Download to read offline
![Pharmacology_of_HTN_for_midwife[1].pptx](https://cdn.slidesharecdn.com/ss_thumbnails/pharmacologyofhtnformidwife1-230902073731-2edb00cc-thumbnail.jpg?width=640&height=640&fit=bounds)
PHARMACOLOGY ANTIHYPERTENSIVE AGENTS (2).pptx
- 1. ANTIHYPERTENSIVE AGENTS: BY SHEIKHMOHAMED SHUKRI LECTURER KMTC
- 2. CLASSES Angiotensin-Converting Enzymes (ACE) Inhibitors –benazepril (Lotensin) – captopril (Capoten) – enalapril (Vasotec IV) – quinapril (Accupril)
- 3. • Angiotensin II-ReceptorBlockers (ARBs) – irbesartan (Avapro) – losartan (Cozaar) – telmisartan (Micardis) – valsartan (Diovan)
- 4. • Calcium-Channel Blockers –amlodipine (Norvasc) – diltiazem (Diltiazem) – nicardipine (Cardene) – nifedipine (Adalat, Procardia) – verapamil (Calan, Isoptin)
- 5. • Vasodilators – hydralazine(Apresoline) – minoxidil (Loniten) – nitroprusside (Nitropress) • Renin Inhibitors – aliskiren (Tekturna)
- 6. • Alpha-2 Agonist •Clonidine is an Alpha-2 agonist. You can read more information about Alpha-2 agonists in the “Autonomic Nervous System” chapter. Beta-1 Antagonist • Metoprolol is a selective Beta-1 blocker. You can read more information about Beta-1 antagonists in the “Autonomic Nervous System” chapter.
- 7. ACE INHIBITOR ACE Inhibitor(Angiotensin Converting Enzyme) • Captopril is an example of an ACE (angiotensin converting enzyme) inhibitor. • Mechanism of Action • This medication blocks the conversion of Angiotensin I to Angiotensin II in the renin- angiotensin-aldosterone system. This will lead to vasodilation and sodium and water excretion by blocking aldosterone.
- 8. • Indications forUse • Captopril is used to treat hypertension and heart failure. This medication also helps reduce diabetic nephropathy. • Nursing Considerations Across the Lifespan • Do not administer to patients who are pregnant. Use with caution with patients who have diabetes.
- 9. • Avoid usewith other medications that increase potassium. This medication may increase risk for lithium toxicity.
- 10. Black Box Warning: BlackBox Warning: Patients who become pregnant should discontinue this medication due to the risk of fetal harm or fetal death. Patients taking this medication may experience hypotension, cough, hyperkalemia, increased risk for infection, angioedema, anaphylactoid reactions, or proteinuria.
- 11. • Patients whoexperience increased facial swelling or difficulty swallowing or breathing should seek emergency medical attention. Report a persistent cough or angioedema to the health care provide
- 12. SIDEFFECTS SUMMARY • HypotensionCough •Hyperkalemia • Neutropenia or agranulocytosis • Angioedema • Anaphylactoid reactions • Proteinuria
- 13. ANGIOTENSIN II RECEPTORBLOCKER (ARB) • Angiotensin II Receptor Blocker (ARB) • Losartan is an example of an Angiotensin II receptor blocker, also referred to as an ARB. ARBs are similar to ACE inhibitors in that they act on the renin-angiotensin-aldosterone system (RAAS).
- 14. Patient Teaching &Education • Medications should be taken as directed. • Patients taking ACE inhibitors should be cautioned to avoid salt substitutes or foods high in potassium. • Additionally, the medication may alter the sense of taste, but this generally resolves within 2-3 months of medication therapy.
- 15. • However, thedifference is that they block Angiotensin II and cause vasodilation and decreased peripheral resistance, but are not likely to cause the cough that ACE inhibitors can. • Mechanism of Action • Losartan blocks Angiotensin II in the renin- angiotensin-aldosterone system to produce vasodilation.
- 16. Indications for Use •ARB is used for treatment of hypertension and to prevent nephropathy in diabetic patients. Nursing Considerations Across the Lifespan • Do not administer to patients who are pregnant. It is not recommended for children under 6. Anticipate dosage adjustment with hepatic impairment. This drug can cause renal impairment and hyperkalemia.
- 17. Adverse/Side Effects • Adverse/SideEffects • Black Box Warning: Patients who become pregnant should discontinue this medication due to the risk of fetal harm or fetal death. • Patients taking this medication may experience hypotension, dizziness, increased risk for infection, angioedema, or proteinuria.
