Beta 2 Receptor Agonists Overview

Beta 2 Receptor Agonists bind to beta 2 receptors on airway smooth muscle cells, causing relaxation and bronchodilation.

Short-acting beta agonists (SABAs) provide relief for 4-6 hours. Examples include albuterol, levalbuterol, pirbuterol, and terbutaline.

Long-acting beta agonists (LABAs) provide relief for 12 hours. Examples include salmeterol, formoterol, and arformoterol.

Ultra-long-acting beta agonists (ULABAs) provide relief for 24 hours. Examples include indacaterol, olodaterol, vilanterol.

Inhaled anticholinergics block muscarinic cholinergic receptors, preventing acetylcholine from causing airway muscle contraction.

Short-acting muscarinic antagonists (SAMAs) provide relief for 4-6 hours. Examples include ipratropium bromide.

Long-acting muscarinic antagonists (LAMAs) provide relief for 12-24 hours. Examples include tiotropium bromide, aclidinium bromide, umeclidinium bromide, and revefenacin.

Methylxanthines, like theophylline, inhibit phosphodiesterases, which leads to an increase in cyclic AMP, resulting in bronchodilation and pulmonary vessel relaxation.

Inhaled corticosteroids (ICS) suppress the inflammatory response in the airway by inhibiting the release of inflammatory mediators.

Leukotriene modifiers work by blocking the action of leukotrienes, inflammatory mediators that contribute to airway inflammation and bronchospasm. Examples include montelukast (Singulair) and zileuton (Zyflo).

Antihistamines block the action of histamine, a chemical that contributes to allergic reactions. Examples include diphenhydramine (Benadryl), cetirizine (Zyrtec), and loratadine (Claritin).

Intranasal antihistamines are used for the treatment of seasonal allergic rhinitis and vasomotor rhinitis. Examples include azelastine (Astelin) and olopatadine (Patanase).

Nasal corticosteroids are used to treat nasal inflammation and congestion. Examples include fluticasone (Flonase), budesonide (Rhinocort), and mometasone (Nasonex).

Decongestants, commonly used in oral or nasal spray forms, relieve nasal congestion by constricting blood vessels in the nasal mucosa. Examples include pseudoephedrine and phenylephrine.

Expectorants are medications that help to loosen mucus in the respiratory tract, making it easier to cough up. They are commonly used to treat coughs associated with colds, bronchitis, and other respiratory conditions.

Expectorants can cause nausea, vomiting and diarrhea. They are not recommended for coughs related to asthma, COPD, heart failure or ACE inhibitor therapy.

Diuretics are medications that increase urine production, leading to a decrease in fluid volume in the body. They are commonly prescribed for high blood pressure and heart failure.

Diuretics are a first-line therapy for high blood pressure and heart failure because they reduce fluid overload and lower blood pressure. This works by reducing cardiac output and peripheral resistance.

Diuretics can cause electrolyte imbalances such as hypokalemia (low potassium), hypercalcemia (high calcium), hyponatremia (low sodium) and hypomagnesemia (low magnesium). These imbalances can lead to various side effects including metabolic alkalosis.

Thiazide diuretics are a class of diuretics that inhibit sodium reabsorption in the distal renal tubule, leading to increased urine production and decreased blood volume.

Loop diuretics work by inhibiting sodium reabsorption in the ascending loop of Henle, leading to rapid and potent diuresis. This class of diuretics is often used for acute conditions.

Aldosterone antagonists, also known as potassium-sparing diuretics, work by blocking the action of aldosterone in the distal tubule of the kidney, leading to increased sodium excretion and potassium retention.

Common loop diuretics include furosemide and bumetanide.

Common thiazide diuretics include chlorthalidone, hydrochlorothiazide, indapamide, and metolazone.

Common aldosterone antagonists include spironolactone, triamterene, amiloride, and eplerenone.

Stimulant laxatives work by irritating the intestinal lining and stimulating peristalsis, the process of muscle contractions that move food through the digestive tract.

Osmotic laxatives work by drawing water into the intestines, softening the stool and increasing its volume, leading to increased peristalsis.

Bulk-forming laxatives work by absorbing water in the intestines, adding bulk to the stool, making it easier to pass. They are often used for long-term constipation management.

