The frequency of methotrexate treatments for children can vary depending on the specific condition being treated and the individual patient's response to the medication. Methotrexate is a commonly used medication for various conditions in children, including psoriasis, juvenile idiopathic arthritis (JIA), and certain types of cancer.

For psoriasis, the American Academy of Dermatology (AAD) states that methotrexate is typically prescribed once a week [3]. However, the dosage and frequency may be adjusted based on the child's response and tolerance to the medication. It is important to note that methotrexate is usually used as a second-line treatment for psoriasis in children, when other therapies have not been effective or appropriate [3].

In the case of JIA, methotrexate is often used as a first-line treatment. According to a study published in the National Center for Biotechnology Information (NCBI), the usual dosage of methotrexate for JIA ranges from 10 to 15 mg/m² per week [2]. The frequency of administration is typically once a week, but it can be adjusted based on the child's response and any potential side effects [2].

When it comes to cancer treatment, methotrexate is used in higher doses and more frequently. The specific regimen depends on the type and stage of cancer being treated. The Drug Patent Watch website provides information on the different formulations and dosages of methotrexate used for cancer treatment [1]. However, it is important to note that cancer treatment protocols are complex and individualized, and the frequency of methotrexate treatments can vary significantly.

In summary, the frequency of methotrexate treatments for children depends on the specific condition being treated. For psoriasis, it is typically administered once a week [3]. For JIA, it is usually given once a week with a dosage ranging from 10 to 15 mg/m² [2]. In cancer treatment, the frequency and dosage can vary significantly depending on the specific protocol [1].

Sources:
[1] Drug Patent Watch. Methotrexate - Trademark Details. Retrieved from https://www.drugpatentwatch.com/p/tradename/METHOTREXATE
[2] National Center for Biotechnology Information (NCBI). Methotrexate for the Treatment of Juvenile Idiopathic Arthritis in the Biologic Era: Is It Time to Change Paradigms? Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5153332/
[3] American Academy of Dermatology (AAD). Methotrexate. Retrieved from https://www.aad.org/public/diseases/psoriasis/treatment/medications/methotrexate