June 20, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
In an overdose of β-blockers, bradycardia may be countered by atropine or transvenous pacing if severe. When an infusion is required, glucagon is logical because it stimulates the formation of cAMP by bypassing the occupied β-receptor.

June 19, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
Cardiac contraindications to β-blockade include severe bradycardia, preexisting high-degree heart block, sick sinus syndrome and overt left ventricular failure unless already conventionally treated and stable.

June 18, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
The four major mechanisms for β-blocker side effects are (1) smooth muscle spasm, (2) exaggeration of the cardiac therapeutic actions (bradycardia, heart block), (3) CNS penetration (insomnia, depression) and (4) metabolic side effects.

June 17, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
In diabetes mellitus, the risk of β-blockade in insulin-requiring diabetics is that the premonitory symptoms of hypoglycemia might be masked. There is a lesser risk with the cardioselective agents.

June 16, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
Esmolol (Brevibloc) is an ultrashort-acting β1-blocker with a half-life of 9 minutes, rapidly converting to inactive metabolites by blood esterases. Full recovery from β-blockade occurs within 30 minutes in patients with a normal cardiovascular system.

June 15, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
Sotalol (Betapace) is a unique nonselective β-blocker with Class 3 antiarrhythmic activity. It is licensed for life-threatening ventricular arrhythmias as well as maintenance of sinus rhythm in patients with atrial fibrillation or atrial flutter.

June 14, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
Propranolol (Inderal) is approved for so many different indications, including angina, acute MI, postinfarction secondary prevention, hypertension, arrhythmias, migraine prophylaxis, anxiety states and essential tremors.

June 13, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
The prototype β-blocker is propranolol, which is still used worldwide. By blocking β1-receptors, it affects heart rate, conduction and contractility, yet by blocking β2-receptors, it tends to cause smooth muscle contraction with risk of bronchospasm.

June 12, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
Third-generation β-blocker vasodilatory agents have added properties, acting chiefly through two mechanisms: first, direct vasodilation, possibly mediated by the release of nitric oxide and second, added α-adrenergic blockade.

June 11, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
First-generation nonselective agents, such as propranolol, block all the β-receptors (β1 and β2). Second-generation cardioselective agents, such as atenolol, metoprolol and bisoprolol, have selectivity for the β1 (largely cardiac) receptors.

June 10, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
The use of local β-blocker eye solutions is established for open-angle glaucoma. Care needs to be exerted with occasional systemic side effects such as sexual dysfunction, bronchospasm and cardiac depression.

June 9, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
β-blockade is used in thyrotoxicosis to control symptoms, although the hypermetabolic state is not decreased. β-blockade controls tachycardia and palpitations and reduces vascularity of the thyroid gland, which facilitates surgery.

June 8, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
β-blockade reduces the oxygen demand of the heart by reducing the double product (heart rate × BP) and by limiting exercise-induced increases in contractility. Of these, the most important and easiest to measure is the reduction in heart rate.

June 7, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
First-pass liver metabolism is found especially with the highly lipid-soluble compounds, such as propranolol, labetalol and oxprenolol. Major hepatic clearance is also found with acebutolol, nebivolol, metoprolol and timolol.

June 6, 2024

Nursing Tip of the Day! - Fundamentals

Category: Fundamentals 
The half-life of propranolol is only 3 hours, but continued administration saturates the hepatic process that removes propranolol from the circulation. The active metabolite 4-hydroxypropranolol is formed, and the half-life then becomes longer.