Loratidine improves ischemic parameters of exercise stress test in patients with acute myocardial infarction

This study sought to determine whether adding an anti-histaminic medication, loratidine, to anti-ischemic treatment would ameliorate or improve ischemic parameters induced by exercise stress test in patients who suffered an acute myocardial infarction.

Twenty stable patients with acute inferior myocardial infarction who had a positive EST were randomly allocated into 2 groups, A and B. Patients in group A and B received a 10 mg loratidine tablet added daily to their anti-ischemic regimen for 7 days during the second and third week post-event, respectively. At the end of each period they underwent an exercise stress test (EST). Exercise parameters in each group were then compared before and after loratidine therapy.

Both groups showed improvements in exercise parameters after loratidine therapy compared to basal EST results. ST(max) ( group A: 1.9 +/- 0.74 vs 0.9 +/- 1.29 mm, P = .046; group B: 2.5 +/- 0.71 vs 1.4 +/- 1.17 mm, P = .041), ST(lead) ( group A: 3.4 +/- 1.08 vs 1.5 +/- 2.12, P = .027; group B: 4.6 +/- 1.71 vs 2.22 +/- 2.25, P = .011), ST(total) ( group A: 4.7 +/- 2.18 vs 2.1 +/- 3.11 mm, P = .024; group B: 7.9 +/- 2.92 vs 3.33 +/- 3.81 mm, P = .005).

Our study revealed that loratidine, a histamine-1 receptor blocker, improves ischemic parameters of EST when given as additive therapy to a routine anti-ischemic regimen during the sub-acute phase of myocardial infarction.