Systemic Methotrexate Administration Research Articles

TUBAL PATENCY AFTER LOCAL METHOTREXATE INJECTION FOR TUBAL PREGNANCY

Tubal patency was investigated by hysterosalpingography in 21 of 37 patients with unruptured tubal pregnancy treated by local methotrexate injection at laparoscopy. 18 of the 21 patients had bilateral tubal patency, and the only tube of a patient with a single fallopian tube was also patent. 6 subsequent intrauterine pregnancies have so far been recorded. Local methotrexate injection into the tubal pregnancy may provide an efficient and safe alternative to surgery in early unruptured ectopic pregnancy.

Dihydrofolate reductase-activity in brain tissue. Effect of X-irradiation.

The mechanism responsible for the toxic late effects of cranial irradiation, followed by the administration of systemic methotrexate (MTX) on brain tissue, is still under discussion. We studied the influence of X-irradiation on dihydrofolate reductase (E.C. 1.5.1.3) activity (DHFR), the enzyme inhibited by MTX. New Zealand white rabbits, 6-9 weeks old, underwent 24 Gy fractionated or 20 Gy single-dose brain irradiation using a 60Co source. Before, immediately following, and 1, 2, 4, 12 weeks after irradiation, DHFR was measured in brain and liver tissue by a photometric assay. DHFR in brain tissue was 11.9 +/- 2.9 mU/g wet weight (ww) X h and in liver tissue 121.8 +/- 24.2 mU/g ww X h. Fractionated brain irradiation with 2 Gy per day produced no significant changes in brain DHFR. Single-dose cranial irradiation significantly decreased brain DFHR (7.3 +/- 0.6 mU/g ww X h). Suppression of the developmental increase of DHFR by X-irradiation in young rabbits could be excluded by determining the unchanged brain-to-liver ratios of DHFR in the animals with fractionated brain irradiation.

Combined Intraarterial and Systemic Chemotherapy for Intracerebral Tumors

Twenty-six patients with intracerebral tumors (predominantly gliomas) were treated with intraarterial BCNU, VM-26, and cisplatin combined with the systemic administration of VM-26, methotrexate, vincristine, bleomycin, and procarbazine. Oral glycerol was given before i.v. VM-26. Twelve patients responded (46% of all patients and 63% of the fully evaluable patients). The response rate for gliomas was 50% if all patients were considered and 71% if only fully evaluable patients were considered. The response rate did not seem to be affected by glioma grade, prior chemotherapy, or pretreatment performance status. Median time to tumor progression for responders was 19 weeks. Median survival from initiation of treatment was 21 weeks for evaluable patients and 17 weeks for all patients. Median survival from initial diagnosis was 55 weeks. Myelosuppression was dose-limiting for the systemic chemotherapy. Reversible neurological toxicity was common, but tolerable. One patient developed ipsilateral blindness, and two patients developed prolonged neurological toxicity. Pulmonary toxicity was also seen. Vertebral artery infusions proved feasible, although difficult and more toxic than carotid infusions. Overall, this regimen was not more active than the intraarterial combination of BCNU, VM-26, and cisplatin without the systemic chemotherapy. Further studies of more intensive intracarotid therapy combined with different systemic drugs are being initiated.

Malignant Histiocytosis Resistant to Anthracycline

A 36-year-old woman, presenting with fever, pancytopenia, hepatosplenomegaly, and striking effacement of the bone marrow by true malignant histiocytes, was found to have no benefit from the systemic administration of cyclophosphamide, vincristine sulfate, doxorubicin, prednisone, and high-dose methotrexate with calcium leucovorin rescue. Striking histologic and clinical improvement was noted after the administration of two cycles of etoposide and amsacrine, each cycle consisting of 100 mg/sq m/day of each agent for five days. We believe that this therapy should be considered for future patients demonstrating aggressive presentations of malignant histiocytosis.

