Exam 2 - Anti-anginal & other vasodilators Flashcards
Nitroglycerin and Isosorbide dinitrate belong to what class of drugs?
Nitrates/Nitrites
What is the MOA for Nitrates/Nitrates?
Stimulates NO production which will produce cGMP and ultimately lead to vasodilation
What is the DOC for ACUTE anginal attacks?
Nitrates/Nitrites (Nitroglycerin, Isosorbide dinitrate)
What is the predominant mechanism of Nitrates/Nitrites that allow them to provide anginal relief?
They decrease myocardial O2 requirement
Why is the sublingual administration of Nitrates/Nitrites preferred?
- Avoid hepatic destruction
- Rapid absorption
- Immediate anginal relief within 1-3 minutes
What are some adverse effects of Nitrates/Nitrites?
Pronounced vasodilation can lead to:
- Throbbing HA
- Orthostatic hypotension
- Reflex tachycardia
Frequent exposure can lead to tolerance or marked reduction of most effects (not suitable for long-term treatment)
What are CCBs good for in regards to angina?
Good for CHRONIC angina treatment and not for immediate relief
Why is slow release nifedipine (a CCB) only indicated in HTN and not angina?
May provoke angina pectoris due to possible reflex tachycardia
B-blockers have CV effects at what 3 organs?
- Heart: Decrease CO
- Kidneys: Decrease renin
- CNS: Decrease SNS tone
How to B-blockers provide anginal relief?
Decrease oxygen demand
Why are B-blockers not used for variant angina?
B-blockers are ineffective in producing coronary vasodilation/will not dilate spastic vessels
What are adverse effects of B-blockers?
- Bronchoconstriction (do not use in asthmatics)
- Increase plasma triglycerides
- Decrease insulin and hypoglycemic response (do not use in diabetics)
- CNS side-effects
What is the MOA for Ranolazine?
- Partial fatty-acid oxidation inhibitor and decreases O2 consumption in ischemic tissue
- Inhibits late inward sodium current, decreasing contractility
What are uses for Ranolazine?
- Angina
- Reduces left ventricular wall stiffness and increases coronary circulation
***Last choice drug and only used when other meds have not worked
What is the preferred treatment for variant or angiospastic angina?
Nitrates or CCBs
What is the most effective drug combination for treatment of angina pectoris?
B-blockers and a vasodilator (nitrate/CCB)
What class of drug is Sildenafil (Viagra)?
PDE-5 Inhibitor
What is the MOA for Sildenafil (Viagra)?
Inhibits PDE-5 from degrading cGMP into GMP, allowing accumulation of cGMP and vasodilation
What is Sildenafil (Viagra) used for?
- ED
- Pulmonary HTN
When is the max concentration of Sildenafil (Viagra) reached?
Within 30-120 minutes
What is Sildenafil (Viagra) metabolized by?
Primarily by CYP3A4
What are some adverse effects of Sildenafil (Viagra)?
- Headache, flushing, nasal congestion (due to vasodilation)
- Visual impairment (can also partially inhibit PDE6 in the retina)
What are contraindications to using Sildenafil (Viagra)?
- Inhibitors of CYP3A4 and 2C9 (will reduce its clearance, leading to build up and increased adverse effects)
- Concurrent treatment with nitrates/nitrates (will have too much vasodilation)
- Concurrent use with alpha blockers (symptomatic hypotension)
- Use in pregnant or lactating women, infants, children
It is contraindicated to use Sildenafil (Viagra) with inhibitors of CYP3A4 and 2C9 isoenzymes. What are some examples of these enzymes?
- Ritonavir
- “azoles”
- Cimetidine (OTC antiacid and grapefruit juice)
- Erythromycin
- Quinidine
