Complex Regional Pain Syndrome (CRPS) is the new name for entities formerly known mostly as
Reflex Sympathetic Dystrophy and
Causalgia. Treatment of CRPS with either the
calcium channel blocker nifedipine or the alpha-sympathetic blocker
phenoxybenzamine was assessed in 59 patients, 12 with early stages of CRPS, 47 with chronic stage CRPS. In the early stage CRPS patients, 3 of 5 were cured with
nifedipine and 8 of 9 (2 of whom had earlier received
nifedipine) with
phenoxybenzamine, for a cure rate of 92% (11 out of 12). In the chronic stage CRPS patients, 10 of 30 were cured with
nifedipine;
phenoxybenzamine cured 7 of 17 patients when administered as a first choice and another 2 of 7 patients who received
nifedipine earlier, for a total late stage success rate of 40% (19 out of 47). The most common side effects necessitating discontinuing the
drug were
headaches for
nifedipine and orthostatic
dizziness,
nausea and diarrhoea for
phenoxybenzamine. All male patients on
phenoxybenzamine experienced
impotence, but this did not lead to discontinuing this agent and immediately disappeared after stopping the
drug. These results once again stress the importance of early recognition of CRPS, and treatment with either of these drugs could be considered as a first choice for early CRPS, especially because in this series this treatment was not combined with
physical therapy making it very cost-effective. In the chronic stage of CRPS, treatment with these drugs was much less successful (40%), even though it was always combined with
physical therapy, but it can still be considered, either as a first choice or when other types of treatment have failed.