We investigated the effect of gallopamil administration during a cold pressor test (CPT) in 18 patients suffering from chronic angina (CA) and in 21 healthy subjects. CA patients showed increased basal levels of beta-thromboglobulin and thromboxane B2 compared to control patients and normal plasma levels of catecholamines. CPT caused plasma catecholamines, beta-thromboglobulin and TxB2 levels to rise. This rise was greater in CA patients than in control patients. Administration of gallopamil (50 mg kg-1 three times a day for 30 days) reduced plasma levels of catecholamines, beta-thromboglobulin and TxB2 blood concentrations either under basal conditions or after CPT. Our data suggest that gallopamil is able to modulate the response induced by adrenergic stress.