Precautions

Beta blockers should not be given to patients with bronchospasm or asthma or to those with a history of obstructive airway disease. This applies even if it is a cardioselective (beta ₁) blocker. Other contra-indictions include metabolic acidosis, sinus bradycardia, or partial heart block.They should not be given to patients with congestive heart failure unless their heart failure is controlled and even then great care is still necessary. Patients with phaeochromocytoma should not recieve beta blockers without concomitant alpha-adrenoceptor blocking therapy.

Beta blockers may mask the symptoms of hyperthyroidism and hypoglycemia. They may unmask myasthenia gravis. Psoriasis may be aggravated. Some elderly patients with hypertension may not respond well to a beta blocker as well as a younger patient..

Dosage will need to be reduced in patients with renal or hepatic dysfunction.

Abrupt withdrawal of beta blockers has sometimes resulted in angina, myocardial infarction, ventriculararrhythmias, and death. Patients who are on beta blockers long-term should have their medication discontinued slowly over a period of 1-2 weeks.

Patients with hypersensitivity to stings and antigens may find that their reaction to stings etc is increased. Therefore causing a greater incedence of anaphylactic shock.