- MTX 20 mg/m2 per week , i.m. Throughout the maintenance treatment should seek to retain WBC counts between 2.5 and 5x109 / L and platelet counts above 120x109 / L. If these lower limits should be reduced is decreased by 20 % doses of MP and MTX. If the numbers of leukocytes exceed 5x109 / L will increase by 20 % the dose of MP (50 to 60 mg/m2 )