Why is methotrexate tablet taken once a week?

Methotrexate tablets are taken once a week due to the drug's slow metabolism, the need to reduce the risk of bone marrow suppression, minimize gastrointestinal irritation, align with the treatment's onset cycle, and prevent liver and kidney damage. This dosing frequency is a scientifically balanced approach that optimizes both efficacy and safety. If persistent vomiting, fever, or signs of bleeding occur after taking the medication, medical attention should be sought promptly.

1. Slow Drug Metabolism: Methotrexate has a long half-life in the body and is slowly metabolized and excreted. Administering it once weekly prevents excessive drug accumulation, reduces the risk of toxicity, and ensures safe use.

2. Reduced Risk of Bone Marrow Suppression: The drug can suppress rapidly dividing bone marrow cells. A weekly dosing interval allows sufficient time for recovery of hematopoietic function, thereby reducing severe adverse reactions such as leukopenia and thrombocytopenia.

3. Reduced Gastrointestinal Irritation: Methotrexate often causes gastrointestinal side effects such as nausea, vomiting, and diarrhea. Intermittent dosing reduces continuous mucosal irritation, improving patient tolerance.

4. Alignment with Therapeutic Onset Cycle: The therapeutic effect for conditions like rheumatic autoimmune diseases and cancers develops over a relatively long period. Weekly administration maintains effective plasma concentrations while avoiding additional harm from frequent dosing.

5. Prevention of Liver and Kidney Damage: As the drug is primarily metabolized through the liver and kidneys, frequent dosing increases their workload. Once-weekly dosing reduces the risk of organ damage, making it especially suitable for long-term users.

Methotrexate tablets must be taken strictly according to the prescribed time and dosage; patients should not alter the frequency on their own. Maintain a light diet during treatment and avoid alcohol consumption. Follow a regular作息 (daily routine), avoid fatigue, and have liver and kidney function and blood counts monitored regularly.