Level 2: Mid-level evidence
A recent systematic review reported that greater heart rate reductions associated with beta blocker use (mainly atenolol) for treatment of hypertension appeared to be correlated with increased rates of adverse outcomes (J Am Coll Cardiol. 2008;52:1482-1489). This prompted a review of the information in DynaMed about the use of beta blockers as first-line therapy for hypertension.
A Cochrane review concluded that beta blockers are not indicated as first-line therapy for hypertension (Cochrane Database Syst Rev. 2007;:CD002003). Beta blockers were no better than placebo in prevention of coronary heart disease or mortality, and they had only a very small advantage in prevention of stroke. Patients given beta blockers tended to have worse outcomes than those given other antihypertensive drug classes. Most trials used atenolol, so it is unclear if conclusions apply to other beta blockers. Another systematic review found benefit from beta blockers (compared with placebo) to be limited to younger patients, with no superiority compared with other antihypertensive drug classes in this age group (CMAJ. 2006;174:1737-1742). This same review found beta blockers less effective than other antihypertensive agents in older patients. Thiazide-type diuretics continue to be recommended as the most cost-effective first-line therapy for hypertension (CADTH Health Technology Assessment. 2007:95, and JAMA. 2003;289:2534). Comorbidities, such as congestive heart failure or history of MI, may need to be taken into account in selecting the best medication for initial treatment of hypertension.