Pharmacology 1: Blood, Heart, HTN Flashcards
Aspirin MOA
Decreases platelet aggregation; Irreversible platelet effect
Aspirin ADRs
Dyspepsia->GI bleeding
Kids w/ viral infection = Reyes Syndrome
Associated w/ SNHL (ringing) = salicylism
Bronchospasm in asthma patients
ASA triad = asthma, nasal polyps, ASA intolerance
Clopidogrel MOA
irreversible platelet binding
Warfarin MOA
antagonizes vit V epoxide reductase complex 1 (VKORC1)
What proteins does warfarin inhibit?
II, VII, IX, X
and
Protein C& S
How to reverse warfarin?
- Non life threatening hemorrhage = vitamin K PO
- life threatening hemorrhage = IV vit K + prothrombin complex concentrates (PCC > FFP)
Warfarin Interactions
Substrate CYP2C9
ABX often cause issues w/ warfarin (don’t let warfarin leave the body)
Warfarin ADRs
- bleeding, hemorrhage
- purple (blue) toe syndrome
- warfarin induced skin necrosis (rare)
- TERATOGENIC
UFH MOA
indirect thrombin inhibitor inactivates IIa (thrombin)> Xa LL XIIa, Xia & IXa
how to monitor UFH
monitor platelets
check aPTT
How to reverse UFH
Turn down/stop heparin
if urgent = protamine (only when desperate b/c if ever need this again there is a 1% risk of anaphylaxis)
FFP/PCC does not reverse heparin products
ADRs of UFH
Bleeding/hemorrhage
HIT (transient decrease in platelets; insignificant)
HITTS aka HIT type 2 (more serious)
LMWH drug names & MOA
Enoxaparin (other -parin drugs)
Inactivated factor Xa»_space; IIa
How to monitor LMWH
Don’t measure PT/PTT can measure anti-Xa levels to check anticoagulation
*monitoring is most helpful during treatment not prophylaxis
ADRs of LMWH
Injection site pain/hematoma
Hemorrhage < than w/ heparin
thrombocytopenia < than w/ heparin
**category B in pregnancy
-aban drug MOA & indications
Rivaroxaban, Apixaban
direct Xa inhibitors
approved for nonvalvular a fib and VTE prophylaxis and treatment
Dabigatran MOA & indications
direct thrombi inhibitor
approved for non-valvular atrial fib
Statin MOA
inhibition of HMG CoA reductase causes up regulation of LDL receptor gene and causes decrease of LDL
Clinical monitoring in patients on statins
LFTs: at baseline and recheck if indicated
CPK (if myalgia symptoms)
FLP (3-4 wks after initiation, then yearly once at goal)
Statin interactions
Simvastatin and atorvastain are CYP3A4 & P glycoprotine substrates
**additive myopathy/hepatotoxicity w/ niacin/fibrates
Statin ADRs
- mylagia/myopathy
- reversible hepatotoxicity
- increased blood glucose
- category X in pregnancy
Fibrates names and indication
Gemfibrozil and fenofibrate
-use for hyertriglyceridemia when pancreatitis is a risk
Fibrate interactions
careful w/ stains b/c of overlapping toxicity profiles
Fibrates ADRS
reversible hepatotoxicity and myopathy
Niacin indication
modifies all lipoproteins and lipids favorably
Niacin interactions
careful w/ cadmic of statins & fibrates b/c of overlapping toxicities
Niacin ADR
- prostaglandin related = flushing (Niaspan extended release causes least flushing and hepatotoxicity)
- aggravate glucose intolerance
- aggravate gout
Antiarrhythmic drug class ADR
- All anti-arrhythmic drugs can CAUSE arrhythmias which may be fatal
- QT prolongation
- careful in pts w/ bradycardia/heart blocks
Torsades is more common with
hypokalemia, hypomagnesemia, and bradycardia
Antiarrhythmic class interactions
- avoid other QT prolongers (IE: macrolides)
- most are metab by CYP3A4 or 2D6
