To evaluate efficacy of phenytoin in modifying the course of rheumatoid arthritis (RA) by comparing it to gold (auranofin) and chloroquine.
A double blind, randomized study of 6 months' duration was conducted at the Nizam Institute of Medical Sciences, Hyderabad, India. One hundred and thirty-two patients with active RA (defined by the 1987 ARA criteria) were entered into the study and randomized into 3 groups: phenytoin, chloroquine, or auranofin.
Full data were evaluable in 100 patients who satisfactorily completed the protocol (phenytoin, 35; auranofin, 30; and chloroquine, 35). Twenty-four patients were noncompliant and did not take medication or return for evaluation; 8 patients had the drug withdrawn because of side effects before study completion. For each of the 3 drugs all clinical and laboratory variables improved when pre and posttreatment values (p < 0.05 to 0.001) were compared. There was a greater reduction in posttreatment mean morning stiffness in the chloroquine group than in the phenytoin and auranofin groups (p < 0.05). Posttreatment grip strength was also greatest in the chloroquine group. On the other hand, there were statistically significant decreases in IgM levels in both the phenytoin and auranofin groups (p < 0.001), but not with chloroquine. Among the 53 patients with a disease history of 3-6 months, global outcome was best with phenytoin (16/17), compared to chloroquine (12/18) and auranofin (12/18) (p < 0.03). However, there was no such difference in the 47 patients in all 3 groups with a disease history longer than 6 months. Eight patients had side effects (phenytoin, auranofin, 2; chloroquine, 1) requiring withdrawal of the drug. However, the incidence of side effects was not significantly different for the 3 drugs.
Our data indicate that phenytoin is comparable to auranofin and chloroquine in its efficacy in RA and may be considered an alternative disease modifying agent for RA.