Isosorbide dinitrate or nifedipine: which is preferable in the medical therapy of achalasia?

Oesophageal motor activity was recorded manometrically with a low compliance system in 16 patients with achalasia and a slightly dilated oesophagus. After a basal recording period, nifedipine 20 mg was given sublingually to 9 patients and isosorbide dinitrate 5 mg to another 7 patients. Lower oesophageal sphincter pressure (LESp) and oesophageal body pressure wave amplitude were measured for 60 min after drug administration. Both drugs decreased LESp and pressure wave amplitude, but the effect of isosorbide dinitrate was faster and more intense than that of nifedipine. There was a lower inhibitory effect of nifedipine on the amplitude of pressure waves than on LESp, while isosorbide dinitrate inhibited with a similar intensity both LESp and pressure waves.