Beta blockers have a wide range of side-effects,
including bradycardia, wheezing or unmasking
of asthma, masking of hypoglycaemia, sleep
disturbances, fatigue, exercise intolerance, erectile
dysfunction, glucose intolerance, worsening of
peripheral vascular disease, drowsiness, Raynaud’s
phenomenon, heart failure, dyslipidaemia, and
precipitation of angina with sudden withdrawal.
Aldosterone antagonists can cause life-threatening
hyperkalaemia, especially in patients with chronic
kidney disease (CKD) and concomitant use of ACE
inhibitors and NSAIDs. Other side-effects include
gynaecomastia, breast tenderness, menstrual
irregularities, gastric ulcers, and erectile dysfunction.
Generally, these complications can be avoided by
using low doses (50 mg maximum), avoiding their
use in high-risk situations, e.g. in the presence of
CKD, and avoiding the use of NSAIDs.