19 - Pharmacology Anti-Anginal Flashcards
Isosorbide Mononitrate
IMDUR
DOSING
Mononitrate = active metabolite of DINITRATE
excellent BV after ORAL admin & longer t1/2 than dinitrate
SUSTAINED RELEASE
IMDUR
ONCE DAILY
VV
formulation already provides nitrate-free interval
Calcium Channel Blockers
DHP = Nifedipine / amlodipine / nicardipine
Verapamil / Diltiazem
MoA for ANGINA
Calcium –> myocyte triggers calcium release
calcium binds TROPONIN
Troponin - Calcium complex allows:
Actin & Myosin to interact & Contract
CCBs BLOCK initial Calcium Influx** –> **↓CONTRACTILITY
2nd effect:
Calcium –> VASCULAR SMOOTH MUSCLE
Calcium - Calmodulin complex permits the same
net effect = VASODILATION
3 Types of Angina:
Unstable Angina
Unstable Angina = Acute Coronary Syndrome
Usually occurs while:
RESTING
Atherosclerotic plaque RUPTURES
plug forms = clotting
VV
Blocks FLOW to heart muscle
EMERGENCY
treatment
3 Types of Angina:
Stable Angina
Classic / Effort / Predictable
Stable plaque –> ↓Maximal Capacity of Coronary Artery
- *Can be relieved by**:
- *Rest** or Nitroglycerin
3 Types of Angina:
Prinzmetal’s Angina
Prinzmetal’s Angina = Vasospastic Angina
Unstable form of Angina
Transient ↓blood flow
caused by
Coronary Artery SPASM
can occur:
with or WITHOUT ACSCD
Ranolazine** = **Ranexa
Angina MoA
Used in those with chronic stable angina who
have NOT had adequate response with other antianginal drugs
INHIBITS:
late entry of SODIUM –> cardiac myocytes
↓Intracellular Na –> ↑Calcium Expulsion via Na/Ca Transporter
↓accumulation of Na/Ca in myocardial cells
VV
Helps myocardium use energy MORE EFFICIENTLY
UNIQUE:
- does NOT effect:*
- *HR / BP / Vascular Resistance**
DHP CCB’s
Angina Action & ADR
↑Selectivity for Vascular Smooth Muscle >> myocardium
↑Vasodilation >> verapamil/diltiazem
Vasodilation -> ↓BP -> ↓cardiac work -> antiANGINAL effect
↓Coronary Resistance** –> ↑**Coronary Blood Flow
Strong reflex beta-adrenergic effect:
offsets negative inotropic drug effect like reflex tachycardia
ADR:
Peripheral Vasodilation** –> **Peripheral Edema** & **Flushing Headaches
more common in SHORT ACTING nifedipine
Beta Blocker’s
ADRs
↓HR ↓Contractility ↓AV Node conduction
Bronchoconstriction
due to b2 blockade = non-selective agents & high doses of selective ones
Peripheral Artery disease** or **Raynaud’s Disease
from non-selective drugs
CNS effects
Nigtmares / insomnia / hallucinations
Fatigue
↓cardiac output or CNS effect
Erectile Dysfunction
due to low BP
Ranolazine = Ranexa
ADR / Contraindications
Prolongation of QT** / **↑BP
Can be used in COMBO with:
Beta Blockers / Nitrates / AMLODIPINE
Contraindications:
Patients with preexisting QT prolongation or drugs that do so
DILTIAZEM** & **VERAPAMIL
potent / moderate INHIBITORS of CYP3A4
hepatic disease
Nitrate
Effect
- ↓*Myocardial O2 Demand=main effect
- workload of heart reduces*
Dilates systemic VEINS
↓Preload = left ventricular end diastolic pressure
↓ventricular wall stress
↓CO
Secondary Effect = not thought to be main therapeutic effect
Coronary Vasodilator
↓arterial spasm of variant angina
↑Coronary perfusion / ↑ Oxygen delivery
Isosorbide Mononitrate
ISMO / MONOKET
DOSING
Mononitrate = active metabolite of DINITRATE
excellent BV after ORAL admin & longer t1/2 than dinitrate
IMMEDIATE RELEASE TABLET
Ismo / Monoket
2 Times Daily - 7 Hours apart
VV
provides nitrate-free interval
Therapeutic Uses of:
SL Nitroglycerin
&
Translingual Nitroglycerin Spray
- *TERMINATE**
- *Acute Anginal Attacks**
- *PROPHYLAXIS**
- *Acute Anginas**
Sublingual Nitroglycerin
COUNSELING
Place under tongue & leave there to dissolve
CONTACT EMERGENCY MEDICAL SERVICES
if there is
no pain relief or pain WORSENS after 5 minutes
Continue to take
- *ADDITIONAL SL NITROGLYCERIN** while waiting for ambulence
- *_<_3 doses** @ 5 minute intervals
Nitrates
MoA
Nitroglycerin –> Vascular Smooth Muscle
converted into
Nitric Oxide** –> activates **Guanylyl Cyclase
↑cGMP –> dephosphorylates MYOSIN-LC-P
VV
instead of contraction –> RELAXATION of myosin
Higher Doses of Nitrates
Effect
Higher doses –> further venous pooling
↓Arteriolar Resistance
↓Peripheral Resistance –> ↓BLOOD PRESSURE
VVV
REFLEX TACHYCARDIA POSSIBLE
Angina
What is seen on an ECG?
DEPRESSED** - **ST-Segment
