18.3 Treatments and Nutrition
3 min read•june 18, 2024
Sodium channel blockers are vital antidysrhythmic drugs that regulate heart rhythms by slowing conduction and prolonging refractory periods. These Class I medications are subdivided based on their effects on action potential duration, targeting various cardiac arrhythmias.
Nurses must understand the indications, adverse reactions, and drug interactions of sodium channel blockers. Careful monitoring, patient education, and collaboration with the healthcare team are crucial for safe and effective management of these powerful cardiac medications.
Class I: Sodium Channel Blockers
Characteristics of Class I sodium channel blockers
Top images from around the web for Characteristics of Class I sodium channel blockers
Electrocardiogram - wikidoc View original
Is this image relevant?
Canales de sodio Nav1.5 cardíacos, regulación e implicaciones clínicas | Revista de la Facultad ... View original
Is this image relevant?
Cardiac action potential - Wikipedia View original
Is this image relevant?
Electrocardiogram - wikidoc View original
Is this image relevant?
Canales de sodio Nav1.5 cardíacos, regulación e implicaciones clínicas | Revista de la Facultad ... View original
Is this image relevant?
1 of 3
Top images from around the web for Characteristics of Class I sodium channel blockers
Electrocardiogram - wikidoc View original
Is this image relevant?
Canales de sodio Nav1.5 cardíacos, regulación e implicaciones clínicas | Revista de la Facultad ... View original
Is this image relevant?
Cardiac action potential - Wikipedia View original
Is this image relevant?
Electrocardiogram - wikidoc View original
Is this image relevant?
Canales de sodio Nav1.5 cardíacos, regulación e implicaciones clínicas | Revista de la Facultad ... View original
Is this image relevant?
1 of 3
- Class I antidysrhythmic drugs block sodium channels in cardiac cells
- Sodium channels enable rapid depolarization (Phase 0) of the cardiac action potential
- Blocking sodium channels slows conduction velocity and prolongs the refractory period (time when cardiac cells cannot be re-excited)
- Class I drugs are subdivided based on their effects on action potential duration (APD)
- Class IA drugs moderately block sodium channels and prolong APD (quinidine, procainamide)
- Class IB drugs mildly block sodium channels and shorten APD (lidocaine, mexiletine)
- Class IC drugs strongly block sodium channels with minimal effect on APD (flecainide, propafenone)
- Slowing conduction velocity and prolonging the refractory period suppresses ectopic foci and reentrant circuits, common mechanisms of dysrhythmias
Cardiac Electrophysiology and Class I Antidysrhythmics
- The cardiac action potential consists of depolarization (sodium influx) and repolarization (potassium efflux) phases
- Class I drugs primarily affect the depolarization phase by blocking sodium channels
- These medications can influence the refractory period, impacting the heart's ability to generate new action potentials
- By modifying cardiac electrophysiology, Class I drugs can suppress abnormal rhythms originating from ectopic foci or reentrant circuits
Indications and reactions of antidysrhythmic drugs
- Indications
- Ventricular tachycardia and fibrillation (abnormally fast heart rhythms originating in the ventricles)
- Supraventricular tachycardias (abnormally fast heart rhythms originating above the ventricles) (atrial fibrillation, atrial flutter)
- Premature ventricular contractions (PVCs) (early heartbeats originating in the ventricles)
- Adverse reactions
- Proarrhythmic effects (paradoxical worsening of dysrhythmias)
- Hypotension (low blood pressure) and negative inotropic effects (decreased heart contractility) due to cardiodepression
- Neurological symptoms (dizziness, confusion, tremors)
- Gastrointestinal disturbances (nausea, vomiting, diarrhea)
- Drug interactions
- Additive QT prolongation with other QT-prolonging medications (certain antibiotics, antipsychotics) increases risk of torsades de pointes (a type of ventricular tachycardia)
- Increased risk of toxicity with drugs that inhibit hepatic metabolism (cimetidine, certain antifungals) by reducing drug clearance
- Enhanced negative inotropic effects when combined with other cardiodepressant drugs (beta-blockers, calcium channel blockers)
Nursing considerations for sodium channel blockers
- Assess baseline cardiac function and rhythm using ECG, vital signs, and physical examination
