It is available in tablet form ... pressure), such as Lopressor (metoprolol) or Tenormin (atenolol), can cause an additive effect with amlodipine. This, in turn, can cause low blood pressure ...

Objective: The aim of this study was to compare the antihypertensive efficacy and tolerability of the calcium channel antagonist amlodipine ... by a 4-day placebo drug-free period.