The evolution of hypertension treatment in Belgium, a pharmacoepidemiological study.

Objectives: The aim of this paper is to study the number of patients treated for hypertension and the evolution in usage of different classes of antihypertensive medication.

Methods: Data from 1997 to 2009 was extracted from Pharmanet, a nation-wide database of prescriptions of reimbursed medication in Belgium.

Results: In 2009, 25% of women and 20% of men were prescribed at least one antihypertensive drug. Prescription rates rose with age but already 25% of the population aged between 41 and 60 years were treated. More than 50% of the Belgians above 60 years took antihypertensive medication. From 1997 to 2009, a rise in absolute prescription rate was observed for all antihypertensive drug classes. Diuretics and beta blockers remain by far the most frequently delivered drugs with stable prescription rates of 30% over this period. The largest rise is observed for angiotensin II receptor blockers (ARBs), which were only sporadically prescribed in 1997 and now account for 10.5% of the delivered antihypertensive drugs. A small rise is also noted for angiotensin-converting enzyme inhibitors (ACE-inhibitors) (12.3% in 1997 vs 15.6% in 2009). Their success comes at the expense of calcium antagonists, of which the delivered amount declined from 19.8% in 1997 tot 14.1% in 2009. A progressive rise in the prescription of fixed combination products is observed (from 15% in 1997 to 21% in 2009), and can probably be attributed to their growing availability but also to the recent guidelines, promoting their usage.

Conclusion: Above age 60, the majority of the Belgians are treated with antihypertensive medication. There is a growing tendency for the use of renin angiotensin aldosterone system (RAAS) blockers and fixed combination products.