- Monitor for signs of drug toxicity or proarrhythmic effects
- ECG changes (QRS widening, QT prolongation, new dysrhythmias)
- Hemodynamic instability (hypotension, bradycardia)
- Neurological symptoms (dizziness, confusion, tremors)
- Adjust dosage based on renal and hepatic function, as many Class I drugs are metabolized by the liver and excreted by the kidneys
- Administer medications as prescribed, ensuring proper dose, route, and timing
- Have emergency equipment readily available, including defibrillator and resuscitation medications
- Collaborate with the healthcare team to optimize therapy and manage potential complications
Patient education for Class I antidysrhythmics
- Emphasize the importance of taking medications as prescribed and not abruptly discontinuing therapy without consulting the healthcare provider
- Instruct patients to report any new or worsening symptoms (palpitations, dizziness, fainting)
- Advise patients to inform all healthcare providers about their antidysrhythmic medication use, especially before undergoing surgical or dental procedures
- Educate patients about potential drug interactions and the need to consult their healthcare provider before taking any new medications (over-the-counter products, herbal supplements)
- Encourage patients to maintain a heart-healthy lifestyle
- Regular exercise
- Balanced diet
- Stress management
- Avoidance of tobacco and excessive alcohol consumption
- Provide written educational materials and resources for additional information and support
Key Terms to Review (40)
Aluminum-Containing Antacids: Aluminum-containing antacids are a class of medications used to neutralize stomach acid and provide relief from acid-related conditions such as heartburn, indigestion, and acid reflux. These antacids contain aluminum compounds as the active ingredient, which work by reacting with and reducing the acidity in the stomach.
Amoxicillin- Clavulanate: Amoxicillin-Clavulanate is a combination antibiotic consisting of amoxicillin and clavulanate potassium. It is used to treat various bacterial infections by inhibiting the growth of bacteria and preventing resistance mechanisms.
Anemia: Anemia is a condition characterized by a reduced number or impaired function of red blood cells, leading to a decrease in the oxygen-carrying capacity of the blood. This can have significant implications for an individual's overall health and wellness, particularly in the context of nursing practice and the management of various medical conditions.
Azathioprine: Azathioprine is an immunosuppressive medication commonly used to treat autoimmune diseases and prevent organ rejection after transplants. It works by inhibiting the proliferation of certain cells in the immune system, reducing inflammation and immune responses.
Balsalazide: Balsalazide is a medication primarily used to treat mild to moderate ulcerative colitis. It works by reducing inflammation in the colon and rectum, helping to alleviate symptoms like diarrhea and abdominal pain.
Calcium-Containing Antacids: Calcium-containing antacids are a class of over-the-counter medications used to relieve symptoms of acid reflux, heartburn, and indigestion. They work by neutralizing excess stomach acid, providing temporary relief from these common gastrointestinal issues.
Ciprofloxacin: Ciprofloxacin is a broad-spectrum antibiotic commonly used to treat various bacterial infections, including those affecting the gastrointestinal tract. It works by inhibiting bacterial DNA synthesis, effectively killing the bacteria and preventing their spread.
Clarithromycin: Clarithromycin is a macrolide antibiotic used to treat a variety of bacterial infections. It works by inhibiting bacterial protein synthesis, preventing the bacteria from growing and multiplying. Clarithromycin is commonly prescribed for respiratory, skin, and gastrointestinal infections, and is also used in combination therapy for the eradication of Helicobacter pylori, a bacterium that can cause peptic ulcers.
Crohn’s disease: Crohn’s disease is a chronic inflammatory bowel disease that affects the lining of the digestive tract, potentially causing severe digestive issues. It can lead to abdominal pain, diarrhea, weight loss, and malnutrition.
Dietary Fiber: Dietary fiber refers to the indigestible parts of plant-based foods that pass through the human digestive system without being broken down or absorbed. It is an essential component of a healthy diet, providing numerous benefits for various bodily systems and functions.