H2RAs block the histamine-2 receptors on gastric parietal cells, reducing HCl production and raising gastric fluid pH towards alkalinity. They are often used to treat GERD and PUD.

H2RAs are not anticholinergic because they don't block histamine-1 receptors.

H2RAs have varying effects on gastric secretion volume, hydrogen ion concentration, gastric emptying speed, LES pressure, and serum gastrin levels. Famotidine is the most potent in lowering gastric acid secretion.

H2RAs are not well-studied in pregnancy and lactation, so their use is often avoided. Always weigh the benefits against the risks before prescribing these drugs to pregnant or lactating women.

H2RAs can cause adverse effects like gynecomastia and erectile dysfunction (usually with cimetidine), cardiac rhythm and conduction abnormalities, CNS disturbances, hematologic problems, GI issues, vitamin B12 deficiency, immune-related problems, and fever.

Metoclopramide is a drug used for GERD (lower therapy tiers) and gastroparesis. It has prokinetic properties but does not heal esophageal lesions and can cause EPS (extrapyramidal symptoms) particularly in younger individuals.

Bethanechol is another drug used for lower tiers of GERD therapy and gastroparesis. It has prokinetic properties but does not heal esophageal lesions.

Antacids are used to treat GERD. They improve LES tone and increase gastric pH.

The goals of therapy for PUD are to eliminate H. pylori, reduce or eliminate symptoms, heal ulcer lesions, prevent complications like bleeding and perforation, and prevent recurrence.

PPIs (proton pump inhibitors) are the main antisecretory drugs used to treat PUD. They are more effective at gastric acid suppression than H2RAs.

The main goals of GERD treatment are to manage symptoms, heal esophagitis or esophageal lesions, prevent complications like esophageal cancer, and reduce the recurrence of symptoms.

Nonpharmacologic therapy for GERD involves lifestyle changes like avoiding trigger foods, eating smaller meals, staying upright after meals, elevating the head of the bed, weight loss, and smoking cessation.

Antacids are weak bases that neutralize stomach acid, providing temporary relief from GERD symptoms. They are often used as adjunctive therapy for frequent or occasional symptoms.

Proton pump inhibitors (PPIs) are the first-line treatment for most GERD patients, especially those with frequent symptoms or complications like esophagitis. They effectively suppress stomach acid by blocking the enzyme responsible for acid production.

Histamine-2 (H2) receptor antagonists, like cimetidine, ranitidine, and famotidine, are used to treat GERD, but typically not as first-line therapy. They block histamine from stimulating stomach acid production.

Drugs that improve lower esophageal sphincter (LES) tone are used adjunctively to enhance the barrier between the stomach and esophagus. Examples include baclofen and bethanechol.

Prokinetic agents, like metoclopramide, speed up gastric emptying and increase LES tone. However, their potential for adverse effects limits their use to cases with persistent symptoms despite other treatments.

Cytoprotective agents, such as sucralfate, protect the lining of the stomach from damage. While used in PUD, their role in GERD is limited.

Antacids can cause constipation (aluminum- and calcium-based) or diarrhea (magnesium-based). Other possible side effects include alkalosis (in renal failure patients) and drug interactions.

Antacids are not used alone for significant GERD or frequent symptoms. They should be used in conjunction with an acid suppressive drug. Avoid their use when the cause of gastrointestinal symptoms is unknown.

PPIs effectively suppress gastric acid secretion by inhibiting the enzyme that pumps hydrogen ions into the stomach. This reduction in acid can have additional effects on gastric physiology.

PPIs are generally well-tolerated in the short term. However, long-term use can lead to nutrient deficiencies, bone health issues, kidney problems, increased infection risk, potential for gastric cancer, and possible association with dementia and mortality.

Special considerations for PPI usage include contraindications with hypersensitivity, cautious use in hepatic dysfunction and older adults, avoidance during pregnancy unless benefits outweigh risks, and cautious use during lactation.

H2 receptor antagonists are generally less potent at reducing acid than PPIs. They are used for milder GERD symptoms or as adjunctive therapy.

H2 blockers are generally well tolerated. However, they can cause side effects like headache, dizziness, constipation, and diarrhea.

