E3: Antianginals-Nitrates Flashcards
Nitroglycerin Storage
amber glass containers- air-tight, water-tight, light resistant
Dosage forms
GoNitro:
NitroStat:
NitroMist:
Nitrol, Nitro-BID:
GoNitro: sublingual powder
NitroStat: sublingual tablet
NitroMist: transligual spray
Nitrol, Nitro-BID: ointment
Why do you have to take the Transdermal nitroglycerin patches off at night
Tolerance to effect observed with constant use
Isosorbide Dinitrate (ISDN)
Use
Duration of effect for IR and ER
prophylactic management of
chronic stabile angina
IR: 4-6 hr
ER: 8hr
Isosorbide mononitrate (ISMO)
Use
Duration of effect for IR and ER
SAR
- prophylactic management of chronic stabile angina
IR: 6 hr
ER: 12hr
SAR: - active metabolite of ISDN
- onset of action not quick enough to use for acute attacks
Sodium Nitroprusside-Nitropress® IV
General Information
MOA
Pharmacology
ADR* BBW
General Information
1. indicated for hypertensive emergencies
MOA: Nitric Oxide Donor
Pharmacology
1. releases NO spontaneously
2. nonselective (arteries and veins) vasodilator
ADR
thiocyanate accumulation: hypothyroidism
Amyl Nitrate-Rush Poppers
Use
DOA
inhalant used for euphoria, excitement, disinhibition
Commonly abused
short DOA : 3-5 min
When to take NTG SL
Acute attack
1 at onset, if no relief call 911
can take SL prior to activity to prevent angina; last ~ 40 min
Nitrates MOA (overall)
Nitrate Pharmacology (3)
ADR
MOA
1. organic nitrates release ONO2
2. enzymatic activation
3. ↑ nitric oxide (NO) that binds to sGC leading to an ↑ cGMP
4. causes relaxation of vascular smooth muscle (vasodilation)
Pharmacology:
A. systemic venodilation (↓ preload)
1) decreasing work demands on the heart by ↓ filling pressures
B. systemic arteriolar dilation (↓ afterload)
1) leads to a reduction in arterial resistance
C. coronary artery dilation
1) may redistribute myocardial blood flow from non-ischemic areas to ischemic areas, thus ↑ O2 supply and satisfying local
O2 demands
2) not the primary action
Nitrate tolerance
Define
How to reverse (what specific terminology)
- gradual diminishing effectiveness with each dose; tends to be partial and
not absolute
A. sulfhydryl depletion
1) cysteine aa w/sulfhydryl moiety gets depleted so can’t convert ONO2 to NO - reversal of tolerance accomplished by
A. intermittent dosing; take the patch off at night
B. SR preps dosed BID at 8 am and 3 pm (cover 12 hrs total)
NOTE: washout periods when [nitrate]pl ↓ at night often require combination therapy for anginal coverage
Nitrate + PDE5 inhibitors
acute hypotension
1) nitrates dilate systemic vascular as well as coronary arteries
a) Viagra® causes only mild dilation (if any) of systemic and
coronary blood vessels by itself
2) when combined together or with toxic blood levels (P450 inhibition,
alcoholism), a significant ↓ of BP can occur resulting in ↓ coronary artery and systemic blood vessel perfusion
3) this ↓ BP in itself can result in increased ischemia in the heart or the
reflex tachycardia associated with the ↓ systemic BP can cause cardiac ischemia resulting in angina –> MI
- when on Sildenafil wait 24 hrs to administer NTG; tadalafil 48 hrs
-Nitrates ↑ cGMP production
-PDE5 inhibitors ↓cGMP degradation
-EXCESS vasodilation –> Hypotension
What drug is the first race specific FDA approval?
What is its indication
Pharmacodynamics?
Isosorbide dinitrate/hydralazine-Bidil®
HF
Pharmacodynamics:
1. ↑ NO production
2. arterial vasodilation
3. venodilation
4. hydralazine may prevent tolerance
ranolazine-Ranexa® ER 500mg
Indication (2)
MOA
Pharmacology:
Indication:
1. Chronic stable angina
↑ exercise duration
↓ frequency of anginal attacks
↓ need for nitroglycerin use
B. adjunctive therapy to be added to BARB, CCB or nitrates
C. not used alone
2. Class I antiarrhythmic action (Na+ channel blocker)
MOA: Na+ channel blocker
Pharmacology: blocks late Na current through cardiac Na channels
A. ↓ Ca++ overload intracellularly
