Maintenance dose of penicillamine in rheumatoid arthritis: a comparison between a standard and a response-related flexible regimen.
There is much individual variation in the response of rheumatoid arthritis (RA) to penicillamine, some patients deriving benefit from very small doses. A dose of 750 mg daily is widely regarded as standard, and, while their RA commonly responds, many patients discontinue treatment because of adverse reactions to penicillamine. A more flexible prescribing policy might be more successful in the long term and was tested in 1 group of 20 patients, another receiving a 'standard' regimen, each beginning treatment at a low dose level. Of those who were given increases of dose only if response was poor 17 completed 1 year of treatment on an average maintenance dose of 308 mg daily, but only 11 of the other group on an average dose 613 mg daily. Proteinuria, which was found only in the latter group accounted for 6 withdrawals, all at doses of 625 mg daily or above. The reduction in rheumatoid activity appeared to be of about the same degree among the members of both groups who completed 12 months of treatment. Penicillamine should be given initially in a low dose and this should be raised only if there is lack of response after at least 4 weeks.