Antidiarrheals used to treat chronic diarrhea in IBS, specifically targeting mu and kappa opioid receptors, while antagonizing delta opioid receptors. Avoid use in patients with biliary disorders, pancreatitis, liver impairment, and heavy alcohol use.

A selective 5-HT3 receptor antagonist that reduces intestinal motility and secretions, easing symptoms of diarrhea-predominant IBS in women. Used when other therapies haven't worked.

Antihistamines are particularly useful for motion sickness related nausea and vomiting. They work by slowing neuronal communication in the vestibulocerebellar areas.

Antihistamines can cause anticholinergic effects like dry mouth, blurred vision, and constipation. It's important to avoid them in older adults and assess benefit to risk in pregnancy and lactation.

Phenothiazines like prochlorperazine are effective in preventing and treating nausea and vomiting. They block dopamine receptors in the chemoreceptor trigger zone (CTZ), reducing nausea.

Phenothiazines can cause various adverse effects, including extrapyramidal symptoms (EPS), sedation, respiratory depression in children, and agranulocytosis (with prolonged use).

Cannabinoids like dronabinol are used to treat chemotherapy-induced nausea and vomiting when other treatments fail. They act on cannabinoid receptors centrally.

5-HT3 receptor antagonists like ondansetron are used to prevent chemotherapy-induced nausea and vomiting. They block serotonin receptors peripherally and centrally, preventing chemotherapy-induced serotonin release.

Scopolamine, a belladonna alkaloid, is used to prevent motion sickness-induced nausea and vomiting. It acts as an anticholinergic, blocking muscarinic receptors in the parasympathetic nervous system.

Aprepitant is a Substance P/neurokinin 1 (NK1) receptor antagonist used to prevent chemotherapy-induced nausea and vomiting. It works as adjunctive therapy with 5-HT3 receptor antagonists and dexamethasone.

Trimethobenzamide is a miscellaneous antiemetic used to treat nausea and vomiting. It works by blocking dopamine-2 receptors in the CTZ, preventing the central vomiting center from inducing nausea.

Antidiarrheals like loperamide are commonly used to treat chronic diarrhea in IBS. These drugs reduce intestinal motility, slowing the passage of stool through the gut.

Diphenoxylate and difenoxin are effective antidiarrheals that slow intestinal motility. They work by binding to opioid receptors in the gut, but caution should be taken as they have sedative and other anticholinergic effects.

Anticholinergics like scopolamine have anticholinergic effects that can cause dry mouth, blurred vision, constipation, and urinary retention. These effects are more pronounced in older adults.

Anticholinergics like scopolamine can cause mydriasis, which is dilation of the pupils. This can significantly affect vision and make it difficult to perform tasks requiring clear vision. Caution patients to wear sunglasses and avoid driving.

Beta 2 Receptor Agonists are medications that bind to beta 2 receptors on airway smooth muscle cells, causing relaxation and bronchodilation. They are used to treat asthma and COPD.

Beta 2 Receptor Agonists are absorbed from the bronchi, metabolized in the liver, and excreted in the urine.

Short-Acting Beta Agonists (SABAs) provide relief for 4-6 hours and examples include albuterol, levalbuterol, pirbuterol, and terbutaline.

Long-Acting Beta Agonists (LABAs) provide relief for 12 hours and examples include salmeterol, formoterol, and arformoterol.

Ultra-Long-Acting Beta Agonists (ULABAs) provide relief for 24 hours and examples include indacaterol, olodaterol, and vilanterol.

Inhaled anticholinergics block muscarinic cholinergic receptors in the airways, preventing acetylcholine from causing airway muscle contraction. They are used to treat COPD and asthma.

Short-Acting Muscarinic Antagonists (SAMAs) provide relief for 4-6 hours. An example is ipratropium bromide.

Long-Acting Muscarinic Antagonists (LAMAs) provide relief for 12-24 hours and examples include tiotropium bromide, aclidinium bromide, umeclidinium bromide, and revefenacin.

Methylxanthines, like theophylline, inhibit phosphodiesterases, which leads to an increase in cyclic AMP, resulting in bronchodilation and pulmonary vessel relaxation. They are used to treat asthma and COPD.

Inhaled Corticosteroids (ICS) suppress the inflammatory response in the airway by inhibiting the release of inflammatory mediators. They are used for long-term control of asthma and COPD.

