ORAL-ADMINISTRATION OF AN EASILY PREPARED SOLUTION OF INJECTABLE METHOTREXATE DILUTED IN WATER - A COMPARISON OF SERUM CONCENTRATIONS VS METHOTREXATE TABLETS AND CLINICAL UTILITY

Objective. To investigate whether the injectable formulation of methot rexate (MTX) given as an easily prepared oral solution of MTX diluted in water results in serum concentrations similar to those obtained wit h MTX tablets, to describe an easy and safe method of dispensing the d rug. Methods. Six patients (5 women, 1 man) with rheumatoid arthritis were given 10 mg of liquid MTX orally. The liquid was prepared by dilu ting 0.4 ml of the injectable formulation of MTX (50 mg/2 ml) in 8 oun ces of water. One to 2 weeks later these patients were given 10 mg of MTX in the tablet form. MTX serum concentrations were determined using a fluorescence polarization immunoassay. The area under the concentra tion vs time curve (AUC), maximum concentration (C-max), and the time to reach maximum concentration (t(max)) were determined from the resul ting concentration vs time curves. Results. There was no statistical d ifference in the variables measured (AUG, C-max, t(max)), demonstratin g comparable concentrations with these 2 methods of MTX administration . Patients found the medication easy to administer, potential hazards with the use of needles were avoided, and the cost of the drug was gre atly decreased. Conclusion. The administration of this easily prepared MTX solution is an alternative to the conventional administration of MTX tablets, and may be of particular benefit in patients with financi al limitations.