- 18. • Patients whoexperience increased facial swelling or difficulty swallowing or breathing should seek emergency medical attention. Patient Teaching & Education • Medications should be taken as directed at the same time each day. Patients should not discontinue therapy unless directed to by their healthcare provider.
- 19. • Patients shouldbe careful to avoid salt substitutes and foods with high levels of potassium. ARBs may cause orthostatic changes and patients should be cautioned to change positions slowly • Hypotension and dizziness Hyperkalemia Proteinuria
- 20. Calcium-Channel Blockers • Calcium-channelblockers as antihypertensive agents decrease blood pressure, cardiac workload, and myocardial consumption of oxygen. • Since these drugs can significantly decrease cardiac workload, they are effective in treatment of angina.
- 21. THERAPEUTIC ACTION • Thesedrugs inhibit the movement of calcium ions across myocardial and arterial musclecell membranes. As a result, action potential of these cells are altered and cell contractions are blocked. • Resultant effects include: depressed myocardial contractility, slow cardiac impulse in conductive tissues, and arterial dilation and relaxation.
- 22. INDICATION • Like ACEinhibitors and ARBs, they can also be used alone for treatment of hypertension or in combination with other antihypertensive agents. • Extended-release preparations are usually indicated for hypertensions in adults.
- 23. • Children: calcium-channelblockers is the drug group that is first considered in cases of hypertension in this age group that needs drug therapy. • Adults: these drugs are not allowed during pregnancy
- 24. SIDEEFFECTS Adverse Effects • CNS:headache, dizziness, light- headedness, fatigue • CV: hypotension, bradycardia, peripheral edema, heart block • GI: nausea, hepatic injury • EENT: rash, skin flushing
- 25. Direct vasodilators • Description •Direct vasodilators are used when the previous drugs mentioned are not effective. • These antihypertensive agents are reserved for severe hypertension and hypertensive emergencies.
- 26. • Therapeutic Action •These antihypertensive agents exert their effect by acting directly on smooth muscles. Consequently, there will be muscle relaxation and vasodilation. Both of these will cause drop in blood pressure.
- 27. INDICATIONS • As mentioned,these drugs are only used for hypertension cases that do not respond to other drug therapies. • Nitroprusside is used in maintaining controlled hypotension during surgery. • Nitroprusside is administered intravenously; hydralazine is available for oral, intravenous, and intramuscular use; and minoxidil is available for oral use only.
- 28. • CNS: headache,dizziness, anxiety • CV: reflex tachycardia, heart failure, edema, chest pain • GI: nausea, vomiting, GI upset • EENT: rash, lesions (e.g. minoxidil is associated with abnormal hair growth.) • Nitroprusside is metabolized into cyanide so it can cause cyanide
- 29. Cyanide toxicity characterizedby dyspnea, ataxia, loss of consciousness, distant heart sounds, and dilated pupil. • Nitroprusside suppresses iodine uptake which leads to development of hypothyroidism
- 30. BETA BLOCKERS • Betablockers block the BETA receptors sites in the body so norepinephrine and epinephrine can NOT bind to the receptor site and elicit a sympathetic nervous system response.
- 31. • When BETAreceptors sites are stimulated by the SNS and have norepinephrine and epinephrine bind to them, the person can experience (note these are just some of the responses created by the sympathetic nervous system):
- 32. • Increase heartrate and blood pressure – This increases cardiac output and the workload on the heart, but it requires a lot of oxygen demand by the myocardium. • Increase strength of heart contractions – This helps to increase cardiac output.
- 33. • Bronchodilation – Thebronchioles will dilate so breathing can be easier and more oxygen can enter the blood. Remember this oxygen is needed because the myocardium demands it for this type of nervous system response. • Increase blood sugar for energy via glycogenolysis in the liver.
- 34. • Beta blockerswill block many of these actions, and this can be helpful in certain conditions when the workload of the heart needs to be decreased or the heart is beating too fast (dysrhythmias). • It’s very important to know that there are different types of beta receptors in the body….beta 1, beta 2, and beta 3
- 35. • Beta 1receptors are mainly located in the HEART (remember you have one heart) and in the kidneys (specifically the juxtaglomerular cells that release renin). • Beta 2 receptors are located in the bronchioles of the LUNGS (remember you have two lungs), GI system, vascular smooth muscle and skeletal muscle, and ciliary body of the eye. • Beta 3 receptors are located in the fatty/adipose tissue of the body.
