Term
| Role of Calcium Channel Blockers? |
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Definition
| Prevent calcium ions from entering the cells. plays a critical role in the function of vascular smooth muscles (coronary vessels and within the heart) |
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Term
| 3 Role of calcium channel blockers within the heart? |
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Definition
Myocardium (force of contractions)
SA Node (heart rate)
AV Node (conduction of impulse) |
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Term
| Three calcium channel blockers |
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Definition
Dihydropyridines (nifedipine)
verapamil
Diltiazem |
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Term
| Two main direct effects of verapamil |
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Definition
Blocks Calcium channels on VSM (relax of VSM =relaxation)
Blocks Calcium Channels in the myocardium (most effects here. increasing rate force of contraction and) |
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Term
| Where are most of verapamil effects on? |
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Definition
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Term
| What are 3 verapamil effects on the myocardium? |
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Definition
| decreases rate, decreases force of contraction, decreases amount of blood pumped with each contraction. |
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Term
| What are 1 verapamil effects on VSM |
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Definition
| relaxation of VSM, therefore decrease in blood pressure |
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Term
| Indirect effect of Verapamil ( this does not always neutralize the slowing of the heart rate, some people will have slowing of heart rate and significant decrease in heart contraction which can lead to heart failure. Depends on indv. patient and how healthy their heart is) |
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Definition
| By decreasing the blood pressure that comes from the relaxation of vascular smooth muscle in the arteries, the baroreceptor reflex takes place to increase the heart rate. The direct effect on the heart is that this decreases the heart rate, so in many cases, it neutralizes. You would think major outcome is decreased blood pressure which counteracts slowing of heart rate but this is only true if heart is healthy (which wouldn't happen in a patient on verapamil) so in patients on verapamil, there is usually slowing on heart rate. |
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Term
| First pass effect with Verapamil |
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Definition
| Large amount changed as it is absorbed acrossGI mucosa, by the time it gets to the blood stream, dose of drug is significantly lower than the amount the patient swallowed |
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Term
| Where is verapamil metabolized |
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Definition
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Term
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Definition
(all related to blocking of calcium channel blockers)
-Constipation (most common)
- Vasodilation causes dizziness, headache, edema of feet
- Gingival hyperplasia
-Cardiac Effects (heart block and bradycardia can be seen with too much effects of what the drug is given for) |
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Term
| Where are major sites of actions of Diltiazem? |
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Definition
predominant action on myocardium (decrease heart rate, decrease conduction, decrease force of conduction
also has some effect on VSM vasodilation |
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Term
| First pass effect of diltiazem |
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Definition
| has some first pass effect, less so than verapamil |
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Term
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Definition
-Constipation (less than verapamil)
- less likely to cause bradycardia |
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Term
| 4 major Uses for diltiazem and verapamil |
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Definition
Angina
Hypertension
Dysrhythmias
Migrane prophylaxis |
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Term
| Differences between side effects of diltiazem and verapamil |
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Definition
| Verapamil more likely to cause constipation and more likely to cause cardiac effects (bradycardia, heart block) |
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Term
| Major effects of Nifedipine? |
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Definition
| action on VSM causing vasodilation, which activates baroreceptors. Almost no direct effect on the myocardium (no decreasing in heart rate, force of contraction) |
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Term
| 2 common clinical application of Nifedipine? |
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Definition
| to treat high blood pressure mostly and also angina |
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Term
| Indirect effect of Nifedipine? |
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Definition
| Baroreceptor reflex. This is more likely. Tachycardia comes from lowering blood pressure |
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Term
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Definition
| -Vasodilation (most common) dizziness, HA, edema (ALMOST ALWAYS HAVE EDMA THROUGHOUT ENTIRE TIME ON DRUG) |
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Term
| What happens to patient with underlying angina that then takes Nifedipine? |
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Definition
| reflex tacycardia increases oxygen demand of the heart cells, and can make angina worse. So not usually used in people with angina because worsens problems in some people |
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Term
| What do all dihydropyridines end in? |
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Definition
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Term
| What dihydropyridine is NOT used for HT or angina and what is it used for? |
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Definition
| Nimodipine - not used for cardiac. It has specific effects on arterioles inside the cranium. It's application is to prevent arterial spasm in a patient that has a sub-aracnoid bleed. |
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Term
| What is the only dihydropyridine that is given intravenously? |
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Definition
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Term
| Drug most likely to cause Heart Block? |
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Definition
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Term
| Drug most likely to cause Constipation? |
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Definition
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Term
| Most Likely to cause ankle edema? |
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Definition
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