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Prepared by: Dr Rasol M Hasan Anti- HYPERTENSIVE Drugs ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Vasodilators Examples: Clonidine Methyldopa Hexamethonium Guanithidine, reserpine, alpha blockers Amyl nitrate Hydralazine (oral) Minoxidil(parenteral) Nesiritide Fenoldopam Na nitroprusside Diazoxide Calicium ch. Blockers ACEI, Angio.recep.blockers ACE Inhibitors Sympatholytics Vasodilators CENTRALLY ACTING ALPHA2AGONISTS CLONIDINE,METHYLDOPA Diuretics Ca Channel Blockers Sympatholytics • decreases the sympathetic response from brainstem to peripheral vessels • Stimulate alpha2 receptors: increase vagus activity, decrease cardiac output and decreases serum epinephrine, norepinephrine & renin release • results into reduced peripheral vascular resistance Side effects: Angiotensin Receptor Blockers - drowsiness, dry mouth and nasal mucosa, dizziness, orthostatic hypotension impotence , sodium and fluid retention. ACE Inhibitors ACE Inhibitors Vasodilators - Angiotensin Antagonists (AngiotensinConverting Enzyme [ACE] Inhibitors) Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Action: - Inhibits ACE which in turn inhibits formation of angiotensin II (vasoconstrictor) and blocks the release of aldosterone Side effects: - Constant irritation cough; Nausea; Vomiting; Diarrhea; Fatigue; Hyperkalemia; Tachycardia ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers ACE Inhibitors Indication: - Hypertension (control blood pressure); Prevention of cardiovascular disorders; Preventing kidney damage in people with hypertension or diabetes; Congestive heart failure (CHF); Left ventricular dysfunction Contraindication: - Pregnancy (Lowers placental blood flow); Hypotension ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Vasodilators - Direct Acting Arteriolar Vasodilators eg hydralazine old vasodilator mainly arteriolar dilator Action: - act as blood vessel dilators - relaxes vascular smooth muscles which decrease peripheral vascular resistance and therefore reduces blood pressure Uses of Vasodilators: Systemic and Pulmonary Hypertension Heart Failure Angina ACE Inhibitors Vasodilators Side Effects: Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers CNS: Headache; Peripheral neuropathy; Dizziness CVS: Palpitation; Flushing; Reflex tachycardia; Angina; Ischemic arrhythmias GIT: Nausea; Anorexia Skin: Sweating; Lupus erythematosus like syndrome characterized by: Myalgia, Arthralgia, Skin rashes, Fever Renal: Edema hypotension ECG changes Drowsiness Dry mouth Fatigue ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Vasodilators Contraindications: ischemic heart disease Lupus erythematosus acute MI DM tachycardia thyrotoxicosis Precautions: - caution should be used in uncompensated heart disease or peptic ulcer disease ACE Inhibitors Vasodilators Diuretics Vasodilators Pharmacokinetics: - onset, peak, and duration vary widely among products. Most products are metabolized in the liver and excreted in urine Interactions: Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers - varies widely among products Example of PHARMACOKINETICS OF ` HYDRALAZINE Oral vasodilator but can be given I/V Rapidly metabolized by the liver during first pass bioavailability is low averaging 25% variable among individuals. Well absorbed. ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Ca Channel Blockers 3 CHEMICAL CLASSES: Phenylalkylamines – Verapamil (Calan, Isoptin, Verelan) Benzothiazepines – Diltiazem (C ardizem, Dilacor, Tiazac) Dihydropyridines – Amlodipine (Norvasc), Felodipine (Plendil), Nicardipine (Cardene), Nifedipine (Adalat, Procardia) Mechanism of action: Sympatholytics Angiotensin Receptor Blockers Prevents calcium from entering the excitation-contraction process therefore, prevents muscle contraction and, instead, promotes relaxation of the smooth muscles that surrounds the coronary arteries and causes them to dilate. Ca Channel Blockers ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Indications: Angina Hypertension Supraventricular tachycardia For short-term management of atrial fibrillation and flutter, migraine Headaches. Contraindications: Drug allergy Acute MI Second- or third-degree atrioventricular block Hypotension ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Ca Channel Blockers Adverse Effects: Hypotension Palpitations Tachycardia or bradycardia Nausea Constipation Dyspnea Flushing Peripheral edema Common Drug Interactions Sympatholytics Angiotensin Receptor Blockers • Beta-Blockers • Digoxin – possible increased digoxin level • H2 blockers – elevated levels of Calcium channel blockers • Grapefruit can reduce the metabolism of Ca channel blockers ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics 5 groups of drugs: 1. 2. 3. 