CARDIOVASCULAR MEDICATION
ACE Inhibitors and ARBs
Definition and Purpose
ACE as in Angiotensin-Converting Enzyme inhibitors and ARBs as in Angiotensin Receptor Blockers.
Both are designed to lower blood pressure, not heart rate.
First Choice: ACE Inhibitors
End in -pril (e.g., Lisinopril).
Mnemonic: "chill-pril" for the heart represents that it lowers blood pressure.
Second Choice: ARBs
End in -sartan (e.g., Losartan).
Mnemonic: “sartan” relates to a relaxed or retirement plan, indicating it lowers blood pressure.
Key Questions
Do we administer prills and sartans with bradycardia (heart rate < 60)?
Yes, they lower blood pressure only.
The only indication for holding is low blood pressure, not heart rate.
Mechanism of Action
Function: Both ACE inhibitors and ARBs inhibit or block the RAS (Renin-Angiotensin-Aldosterone System).
Prevents fluid retention by blocking aldosterone, which retains sodium (water) and excretes potassium.
Side Effects:
Hyperkalemia (retaining potassium).
Significantly increase risk of potassium retention in patients.
Side Effects of ACE Inhibitors
Key Memory Aids:
A: Avoid in pregnant patients (teratogenic effects).
A: Angioedema (swelling of face and tongue leading to airway risk - specific to ACE inhibitors).
C: Cough, only associated with ACE inhibitors.
E: Elevated potassium levels (hyperkalemia) - concern when > 5.0 mEq/L.
Comparison: Sartans do not cause cough and spare potassium.
Patient Education
Foods to Avoid: Potassium-rich foods and substitutes such as:
Green leafy vegetables, avocados, melons, oranges, liver.
Signs of Hyperkalemia:
Muscle spasms and changes on ECG (peaked T waves and ST elevations).
Nurse's Role: Always monitor cardiac status for patients on these medications.
General Notes for Nursing Exams
Remember the "three A's":
A for Antihypertensive (not for heart rate).
A for Avoid in pregnancy (not baby safe).
A for Adds potassium (hyperkalemia).
Beta Blockers
Function: Lower heart rate and blood pressure. Commonly ending in -lol (e.g., Atenolol).
Mnemonic: "Double L's" means double lows (heart rate and blood pressure).
Mechanisms and Effects
Negative Chronotropic Effect: Slows the heart rate.
Negative Inotropic Effect: Decreases force of contraction.
** Negative Dromotropic Effect**: Slows conduction (less beats).
Pharmacological Mechanism: Block beta receptors in the sympathetic nervous system:
Beta 1 affects heart; Beta 2 affects lungs.
Non-selective agents block both, leading to bronchospasms (e.g., in asthma/COPD).
Key Considerations
Monitoring: Check heart rate and blood pressure before administration; Hold if:
Heart rate < 60 bpm
Blood pressure < 90/100 systolic.
Potential Side Effects (4 B's):
Bradycardia & Low BP (assess values).
Breathing Problems (wet wheezing in lungs, contraindicated in asthma patients).
Bad for heart failure patients (can worsen symptoms).
Blood sugar masking in diabetics (low alerts).
Calcium Channel Blockers
Function: Lower both blood pressure and heart rate.
Common endings: -dipine, -zem, -mil (e.g., Diltiazem).
Mnemonics: "d pine declines" blood pressure, "zen yoga" calms the heart.
Mechanisms of Action
How They Work: Block calcium movement, leading to:
Relaxation of vascular smooth muscle.
Decreased vascular resistance (less strain on heart).
Nursing Considerations for CCBs
Checking Pre-Administration: Measure heart rate and blood pressure.
Hold if BP < 90/100 systolic or HR < 60 bpm.
Preventing Side Effects: Educate on slow position changes to mitigate orthostatic hypotension.
Side Effects:
Common adverse effect: headaches.
Key Test Questions for Pharmacology
What are the main vital signs to monitor before administering antihypertensives?
Identify signs that necessitate holding medications such as beta-blockers and calcium channel blockers (HR < 60 or BP drop).
Highlight potential adverse reactions and situations when patients should not receive these medications, for instance, in heart failure or respiratory distress.