Nadolol
Encyclopedia
Nadolol is a non-selective beta blocker
used in the treatment of high blood pressure
, migraine headaches
, and chest pain.
; 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 catecholamine
s 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 airway
s, 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
triglyceride
s and decrease HDL
-cholesterol
levels.
approved indications for the treatment of hypertension
and for the long-term treatment of angina pectoris.
(e.g. patients with congestive heart failure
or myocardial infarct
) should avoid nadolol as it inhibits sympathetic function. Nadolol is also contraindicated in patients with bradycardia
(slow heart rate) because of its vasodilatory effects and tendency to cause bradycardia.
Because of its beta-2 activity, nadolol causes pulmonary bronchoconstriction and should be avoided in asthma
patients in preference of a beta-1 blocker
. (There may be new evidence indicating that long-term non-selective beta-blocker use may actually prove to be beneficial in mild asthma.)
As nadolol, like other beta-2 blockers, inhibits the synthesis and release of glucose
in response to hypoglycemia
, it slows patients' recovery from acute hypoglycemic episodes and should be avoided in patients getting treatment for their diabetes mellitus. In patients with insulin
-dependent diabetes, a selective beta-1 blocker is preferred over non-selective blockers.
Beta blocker
Beta blockers or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists or beta antagonists, are a class of drugs used for various indications. They are particularly for the management of cardiac arrhythmias, cardioprotection after myocardial infarction ,...
used in the treatment of high blood pressure
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, migraine headaches
Migraine
Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...
, and chest pain.
Pharmacology
Nadolol is a non-selective beta blockerBeta blocker
Beta blockers or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists or beta antagonists, are a class of drugs used for various indications. They are particularly for the management of cardiac arrhythmias, cardioprotection after myocardial infarction ,...
; 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
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
, thereby inhibiting the effects of catecholamine
Catecholamine
Catecholamines are molecules that have a catechol nucleus consisting of benzene with two hydroxyl side groups and a side-chain amine. They include dopamine, as well as the "fight-or-flight" hormones adrenaline and noradrenaline released by the adrenal medulla of the adrenal glands in response to...
s and causing a decrease in heart rate
Heart rate
Heart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....
and blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
. Its inhibition of beta-2 receptors, which are mainly located in the bronchial
Bronchus
A bronchus is a passage of airway in the respiratory tract that conducts air into the lungs. The bronchus branches into smaller tubes, which in turn become bronchioles....
smooth muscle
Smooth muscle
Smooth muscle is an involuntary non-striated muscle. It is divided into two sub-groups; the single-unit and multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous system innervates a single cell within a sheet or bundle and the action potential is propagated by...
of the airway
Airway
The pulmonary airway comprises those parts of the respiratory system through which air flows, conceptually beginning at the nose and mouth, and terminating in the alveoli...
s, leads to airway constriction similar to that seen in asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
. Inhibition of beta-1 receptors in the juxtaglomerular apparatus
Juxtaglomerular apparatus
The juxtaglomerular apparatus is a microscopic structure in the kidney, which regulates the function of each nephron. The juxtaglomerular apparatus is named for its proximity to the glomerulus: it is found between the vascular pole of the renal corpuscle and the returning distal convoluted tubule...
of the kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
inhibits the renin-angiotensin system
Renin-angiotensin system
The renin-angiotensin system or the renin-angiotensin-aldosterone system is a hormone system that regulates blood pressure and water balance....
, causing a decrease in vasoconstriction
Vasoconstriction
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in...
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
Atrioventricular node
The atrioventricular node is a part of the electrical control system of the heart that coordinates heart rate. It electrically connects atrial and ventricular chambers...
conduction and decreases sinus
Sinoatrial node
The sinoatrial node is the impulse-generating tissue located in the right atrium of the heart, and thus the generator of normal sinus rhythm. It is a group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava...
rate.
Nadolol may also increase plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
triglyceride
Triglyceride
A triglyceride is an ester derived from glycerol and three fatty acids. There are many triglycerides, depending on the oil source, some are highly unsaturated, some less so....
s and decrease HDL
High density lipoprotein
High-density lipoprotein is one of the five major groups of lipoproteins, which, in order of sizes, largest to smallest, are chylomicrons, VLDL, IDL, LDL, and HDL, which enable lipids like cholesterol and triglycerides to be transported within the water-based bloodstream...
-cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
levels.
Indications
Nadolol has U.S. Food and Drug AdministrationFood and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
approved indications for the treatment of hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
and for the long-term treatment of angina pectoris.
Off-label uses
Nadolol is used for the prevention of migraine headaches for which there is good documentation.A case report study from Harvard Medical School, published in 1991, described three adult patients with ADHD unsuccessfully treated with traditional psychostimulant (amphetamine) therapy due to lack of effectiveness or intolerance of the psychostimulant. Nadolol was then added to the psychostimulant therapy and the combination of medications resulted in improved attention and focus with decreased medication side effects. This suggested the combination of nadolol and the psychostimulant might be effective for treatment-resistant adults with ADHD.http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1940895&dopt=AbstractContraindications
Patients whose heart rate is largely mediated by the sympathetic nervous systemSympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
(e.g. patients with congestive heart failure
Congestive heart failure
Heart failure often called congestive heart failure is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition...
or myocardial infarct
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
) should avoid nadolol as it inhibits sympathetic function. Nadolol is also contraindicated in patients with bradycardia
Bradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
(slow heart rate) because of its vasodilatory effects and tendency to cause bradycardia.
Because of its beta-2 activity, nadolol causes pulmonary bronchoconstriction and should be avoided in asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
patients in preference of a beta-1 blocker
Beta blocker
Beta blockers or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists or beta antagonists, are a class of drugs used for various indications. They are particularly for the management of cardiac arrhythmias, cardioprotection after myocardial infarction ,...
. (There may be new evidence indicating that long-term non-selective beta-blocker use may actually prove to be beneficial in mild asthma.)
As nadolol, like other beta-2 blockers, inhibits the synthesis and release of glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
in response to hypoglycemia
Hypoglycemia
Hypoglycemia or hypoglycæmia is the medical term for a state produced by a lower than normal level of blood glucose. The term literally means "under-sweet blood"...
, it slows patients' recovery from acute hypoglycemic episodes and should be avoided in patients getting treatment for their diabetes mellitus. In patients with insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
-dependent diabetes, a selective beta-1 blocker is preferred over non-selective blockers.
External links
- Nadolol, from the University of UtahUniversity of UtahThe University of Utah, also known as the U or the U of U, is a public, coeducational research university in Salt Lake City, Utah, United States. The university was established in 1850 as the University of Deseret by the General Assembly of the provisional State of Deseret, making it Utah's oldest...
School of Medicine