Drugs for Angina Pectoris and Acute Coronary Syndrome

Question 1

What is angina pectoris?

Answer 1

chest pain caused by reduced O2 supply to mycardium => anaerobic metabilism => acute lactic acidosis => irritates nerve endings => pain
(basically, not enough O2 to supply demand)

Risk factors: obesity, smoking

Question 2

Drugs for angina

Answer 2

↓ O2 demand by myocardium
↓ preload, contractility, afterload, HR
⇡ blood supply (O2 supply) to myocardium

Examples:
BBs
CCBs
Nitrates (NTG, isosorbides)

Question 3

Nitrates: MOA

Answer 3

vasodilation of veins (primarily)
- ↓ venous return to heart => ↓ preload => ↓ cardiac workload (↓ O2 demand)

vasodilation of arteries
- ↓ SVR, after load => ↓ cardiac workload (O2 demand)

vasodilation of coronary arteries
- ⇡ blood flow to myocardium (⇡ O2 supply)

Question 4

nitrates: NTG = nitroglycerin

Answer 4

• high first-pass rate, so no PO
  SL or spray
• immediate onset, short duration
• may repeat q 5 min x3

Paste or patch

• slow onset, longer duration (q 12 hrs)
• pt may develop tolerance => have a “patch free” schedule

IV - in an emergency

monitor BP - may cause low BP

Question 5

nitrates: Isorsorbide

Answer 5

• slow onset and long duration
• action = identical to nitroglycerin
• indication - treatment and prevention of angina
• pt may develop tolerance
• rapid w/drawal may cause vasospasm

isorsorbide dinitrate (Isordil)
isorsorbide mononitrate (Imdur)

Question 6

Nitrate: side effects

Answer 6

• severe headache initially, then ↓ (due to vasodilating effect)
• dizzy, lightheadedness, fainting, flushing
• orthostatic hypotension
• reflex tachycardia
• Check BP

Question 7

drug-drug interactions: nitrates

Answer 7

nitrates + hypotensive drugs
- may intensify vasodilation

nitrates + phosphodiesterase type 5 inhibitors (PDE 5 inhibitors)
- severe hypotension = fatal
- examples: 
sildenafil (Viagra)
tadalafil (Cialis)
vardenafil (Levitra)

Question 8

NI and pt edu: nitrates

Answer 8

Never ignore chest pain - may feel like pressure or dull pain

Avoid alcohol and PDE-5 inhibitors

Assess pain (PQRST)

Question 9

treatment for chronic stable angina

Answer 9

drug therapy

• anti-platelet aggregation drugs
• cholesterol-lowering agents
• ACEIs
• anti-anginal agents (nitrates, BBs, CCBs)

Question 10

Acute Coronary Syndrome (ACS)

Answer 10

• leading cause of death in US
• > 2 million pt are admitted to hospital
  1/3 STEMI
  2/3 NSTEMI

Occurs when a lipid-rich atheromatous plaque ruptures and forms a thrombus -> may occlude coronary artery -> ischemic discomfort

Question 11

symptoms of Acute Coronary Syndrome (ACS)

Answer 11

• classic angina-type pain (67% men vs 38% women)
• atypical presentation in women and elderly
  = no pain
  = syncope, palpitations, generalized weakness
  = DKA

Question 12

Treatment for ACS - myocardial infarction (MI)

Answer 12

O BATMAN
Oxygen
Beta blockers - IV
ASA (aspirin) PO or PR (by rectum = suppository)
Thrombolytics (or anti-coagulants) - IV
Morphine (IV) = narcotics
ACEI (PO)
Nitroglycerin (SL, paste or IV)