Drug–food interactions: Drug–food interactions occur when the food you eat affects the ingredients in a medication you are taking, impacting how the drug works or its side effects. These interactions can either enhance or inhibit the effectiveness of the medication.
Electrolyte Balance: Electrolyte balance refers to the proper regulation and maintenance of essential electrolytes, such as sodium, potassium, chloride, and calcium, within the body's fluids. This delicate balance is crucial for various physiological processes, including nerve and muscle function, fluid balance, and pH regulation.
Enteral Nutrition: Enteral nutrition refers to the delivery of nutrients directly into the gastrointestinal tract, typically through a feeding tube. It is a method of providing nourishment to individuals who are unable to meet their nutritional needs through oral intake alone.
Fat-Soluble Vitamins: Fat-soluble vitamins are a group of essential nutrients that are stored in the body\'s fatty tissues and liver. These vitamins require fat for absorption and transportation, and they play crucial roles in various physiological processes related to fats, vitamins, and treatments.
Gastric Acid: Gastric acid is a digestive fluid produced in the stomach that is essential for the breakdown and digestion of food. It is a key component of the gastric juice and plays a crucial role in maintaining gastrointestinal wellness and facilitating various treatments related to the digestive system.
Gut Microbiota: The gut microbiota refers to the diverse community of microorganisms, including bacteria, archaea, viruses, and fungi, that reside in the human gastrointestinal tract. These microbes play a crucial role in maintaining gastrointestinal wellness and overall health across the lifespan, as well as influencing the efficacy of various treatments and nutritional interventions.
H. pylori: H. pylori, or Helicobacter pylori, is a spiral-shaped bacterium that colonizes the human stomach and is a major cause of peptic ulcers and chronic gastritis. It is closely linked to the function of the digestive organs and is a key consideration in the treatment and nutritional management of related conditions.
H2 Receptor Antagonists: H2 receptor antagonists are a class of medications that work by blocking the action of histamine at the H2 receptors, primarily in the stomach. This inhibits the production of gastric acid, providing relief for conditions related to excessive stomach acid, such as peptic ulcers and gastroesophageal reflux disease (GERD).
Hypermagnesemia: Hypermagnesemia is a condition characterized by an abnormally high level of magnesium in the blood. It can occur due to excessive magnesium intake, reduced excretion, or underlying medical conditions that affect magnesium homeostasis. This term is particularly relevant in the context of treatments and nutrition, as it is important to understand the causes, symptoms, and management of this electrolyte imbalance.
Intramuscular Injections: Intramuscular injections (IM) are a method of administering medications or vaccines by injecting them directly into the muscle tissue. This route of administration allows for rapid absorption and distribution of the substance throughout the body, making it an effective way to deliver certain drugs and immunizations.
Magnesium-Containing Antacids: Magnesium-containing antacids are a class of over-the-counter medications used to relieve symptoms of acid reflux, heartburn, and indigestion. These antacids work by neutralizing excess stomach acid through the inclusion of magnesium compounds, which help to balance the pH levels in the digestive tract.
Mercaptopurine: Mercaptopurine is an immunosuppressive medication used primarily to treat leukemia and inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis. It works by inhibiting the synthesis of DNA, RNA, and proteins in rapidly dividing cells.
Mesalamine: Mesalamine is an anti-inflammatory medication used to treat inflammatory bowel diseases such as ulcerative colitis. It works by reducing inflammation in the colon, thus alleviating symptoms like diarrhea and abdominal pain.
Metronidazole: Metronidazole is an antibiotic and antiprotozoal medication commonly used to treat infections of the gastrointestinal tract. It is particularly effective against anaerobic bacteria and certain parasites.
Moxifloxacin: Moxifloxacin is a broad-spectrum antibiotic commonly used to treat various bacterial infections. It is particularly effective against respiratory, skin, and intra-abdominal infections.
