Pterin Injection Special Precautions

Methotrexate should be administered with caution in the following: Patients with kidney failure (elimination of this drug may be delayed), liver impairment, diarrhea or ulcerative stomatitis (splanchnic perforation may result in hemorrhagic enteritis and death), gastric ulcer or colitis ulcerativa, hematologic disorder, bone marrow depression, chickenpox (fatal systemic impairment may occur), complicated infections and mental disorder.
Since crucial adverse effects, such as bone marrow depression, hepatic impairment and renal impairment may occur, a patient's condition should be monitored and clinical tests (e.g., blood test, hepatic function test, kidney function test, urine test) should be performed frequently. If any symptoms occur, appropriate therapy such as reduction or discontinuance of the dosage should be instituted.
When elements of blood counts have increased, the administration should be discontinued, and supportive therapy such as blood transfusion or reverse barrier nursing should be instituted.
Hemopoietin depression even at low-dose may occur suddenly.
Bleeding may be a manifestation of infection.
The renal impairment by the administration of this drug is due primarily to the precipitation of methotrexate and 7-hydroxymethotrexate in the renal tubules. Close attention to renal function including adequate hydration, urine alkalinization, and elimination by urine and measurement of serum methotrexate and creatinine levels are essential for safe administration.
Methotrexate-induced lung disease is a potentially dangerous lesion, which may occur acutely at any time during therapy and which has been reported at doses as low as 7.5 mg/week. It is not always fully reversible. When pulmonary disease is suspected, lung function test, such as baseline measurement is effective.
Since in low-dose, long-term therapy of methotrexate, liver toxicity may occur, hepatic function tests should be performed regularly. If any symptoms occur, the administration should be discontinued for at least 2 weeks.
The effects on spermiogenesis, ovogenesis by the administration of this drug may decrease reproductive function reversibly; pregnancy should be avoided at least for 6 months after therapy. Since this drug has immunosuppressive function, it may decrease immune response to vaccine.
In the concomitant administration with live vaccine, serious antigen response may occur.
Since the drug contains tartrazine as a coloring agent, administration should be cautioned in patients with hypersensitivity to the drug or a history of allergy.
Use in Children: Safety in prematures, neonates and infants (not more than 1 year) has not been established.
Use in Elderly: Clinical pharmacology in elderly has not been studied. The elderly have high reserves of folic acid and low hepatic and renal function; therefore, they should be administered with low doses of methotrexate and monitored for initial signs of toxicity.