This may affect how long the drug works and what side effects you may have. Because of the differences, your doctor will decide which type and dosage of beta-blocker are right for you. Most of the side effects are minor, but people with some conditions need to use beta-blockers with caution. If you have diabetes, you should watch your blood sugar level closely because your requirement for medication or insulin may change. Make sure all your doctors know you have diabetes, and inform your doctor of any changes in your blood sugar levels.
Some people complain of cold hands or feet while on the drugs.
Others with a blood vessel condition called Raynaud's phenomenon may become worse. Patients with coronary heart disease and angina may become worse if they stop taking the blockers suddenly. Beta-blockers sometimes cause fatigue, depression and nightmares. Beta-blockers may make some people with congestive heart failure worse. On the other hand, some people with severe congestive heart failure feel much better with the medicine.