4. Beta-adrenergic blockers Centrally acting alpha2-agonists Alpha-adrenergic blockers Adrenergic neuron blockers (Peripherally acting sympatholytics) 5. Alpha1 and Beta1 adrenergic blockers Sympatholytics:[anti-adrenergic] Sympatholytics Angiotensin Receptor Blockers - reduces the physiological effects caused by stimulation of the sympathetic nervous system ACE Inhibitors Sympatholytics Vasodilators BETA-ADRENERGIC BLOCKERS (Beta-blockers) Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Step 1- antihypertensive drugs Step 2 - in combination with diuretics - also used as antianginals and antidysrhythmics - reduces cardiac output by blocking the SympathNS response thus decreasing basal sympathetic tone - continued use: reduces vascular resistance and lowers BP - reduces HR, contractility and renin release - can cross the placental barrier and enter breast milk ACE Inhibitors Sympatholytics Vasodilators BETA-ADRENERGIC BLOCKERS (Beta-blockers) Types: Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers 1. Nonselective • inhibits beta1 (heart) and beta2 (bronchial) receptors • decrease BP secondary to decrease and bronchoconstriction occurs 2. Cardioselective • act mainly on beta1; bronchoconstriction less likely to occur Oral Beta-blockers • Onset of action: 30 mins. or less • Duration: 6 to 12 hours ACE Inhibitors Sympatholytics Vasodilators BETA-ADRENERGIC BLOCKERS (Beta-blockers) Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers IV Beta-blockers • Onset of action: immediate • Peak: 20 mins. • Duration: 4 to 10 hours Side Effects: - dizziness, weakness, wheezes, shortness of breath, Adverse Reactions: - Bradycardia, bronchospasms, markedly decrease BP ACE Inhibitors Sympatholytics Vasodilators BETA-ADRENERGIC BLOCKERS (Beta-blockers) Precaution: Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Should not be used by clients with 2nd- or 3rddegree AV block or sinus bradycardia. Noncardioselective beta-blocker should not be given in patients with COPD Inform patients that herbs can interfere with beta-blockers Example of drugs: Propanolol Metoprolol Acebutolol Atenolol Bisoprolol ACE Inhibitors Sympatholytics Vasodilators CENTRALLY ACTING ALPHA2AGONISTS Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Adverse reactions: - Peripheral edema Example of drugs: Clonidine Methyldopa ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics ALPHA-ADRENERGIC BLOCKERS • blocks alpha-adrenergic receptors which results in vasodilation and decrease BP • maintains renal blood flow rate • useful in clients with lipid abnormalities • safe for diabetic patients because it does not affect glucose metabolism Side effects: Sympatholytics Angiotensin Receptor Blockers - dizziness, headache, vomiting, nausea, drowsiness, and nasal congestion, dry mouth ACE Inhibitors Vasodilators Sympatholytics ALPHA-ADRENERGIC BLOCKERS Adverse reactions: Diuretics - orthostatic hypotension Example of drugs: Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Prazosin Terazosin Doxazosin Phentolamine ACE Inhibitors Vasodilators Sympatholytics ADRENERGIC NEURON BLOCKERS • blocks norepinephrine release, thus lowers BP Diuretics Ca Channel Blockers Sympatholytics • decreases cardiac output and peripheral vascular resistance Side effects: - dizziness, weakness, nausea, drowsiness Adverse reactions: - Orthostatic hypotension, peripheral edema Example of drugs: Angiotensin Receptor Blockers Reserpine Guanethidine ACE Inhibitors Sympatholytics Vasodilators ALPHA1 AND BETA1 ADRENERGIC BLOCKERS Diuretics •blocking alpha1 receptor results in dilation of the arterioles and veins. • decreases BP and moderately decreased PR Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Side effects: -dizziness, weakness, nausea and vomiting, nervousness, dry mouth and fatigue Adverse reactions: - Orthostatic hypotension Example of drugs: Labetalol ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Angiotensin Receptor Blockers Indications: • Hypertension, alone or when in combination with other anti-hypertensive drugs. • Nephropathy in type II DM • Heart failure in those intolerant to ACE inhibitors • Reduce risk of stroke Contraindications and Special Considerations • Drug Allergy • Pregnancy and lactation • Elderly patients • Patients with renal dysfunction ACE Inhibitors Vasodilators Diuretics Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Angiotensin Receptor Blockers Examples: Losartan (Cozaar) Eprosartan (Teveten) Valsartan (Diovan) Irbesartan (Avapo) Candesartan (Atacand) Olmesartan (Benicar) Telmisartan (Micardis) ACE Inhibitors Vasodilators Diuretics Angiotensin Receptor Blockers Serious Side Effects: Altered Liver Function Kidney Impairment Hyperkalemia Orthostatic hypotension Toxicity and Management Ca Channel Blockers Sympatholytics Angiotensin Receptor Blockers Overdose may manifest: • Hypotension • Tachycardia, bradycardia occurs less often treatment is symptomatic and supportive. It includes the administration of IVFs to expand the blood volume Drug to Drug Interaction - can interact with cimetidine, Phenobarbital, and rifampin.