir. Cellular toxicity due to methotrexate appeared insufficient to account for the antiviral effects. The ability of methotrexate to inhibit CMV in vivo merits exploration.

Acyclovir↗
PubMed1986

Increased protein ADPribosylation in HeLa cells exposed to the anti-cancer drug methotrexate.

DNA single-strand breaks (about 200-300 per genome) were transiently detected during the first hour when HeLa cells were incubated for up to 24 h with 100 microM methotrexate. There was an expected increase in ADPribosyltransferase activity, which reached a maximum 2-3-fold stimulation at 3 h but which was still greater than in control cells after 24 h. When hypoxanthine (25 microM) was present in the incubations together with the methotrexate the transferase was no longer activated, although basal, control levels of activity were still present. DNA strand breaks were reduced in number but were still just detectable under these conditions. Cellular NAD+ levels were mostly unaffected by the various drug treatments, except for a small transient decrease after 1 h, possibly as a result of the transferase activation. Methotrexate did not cause an increase in the rate of ADPribose degradation. Degradation of ADPribose residues labelled in a preincubation period in permeabilized cells was more extensive at pH 6.0 was a 50% loss of acid-insoluble radioactivity in 30 min at 26 degrees C. At pH 8.0 the loss did not exceed 30-35% even after 90 min incubation. The activation of the transferase is reflected in a general increase in protein ADPribosylation detected by autoradiography of 32P-labelled proteins in 6.25-18.25%T gradient acrylamide gels. There were three major acceptors with molecular masses of 17, 100 and over 100 kDa, which could be respectively a histone, a transferase-derived peptide fragment and the transferase itself. When ADPribosyltransferase was inhibited with 3-amino-benzamide DNA single-strand breaks were no longer detected. However, this had no observably signficant effect on the kinetics of loss of cell viability (from Trypan blue uptake), cell number or colony-forming ability. Similar results are observed in most cases when the activation of the transferase, resulting from the incubation of cells with methotrexate, is inhibited by hypoxanthine. We conclude from such observations that the enhanced protein ADPribosylation seen in the cells exposed to methotrexate is a direct consequence of drug-exposure, but does not have any significant influence over the course of events leading ultimately to cell death.

Adenosine Diphosphate Ribose↗
PubMed1993

Severe megaloblastic anemia in a patient receiving low-dose methotrexate for psoriasis.

Severe megaloblastic anemia with a normal white blood cell and platelet count developed in a patient with psoriasis vulgaris who was receiving long-term, low-dose methotrexate. We believe she had methotrexate-induced folate deficiency anemia with isolated inhibition of the erythrocytic bone marrow line. We review hematologic toxicity from low-dose methotrexate. Physicians caring for patients who receive low-dose methotrexate should be aware that an increase in the erythrocyte mean corpuscular volume may be a useful indicator of folate deficiency and impending toxicity. In addition, folate supplementation may prevent this toxicity (even in patients who do not appear clinically to be folate deficient), although whether methotrexate efficacy diminishes is controversial.

Adult↗
PubMed1991

Schedule-dependent synergism and antagonism between methotrexate and 6-mercaptopurine in a human acute lymphoblastic cell line.

We studied the combined cytotoxic effects of methotrexate and 6-mercaptopurine (6-MP) on a human acute lymphoblastic cell line (MOLT-3) in vitro according to various schedules. The combined effects were analysed with improved isobologram using the concept of additivity. Simultaneous and continuous exposure (72 h) to these two agents had subadditive to protective effects (antagonism). Partial simultaneous exposure to methotrexate (5 h) and 6-MP (72 h) showed additive to protective effects. Sequential exposure to methotrexate (5 h) followed by 6-MP (72 h) had an additive effect at 0 h and a supra-additive effect (synergism) at 3 h and 19 h intervals. Therefore, it would seem to be better to avoid the simultaneous administration of methotrexate and 6-MP when these two drugs are used in combination. Sequential administration of methotrexate first, followed by 6-MP at short intervals, is recommended.

Cell Division↗