[Evening dosing of antihypertensive drugs - future studies should be awaited before changing clinical practice]

Night-time blood pressure is an independent prognostic marker for cardiovascular disease. Evening dosing of antihypertensive agents can reduce night-time blood pressure and restore night-time blood pressure dipping pattern. In the Hygia Chronotherapy Trial, evening dosing of antihypertensive agents was compared to morning dosing, with dramatic effects on cardiovascular events and total mortality. We review possible limitations of the Hygia trial, including aspects of randomization, allocation concealment, outcome reporting and imbalance between groups. Based on these limitations, the trial should be interpreted with caution and future studies should be awaited before changing clinical practice.