- 36. Types of BetaBlockers Types of Beta Blockers • All generic beta blockers names end in “LOL”. • Selective beta blockers are selective to only beta 1 receptors. These medications are sometimes referred to as cardioselective because they mainly target the heart since it’s mainly made up of beta 1 receptors. • Atenolol, Esmolol, Metoprolol et
- 37. • Nonselective betablockers block BOTH beta 1 and beta 2 receptors. They’re not selective to one certain type of beta receptor. Therefore, they will target the heart and kidneys too, but will also target the GI system, LUNGS, vascular smooth muscle etc. These medications have more of a peripheral effect than the selective beta blockers.
- 38. Mechanism of Actionof Beta Blockers • Slow heart rate (both selective and nonselective)Beta receptors (mainly beta 1) are in the cardiac nodal tissue and conduction system of the heart. These areas control our heart rate. Beta blockers slow down how they work, so they’re helpful with dysrhythmias like supraventricular tachycardia
- 39. • Monitor forAV blocks like 2 or 3 degree and severe bradycardia (contraindicated) • Mask tachycardia during hypoglycemic episodes in diabetics because these medications keep the heart rate from increasing (remember they slow down the heart rate)
- 40. • Decrease thestrength of contractions (both selective and nonselective)Beta receptors (mainly beta 1) are in the cardiac myocytes that control the strength of the heart’s contractions. Beta blockers cause a negative inotropic effect because they make the contractions weaker.
- 41. • This helpsease the workload on the heart and decrease oxygen consumption by the myocardium (great for treating stable angina due to coronary artery disease). • Watch for the development or worsening of heart failure…not to be used in patient with uncompensated heart failure or cardiogenic shock.
- 42. • Lowers bloodpressure (both selective and nonselective)Beta receptors (mainly beta 1) are in the juxtaglomerular cells of the kidneys. Beta blockers will prevent angiotensin II from being created in the RAAS because it inhibits the release of RENIN by the juxtaglomerular cells.
- 43. • Remember angiotensinII normally causes vasoconstrictor, but there will be vasodilation instead and the influence of aldosterone will be decreased (so less water is reabsorbed by the kidneys) and this will decrease blood volume and in turn decrease the blood pressure.
- 44. • Decrease intraocularpressure (only nonselective)The ciliary body of eye has beta 2 receptors. The ciliary body of the eye is responsible for the production of aqueous humor. In patients with glaucoma, the high eye pressure is high due to a high amount of aqueous humor collecting in the eye
- 45. Nonselective beta blockers(example eye drops like Timolol) will decrease the production of aqueous humor and help decrease intraocular pressure
- 46. SIDE EFFECTS, RESPONSIBILITIES,EDUCATION? Bradycardia and blocks….2 or 3 degree heart blocks • monitor EKG and teach patient to monitor heart rate at home for bradycardia Exacerbate heart failure due to negative inotropic effect • monitor for pulmonary edema, swelling in extremities, jugular venous distention, weight gain, I and O’s, daily weights…TEACH patient to monitor self at home
- 47. • Taper off(beta blockers are typically tapered off over 2 weeks or so)… TEACH patient to NEVER just stop taking because the body will have withdrawal issues like rebound hypertension, ischemia that leads to angina etc. • Asthma & COPD patients can’t have nonselective beta blockers due to bronchoconstriction… Propranolol, Sotalol, Timolol etc.
- 48. • Blood glucosemonitored closely in diabetes (TEACH). They need to monitor for hypo/hyperglycemic AND the masking of hypoglycemia due to NO TACHYcardia experienced with blood glucose drops.
- 49. • Low bloodpressure (hypotension)…TEACH patient to monitor blood pressure at home. • Orthostatic hypotension: monitor and teach….slowly changes positions when going from a sitting to lying position to standing
- 50. • Circulation impaireddue to peripheral vasoconstriction (NONselective) • peripheral circulation is circulation to the vessel to the hands, legs, feet, and arms • Erectile dysfunction, cold feet and hands, leg cramps…NOT for patient with peripheral vascular disease
- 51. • Know overdosesigns and symptoms: Bradycardia, heart blocks, low blood pressure, mental status changes: very lethargic or fainting, difficulty breathing due to bronchospasm, heart block… TEACH patient to monitor for these as well.