Vibrotactile sensation and response to nifedipine dose titration in primary Raynaud's phenomenon

The clinical response to two doses of sustained-release nifedipine was assessed during a double-blind, randomized, placebo-controlled trial in 22 patients with primary Raynaud's phenomenon. Nifedipine at doses of 20 mg and 40 mg daily reduced the mean number of attacks by 40% compared with placebo with no significant differences between the two doses in the number of attacks or their severity. Unwanted effects were more common and more persistent with the higher dose of nifedipine. Fingertip vibrotactile thresholds measured at 31.5 and 125 Hz were unchanged by treatment with nifedipine. There was, however, a correlation between the pretreatment threshold at 125 Hz and the response to treatment with nifedipine, the most favorable responses occurring in patients with the lowest thresholds.