- drugs that cause hypokalemia/hypomag (IE loop diuretics) increase toxicity risk
Class I antiarrhythmics : list and MOA
Modulate or block Na channels
- Ia = Quinidine, procainamide, disopyramide
- Ib = lidocaine, mexiletine
- Ic = flecainide, propafenone
Class II antiarrhythmics: list and MOA
inhibit sympathetic activity
-beta blockers
Class III antiarrhythmics: list and MOA
block K channels
-sotolol, defotilide, ibutilide, AMIODARONE, dronedarone
Class IV antiarrhytmics: list and MOA
block Ca2+ channels
-verapamil and diltiazem
Amiodarone Interactions
- likely inhibits p-glycoprotein so digoxin excretion may be effected
- avoid other QT prolongers
- multiple CYP concerns
Amiodarone ADR
1) cardiac toxicity = Bradycardia and AV nodal block
2) Pulmonary toxicity (subacute cough and progressive dyspnea associated w/ patchy interstitial infiltrates on CXR: tx = d/c amiodarone + supportive measures +/- steroids)
3) Thyroid Toxicity (hypothyroidism from excess iodine)
4) Dermatologic Toxicity (photosensitivity, recommend sunscreen if repeated sun exposure = bluish skin discoloration)
NONdihydropyridine CCB list and usages
Diltiazem is used more than verapamil
-dysrthmias (SVT, afib) > HTN (rate drug not HTN drug)
NONdihyrdopyridine CCB ADRs
- hypotension, bradycardia, - ionotrope, peripheral edema
- headache
- *w/ verapamil constipation is common
Digoxin indications
- rate control in afib
- Heart failure is most likely
- *doesnt alter mortality
Digoxin Interactions
Oral steroids and diuretics decrease K or Mg and increase digoxin distribution to the heart and muscles = increased toxicity
Digoxin ADR-Acute toxicity
Rhythm disturbance is most concerning = PVC
Digoxin ADR-Chronic toxicity
Rhythm disturbance - PVC
Yellow/green or blurred vision
Loop diuretic MOA
-interferes w/ Na/K exchange in ASCENDING segment of loop of henle by inhibiting Na/K ATPase
Thiazide diuretic MOA
-interferes w/ K/Na exchange in early DISTAL CONVOLUTED tubule by inhibiting Na/K ATPase
Loop diuretic indications
- edematous states (HF)
- acute hypercalcemia
Thiazide diuretic indications
-essential HTN
Loop and thiazide diuretic interactions
hypotension w/ other antiHTN
digoxin and lithium toxicity via electrolyte alterations
Diuretic ADRs
- Electrolyte disturbances (loops > thiazides)
- HYPOKALEMIA > hyponatremia
- orthostatic hypotension
- glucose intolerance
- hyperuricemia
ACEI MOA
vasodialtes efferent arteriole (decreasing glomerular pressure)
ACEI ADRs
Cough
HYPERKALEMIA
Angioedema (more common in blacks, #1 drug to cause)
Birth defects contraindication = pregnancy
alpha adrengergic blocker ADR
**postural hypotension common = titrate drug
sedation/fatigue
nasal congestion
Non Selective B blockers
Propranolol (more bronchospasm)
B1 selective B blockers
Metoprolol > atenolol
B blockers w/ alpha blocking activity
Carvedilol
more for heart failure than HTN
Betablocker ADRs
bradycardia, bronchospasm, erectile dysfunction, exercise intolerance
CCB - Dihydropyridines
1st gen = nifedipine (fast acting)
2nd gen = amlodipine
Clinical use of dihydropyridine CCB
HTN, Angina, Reyndaud phenomenon
ADRs of dihydropyridine CCB
HEADACHE, dizziness/lightheadedness
-peripheral edema, reflex tachycardia
GINGIVAL HYPERPLASIA (nifedipine > amlodipine)
Other meds that cause gingival hyperplasia
Phenytoin and Cyclosporine A (immunosuppressant)