Moxifloxacin and Ciprofloxacin: Moxifloxacin and Ciprofloxacin are broad-spectrum antibiotics belonging to the fluoroquinolone class. They are commonly used to treat various bacterial infections, including those affecting the gastrointestinal tract.
Natto: Natto is a traditional Japanese food made from fermented soybeans. It is known for its unique flavor, aroma, and sticky, stringy texture, which is the result of the fermentation process.
Natto is particularly relevant in the context of treatments and nutrition, as it contains beneficial probiotics and enzymes that can have positive impacts on digestive and overall health.
Nutrient Absorption: Nutrient absorption is the process by which the body takes in and utilizes the essential nutrients from the food we consume. It involves the complex mechanisms within the gastrointestinal system that facilitate the transport of macronutrients, micronutrients, and other compounds from the digestive tract into the bloodstream for distribution and use throughout the body.
Nutritional deficiencies: Nutritional deficiencies occur when the body doesn't get enough essential nutrients from food, leading to various health issues. These deficiencies can significantly impact gastrointestinal health and overall bodily functions.
Olsalazine: Olsalazine is a medication used to treat inflammatory bowel diseases such as ulcerative colitis. It works by reducing inflammation in the colon and rectum, helping to maintain remission of symptoms.
Osteoporosis: Osteoporosis is a chronic, progressive skeletal disorder characterized by a decrease in bone mass and deterioration of bone tissue, leading to an increased risk of fractures. This condition is closely linked to various aspects of nutrition, including protein, vitamins, minerals, and supplements, as well as its impact on the musculoskeletal and integumentary systems across the lifespan.
Parenteral Nutrition: Parenteral nutrition refers to the intravenous administration of nutrients, including carbohydrates, proteins, lipids, vitamins, and minerals, to individuals who are unable to meet their nutritional needs through oral or enteral (tube) feeding. This method of nutrition delivery bypasses the gastrointestinal tract, providing essential nutrients directly into the bloodstream to support various aspects of health, including hematologic, pulmonary, and gastrointestinal wellness.
PPIs: PPIs, or Proton Pump Inhibitors, are a class of medications that work by reducing the production of stomach acid. They are commonly used to treat conditions such as gastroesophageal reflux disease (GERD), peptic ulcers, and other acid-related disorders.
Probiotics: Probiotics are live microorganisms, primarily bacteria, that when consumed in adequate amounts, provide health benefits to the host. They are often referred to as the 'good' or 'friendly' bacteria that reside in the human gastrointestinal tract and play a crucial role in maintaining gut health and overall well-being.
Quinoa: Quinoa is a small, edible seed that is often referred to as a 'superfood' due to its exceptional nutritional profile. It is a gluten-free, high-protein grain that is rich in fiber, vitamins, and minerals. Quinoa is particularly relevant in the contexts of protein nutrition, endocrine wellness, and nutritional treatments.
Rickets: Rickets is a condition caused by a deficiency of vitamin D, calcium, or phosphate, resulting in impaired bone mineralization and growth in children. It is characterized by soft, weak, and deformed bones.
Sulfamethoxazole-Trimethoprim: Sulfamethoxazole-Trimethoprim is a combination antibiotic used to treat a variety of bacterial infections. It is particularly effective against gastrointestinal infections and urinary tract infections.
Sulfasalazine: Sulfasalazine is a medication used to treat inflammatory bowel diseases like ulcerative colitis and Crohn's disease. It combines an anti-inflammatory agent with an antibiotic to reduce inflammation in the gut.
Vitamin B12: Vitamin B12, also known as cobalamin, is an essential nutrient that plays a crucial role in various bodily functions, including the proper functioning of the nervous system, the formation of red blood cells, and the maintenance of DNA. It is a water-soluble vitamin that must be obtained from dietary sources or supplements.
Vitamin K: Vitamin K is a fat-soluble vitamin that plays a crucial role in blood clotting, bone health, and various other physiological processes. It is essential for the proper functioning of the body and is involved in several topics covered in the course, including nutrition, vitamins, supplements, hematological wellness, and the impact of nutrition on the musculoskeletal and integumentary systems.