Persistence of Antifolate Activity in Skin of Rats Following Systemic Administration of Methotrexate

Studies of the time course of methotrexate-derived antifolate activity (methotrexate activity) in plasma and skin of rats have been carried out to evaluate the hypothesis that the formation of therapeutically active poly-gamma-glutamyl conjugates of methotrexate in skin after systemic administration of the drug will result in the prolongation of methotrexate effects in skin. Such a finding may eventually bear on the use of the drug in the treatment of psoriasis. Three groups of 4 rats received a single i.v. dose of methotrexate, 5, 20, or 40 mg/kg, respectively. Serial skin and plasma samples were obtained over 48 h from each rat and analyzed for methotrexate activity by a dihydrofolate reductase enzyme inhibition assay. The values of pharmacokinetic parameters describing the disposition of the drug were calculated from plasma data using standard methods. Skin to plasma ratio of methotrexate activity was also calculated each time a skin sample was obtained. Pharmacokinetic parameter values and skin to plasma ratios were not significantly different between doses. Methotrexate activity declined biexponentially in plasma and skin. The terminal half-life in plasma (mean +/- SD) was 20.3 +/- 9.2 h. At early times, methotrexate activity in skin was less than plasma, but at later times activity in skin was an order of magnitude greater than that in plasma. In a preliminary study to determine whether the persistent activity in skin is associated with the presence of poly-gamma-glutamyl conjugates of methotrexate, a rat was dosed with tritiated methotrexate, 0.18 mg/kg, i.v., and skin was obtained 24 h later. Skin homogenate was treated with papain and applied to an anion-exchange column for cleanup prior to injection on a reversed-phase high-pressure liquid chromatography system. Methotrexate poly-gamma-glutamates were identified by elution with authentic standards and specific hydrolysis with carboxypeptidase G1.

Pulpal responses to operative procedures in rats receiving systemic methotrexate

The systemic administration of methotrexate in nonlethal doses impairs the ability of the laboratory rat to localize an inflammatory response to operative dental procedures that result in exposures within the pulpal tissue. The pulpal healing response within these animals is thus greatly compromised.

Unexpected toxicity of combined modality therapy for small cell carcinoma of the lung a southwest oncology group study

Combination chemotherapy with cyclophosphamide, vincristine, methotrexate and Adriamycin was delivered to 35 patients with small-cell carcinoma of the lung (28 with extenstive and 7 with limited disease), including elective administration of intrathecal methotrexate. Whole-brain irradiation (3000 rad in 10 fractions) was then administered, with concomitant systemic cyclophosphamide and methotrexate for patients with extensive disease. Those with limited disease received concomitant chest irradiation without chemotherapy. Maintenance therapy then involved cyclophosphamide 750 mg/m 2 day 1, and methotrexate 30 mg/m 2days 1 and 8, every 3 weeks. In only 2 patients reinduction was carried out at 24 weeks with the original chemotherapy. Myelosuppression was severe; there were at least 2 drug-related deaths from this cause in the induction period, and 15 febrile episodes with leukopenia. Stomatitis was more frequent and more severe in “maintenance” than in “induction” courses, especially the first maintenance course which was given with concomitant whole-brain irradiation. In addition, 13 episodes of unusual toxicity occurred in close temporal relation to systemic methotrexate administration, usually associated with stomatitis, in patients who were on maintenance therapy. These included 3 episodes of loss of consciousness, 4 of generalized erythroderma, 2 of “flu”-like syndrome, and I each of the following: fatal, bilateral interstitial pneumonia; reversible, eosinophilic pleural effusion; acute myocardial infarction; and renal compromise with hematuria. As a result of this unexpected and protean toxicity, the pilot study was discontinued. However, at this time seven patients (4 with extensive and 3 with limited disease) remain in complete remission.

Effects of Methotrexate and Hydroxyurea on Psoriatic Epidermis

Systemic administration of methotrexate produced histologically damaged cells in biopsy specimens of skin taken from areas clinically consistent with psoriasis. These cells were not found in the epidermis of uninvolved, normal appearing skin biopsy specimens taken from the same patient at the same time intervals. In addition, the appearance of the damaged cells was related to the dosage of methotrexate administered. Similarly damaged cells were seen after administration of hydroxyurea. Again, selective cytotoxicity was noted in that damaged appearing cells were present in involved psoriatic epidermis and were absent in uninvolved normal appearing epidermis. No damaged cells were seen in biopsy specimens obtained from untreated psoriatic patients or patients treated with steroids administered topically or systemically.