Antihypertensives Flashcards
what is increased cardiac output in blood pressure?
- Increased fluid volume, excess sodium intake & sodium renal retention
- Excess stimulation of the RAAS (Renin-Angiotensin-Aldosterone System)
- Over-activity of the SNS
what are some factors influencing blood pressure?
- Increased cardiac output
* Increased peripheral resistance
what increased peripheral resistance?
- excess stimulation of the RAAS
- Over-activity of the SNS
- Genetic alterations in cell membranes, e.g. increased intracellular Na/Ca which alters vascular smooth muscle tone.
What are the blood pressure goals?
- treat to BP < 140/90 in most patients
- treat to BP < 130/80 in pts with diabetes or chronic kidney disease, MI, angina, stroke.
- treat to BP < 125/75 in patients with proteinuria
- treat to BP , 140/90 for isolated systolic HTN also. For patients with SBP > 180, the first goal is to reduce SBP to <160. Monitor closely for hypotension: dizziness, sweating, tachycardia, falls, fatigue, etc. Then attempt to reduce BP to the target goal as long as the patient tolerates this reduction.
what are some cardiovascular risks and blood pressure?
- HTN increased the risk of stroke, transient ischemic attacks, dementia, retinopathy, myocardial infarction (MI), angina, heart failure, left ventricular hypertrophy, chronic kidney disease (esp. African American, Hispanic, & Native American), peripheral arterial disease, and early death from a cardiovascular cause.
- Starting at BP of 115/75, risk of CV disease doubles with every 20/10 increase.
- SBP is a stronger predictor of CV disease than DBP
- Isolated systolic HTN may result from pathophysiologic changes in arterial vasculature consistent with aging. These changes decrease the compliance of the arterial wall.
- Pulse pressure (SSBP-DBP) may reflect the extent of atherosclerotic disease and measure arterial stiffness. Higher pulse pressure values are correlated with an increased risk of CV mortality
what are some drugs that worsen hypertension?
- corticosteroids
- Oral contraceptives
- NSAIDs and COX-II inhibitors
- oral decongestants
- Erythropoietin
- Some antidepressants
- Cocaine and cocaine withdrawal
- Ephedra, ma huang
- Nicotine and nicotine withdrawal
- Anabolic steroids
- Narcotic/opioid withdrawal
- Amphetamines
What are some complications of HTN?
- eye damage & blindness
- heart failure, MI, angina, CAD
- chronic kidney disease, failure
- stroke (hemorrhagic or ischemic)
- TIA (mini stroke), dementia
what drugs make up alpha 2 adrenergic agonists?
clonidine (Catapres)
methyldopa (Aldomet)
What are alpha 2 adrenergic agonists (clonidine & methyldopa) mechanism of action?
- preferentially stimulates the alpha 2 receptors of the brain stem associated with autonomic regulation of the cardiovascular system. Remember that activation of the alpha 2 receptor will cause neurons to quit releasing norepinephrine. Thus, alpha 2 receptors are inhibitory in nature. this will result in decreased sympathetic output, decreased blood pressure, & decreased heart rate.
- Clonidine comes in a patch form that is changed weekly. This may be a good option for patients with compliance problems.
What are the alpha 2 adrenergic agonists therapeutic uses? (clonidine & methyldopa)
- Main use is treatment of chronic hypertension.
- Clonidine tabs chewed & swallowed are effective for hypertensive urgecies.
- Clonidine has been used in the treatment of withdrawal symptoms of nicotine, opiates, benzodiazepines, & alcohol.
- Methyldopa is a drug of choice in pregnancy induced hypertension.
What are the adverse effects of Alpha 2 Adrenergic Agonists? (Clonidine & methyldopa)
- drowsiness (35%)
- dry mouth (40%)
- constipation
- headache
- impaired ejaculation
- **avoid abrupt withdrawal- will cause severe rebound HTN
What drugs are included in the alpha 1 blockers (antagonists)?
"zosin" drugs doxazosin prazosin Silodosin terazosin tamsulosin alfuzosin
what are the alpha 1 blockers (antagonists) mechanism of action?
- competitive blocking of the alpha 1 receptors
- HTN: lowers blood pressure by causing vasodilation. Relaxes both arterial and venous smooth muscle surrounding some blood vessels.
- BPH: These drugs also relax the smooth muscle of the bladder neck & prostate, which improves urine flow in BPH
what are the alpha 1 blockers (antagonists) therapeutic uses?
- HTN
* urinary retention associated with benign prostatic hyperplasia (BPH), & Raynaud’s disease (vasoconstriction disease)
what are the adverse effects of alpha 1 blockers (antagonists)?
- Orthostatic hypotension (>10%) warn patient about this!!! FIRST DOSE EFFECT- syncope (fainting) following the 1st dose. To minimize falls, instruct patient about orthostatic hypotension, give at bedtime, and initiate therapy with dosage titration. The BPH selective alpha 1 blockers are less likely to cause orthostatic hypotension.
- reflex tachycardia
- dizziness, lack of energy, drowsiness, nasal congestion, headache, decreased libido, and inhibition of ejaculation.
What drugs are included in the First-Generation: Non-selective Beta blockers?
“olol” drugs
- propranolol
- Sotalol
- Timolol
- nadolol
- carteolol
- pindolol
- penbutolol
what are First-Generation: non-selective Beta blockers mechanism of action?
- competitive blocking of the beta 1 & beta 2 receptors
- Cardiovascular effects (beta 1 mediated): decreased hear rate (negative chronotrope); decreased force of contraction (negative inotrope); decreased cardiac workload & oxygen demand.
What are the First-Generation: non-selective Beta blockers therapeutic uses?
- Cardiac: Hypertension, angina, post MI, heart failure, atrial fibrilation, & tachycardia.
- Some, carteolol & timolol, are used as eye drops to treat glaucoma.
- Other: Hyperthyroidism, migraine prophylaxis, essential tremor, stage fright.