Leukotriene Modifiers block the action of leukotrienes, inflammatory mediators that contribute to airway inflammation and bronchospasm. Examples include montelukast (Singulair) and zileuton (Zyflo).

Antihistamines block the action of histamine, a chemical that contributes to allergic reactions. Examples include diphenhydramine (Benadryl), cetirizine (Zyrtec), and loratadine (Claritin).

Intranasal Antihistamines are used for the treatment of seasonal allergic rhinitis and vasomotor rhinitis. Examples include azelastine (Astelin) and olopatadine (Patanase).

Nasal Corticosteroids are used to treat nasal inflammation and congestion. Examples include fluticasone (Flonase), budesonide (Rhinocort), and mometasone (Nasonex).

Decongestants are used to relieve nasal congestion by constricting blood vessels in the nasal mucosa. Examples include pseudoephedrine and phenylephrine.

Expectorants can cause nausea, vomiting, and diarrhea. They are not recommended for coughs related to asthma, COPD, heart failure, or ACE inhibitor therapy.

Histamine-2 Receptor Antagonists (H2RAs) are a class of drugs that block the histamine-2 receptors on gastric parietal cells, reducing hydrochloric acid (HCl) production and increasing gastric fluid pH towards alkalinity.

H2RAs have varying effects on gastric secretion volume, hydrogen ion concentration, gastric emptying speed, lower esophageal sphincter (LES) pressure, and serum gastrin levels. Famotidine is the most potent in lowering gastric acid secretion.

PPIs (proton pump inhibitors) are the main antisecretory drugs used to treat PUD. They are more effective at gastric acid suppression than H2RAs.

These medications are commonly employed to address chronic diarrhea in individuals with Irritable Bowel Syndrome (IBS). They work by slowing down the movement of stool through the digestive tract.

These medications are effective at slowing down intestinal mobility, leading to a decrease in the frequency of bowel movements. However, they shouldn't be used in intestinal infections, as they may worsen the condition.

A selective 5-HT3 receptor antagonist, Alosetron helps decrease intestinal motility and secretions. It is generally a last resort for women with IBS associated with predominantly diarrhea, only when other treatments have failed.

This medication works by stimulating the release of dopamine, which helps reduce nausea and vomiting by blocking dopamine receptors in the chemoreceptor trigger zone (CTZ). However, it's important to use it cautiously, considering its numerous side effects, particularly the risk of extrapyramidal symptoms.

These medications are often used to prevent chemotherapy-induced nausea and vomiting. They work by blocking serotonin receptors in the brain and the digestive system, preventing the release of serotonin by chemotherapy drugs.

This medication is commonly used as a preventive measure for motion sickness. It works by blocking muscarinic receptors in the parasympathetic nervous system, resulting in a reduction of nausea and vomiting symptoms.

A substance P/neurokinin 1 (NK1) receptor antagonist, Aprepitant is often prescribed along with 5-HT3 receptor antagonists and dexamethasone to prevent chemotherapy-induced nausea and vomiting.

Antihistamine drugs, often used to treat motion sickness, are particularly effective in slowing down communication between neurons in the vestibulocerebellar areas, contributing to their efficacy in reducing symptoms like nausea and vomiting.

Cannabinoids are often used to treat nausea and vomiting caused by chemotherapy, especially when other treatments have failed. This is because they work by triggering cannabinoid receptors in the brain.

This medication is used to treat nausea and vomiting by working as an antagonist at dopamine-2 receptors, effectively blocking the action of dopamine in the CTZ. Although not as potent as other drug classes, it is still prescribed.

These medications act by suppressing the inflammatory response in the airways, which can help control both asthma and COPD.

These agents work by blocking the action of leukotrienes, chemical messengers involved in airway inflammation and constriction. This can help manage asthma and COPD.

These medications target beta 2 receptors on airway smooth muscle cells, resulting in relaxation and bronchodilation. This makes them a crucial treatment for asthma and COPD.

These medications work by blocking the action of acetylcholine, which causes airway muscle contraction. They are often prescribed to manage conditions like asthma and COPD.

These medications inhibit phosphodiesterases, an enzyme that breaks down cyclic AMP, leading to an increase in cyclic AMP levels. This contributes to bronchodilation and relaxation of pulmonary