The effect of calcium-entry blocker nifedipine on coldinduced digital vasospasm: a double-blind crossover study versus placebo: Nilsson H, Jonason T, Leppert J, Ringqvist T. Acta Med Scand 1987;221:53–60

Abstract

The authors evaluate the effect of the calcium-entry blocker nifedipine on digital vasospastic disease of idiopathic or traumatic origin. Twenty-eight patients were tested with a double-blind, crossover technique. Digital blood pressures during local cooling were measured by the Nielsen-Lassen method. Nifedipine 10 mg three times a day was initially administered and then the dose was increased to 20 mg three times a day for 1 week. There was a significant increase in the digital blood pressures with nifedipine for the total study group. Symptomatic improvement was significant for the total group and for those with idiopathic vasospastic disease. Twenty patients reported symptoms during active treatment, seven of these during the second week of higher dose therapy. One patient had intolerable side effects from the active drug and stopped the medication. In contrast, eight patients receiving placebo had similar symptoms. Headache (14 patients) and dizziness (14 patients) were the most common symptoms reported. The authors conclude that nifedipine is useful for relieving cold-induced symptoms and elevating digital blood pressure with cold-induced vasospastic disease, especially of the idiopathic form. The cold provocation test that they used mimics the actual situation that induces Raynaud's phenomenon. Symptomatic improvement was not significant in the group with traumatic vasospastic disease. The authors attribute this to complex symptomatology and the degree of cold-induced vasospasm. They point out that there may be differences in response to drug therapy depending on underlying ideologic factors and structural vascular changes. Furthermore they underline the need for careful individual dosing to limit the side effects.