Nadolol (Corgard) is a non-selective beta blocker used in the treatment of high blood pressure and chest pain. Additionally, it is often prescribed in the treatment of atrial fibrillation, migraine headaches, and complications of cirrhosis.
Medical uses
Nadolol is used to treat hypertension and for long-term treatment of angina pectoris and is approved by the FDA for these purposes.
It is regularly used off-label for control of heart rate in people with atrial fibrillation, prevention of migraine headaches; prevention of bleeding veins in people with portal hypertension caused by cirrhosis; and to treat people with high levels of thyroid hormone.
Nadolol is one of the preferred beta-blockers in the management of patients with LQTS for shortening of the QT interval and prevention of ventricular arrhythmia. It is more efficacious than metoprolol in the prevention of breakthrough cardiac events while on therapy and is equivalent to propranolol. Nadolol has the advantage of once daily dosing and thus improved patient compliance. It has also been found to be useful (off-label) for several Neurological disorders such as the prevention of Migraine attacks, Attention deficit/hyperactivity disorder(ADHD) and its use has been explored as a treatment for essential tremor and Parkinson's disease but neither is well established.
Side effects
The most common side effects include dizziness and fatigue.
Contraindications
Nadolol and other beta blockers should be used with cautions in people with heart failure and its use should not be abruptly stopped. It is contraindicated for people with asthma, a slow heart rate and certain severe heart problems.
Mechanism of action
Nadolol is a non-selective beta blocker; that is, it non-selectively blocks both beta-1 and beta-2 receptors. It has a preference for beta-1 receptors, which are predominantly located in the heart, thereby inhibiting the effects of catecholamines and causing a decrease in heart rate and blood pressure. Its inhibition of beta-2 receptors, which are mainly located in the bronchial smooth muscle of the airways, leads to airway constriction similar to that seen in asthma. Inhibition of beta-1 receptors in the juxtaglomerular apparatus of the kidney inhibits the renin-angiotensin system, causing a decrease in vasoconstriction and a decrease in water retention. Nadolol's inhibition of beta-1 receptors in the heart and kidney leads to its effects on lowering blood pressure.
The drug impairs AV node conduction and decreases sinus rate.
Nadolol may also increase plasma triglycerides and decrease HDL-cholesterol levels.
Chemistry
Nadolol is a mixture of stereoisomers. It is polar and hydrophilic, with low lipid solubility.
See also
- Renin-angiotensin system
- Anti-hypertensive
- Cardiology