Protocol for Initiating Methotrexate
A common protocol used to treat inflammatory arthritis (e.g. RA or psoriatic). Usually started after consultation with a rheumatologist.
Prior to starting Methotrexate:
- CBC, ESR, Liver Function Tests (ALT, AST, ALP, Total bilirubin) and Creatinine
- Hepatitis B and C serology.
- Chest X-Ray within the previous 3 months.
Follow Up Lab tests: CBC, ESR, LFT's, Creatinine
- Every 2 weeks for two months
- Every 3 weeks for three months
- Monthly for three months
- Every two months thereafter
- Each time the dose is increased, tests are checked two weeks later
Dose of Methotrexate:
- 10 mg PO once weekly
- Folic acid is also given to patients at 1 mg PO daily - seven days per week.
- In two weeks, if tolerated, the dose of methotrexate is increased to 15 mg po once weekly (to increase tolerability, this dose may be split into 10 mg and 5 mg, twelve hours apart).
- In a further two weeks, if tolerated, the dose may then be increased to 20 mg po once weekly (to increase tolerability, the dose may be split into 10 mg po twelve hours apart).
- The 20 mg per week dose may be continued, if tolerated, for a total of three months. If there is no improvement, the dose may then be increased by 2.5 mg once monthly, if tolerated, to a maximum of 25 mgs once weekly. Otherwise, the dose may continue at 20 mgs weekly.
- Additionally, the Methotrexate may be changed to an IM/SC preparation if the Methotrexate is not tolerated or efficacious PO. The IM/SC dose will be the same as the PO dose.
- Infection and Methotrexate: When patients should require antibiotics for an infection while on Methotrexate, the Methotrexate should be held until the antibiotics have been completed and the infection has resolved.