Information about the importance of the platelet and functions.
Classification of drugs used for antiplatelet properties. And a brief discussion about the drugs.
9. ANTIPLATELET AGENTS
DRUG NAME aspirin clopidogrel, prasugrel, ticagrelor, cangrelor
CLASS NSAID ADP receptor inhibitors
MECHANISM OF
ACTION
•Irreversibly inhibits cyclooxygenase enzymes
(COX-1, COX-2)
•Reduces thromboxane A2 synthesis by platelets
•Reduces platelet activation and aggregation
•Inhibit the ADP receptor P2Y12 on platelets
(all irreversibly, except for ticagrelor)
•Prevent ADP binding to platelets and
glycoprotein IIb/IIIa activation
INDICATIONS
•Myocardial infarction
•Ischemic stroke
•Transient ischemic attack
•Cardiac valve replacement
•Coronary angioplasty
•Peripheral artery disease
ROA PO PO - Cangrelor: IV
SIDE EFFECTS
Common side effects; Undue bleeding: bruising, bleeding gums, hematuria, epistaxis, and
gastrointestinal bleeding, Headache, fatigue, nausea, and vomiting
•Boxed warning: gastritis, gastric ulcers, and bleeding
•Hypersensitivity reactions: anaphylaxis,
bronchoconstriction, dyspnea, and wheezing
•Chronic use: renal insufficiency; ototoxicity
•Ticagrelor: dyspnea, cough, and back
pain
•Boxed warning (prasugrel and
ticagrelor): serious and fatal bleeding
10. ANTIPLATELET AGENTS
DRUG NAME cilostazol, dipyridamole abciximab, eptifibatide, tirofiban
CLASS Phosphodiesterase inhibitors Glycoprotein IIb/IIIa inhibitors
MECHANISM OF
ACTION
•Reversibly inhibit platelet phosphodiesterase III, which increases cAMP
levels. Inhibit uptake of adenosine molecules, which signal the increase
of cAMP within platelets. Reduce ADP-induced platelet aggregation
•Inhibit vascular smooth muscle phosphodiesterase III, which increases
cGMP, causing vasodilation
•Reversibly inhibit the glycoprotein IIb/IIIa
receptors on platelets
•Prevent platelets from binding to fibrinogen
and forming a platelet plug
INDICATIONS
•Myocardial infarction
•Ischemic stroke
•Transient ischemic attack
•Cardiac valve replacement
•Coronary angioplasty
•Peripheral artery disease
ROA PO IV
SIDE EFFECTS
•Common side effects - Undue bleeding: bruising, bleeding gums, hematuria, epistaxis, and gastrointestinal bleeding
•Headache, fatigue, nausea, and vomiting
•Skin rash, Stevens-Johnson syndrome
•Tachycardia and palpitations, Orthostatic hypotension
•Boxed warning (cilostazol): heart failure
•Thrombocytopenia, serious bleeding
•Anaphylaxis
CONTRA
INDICATIONS
AND CAUTIONS
Active internal bleeding, suspected aortic dissection, recent trauma in the past three months, history of intracranial
hemorrhage or ischemic stroke in the past three months, coagulopathies or bleeding disorders, before major surgeries,
pregnancy and breastfeeding Cilostazol: heart failure
Use with caution - Active peptic ulcer, renal or hepatic impairment
Drug interaction - Anticoagulants like heparin and warfarin; thrombolytic medications like alteplase, reteplase, and
Tenecteplase
11. ANTIPLATELET AGENTS
ASSESSMENT
AND
MONITORING
Assess Vital signs, Laboratory test results; e.g., CBC, PT, aPTT, lipid profile, liver and renal function tests
Client history; e.g., cilostazol: heart failure
Monitor Laboratory test results; side effects
•Desired therapeutic effects; e.g., absence of thrombotic events, decreased claudication
CLIENT
EDUCATION
•Lifestyle modifications E.g., low sodium, low refined sugar, low fat, high fiber diet; physical activity as
tolerated; weight reduction as indicated; smoking cessation, alcohol in moderation
Clopidogrel Purpose of medication: inhibit platelet activity, formation of clots; decrease risk of thrombotic
events
•Take once each day with or without food at the same time each day
•Common side effects: bleeding
• Report unusual bruising, signs of bleeding
• Seek medical attention for signs / symptoms of significant bleeding; e.g., dark urine or stools,
coughing up blood, or sudden headache or back pain
•Seek immediate emergency care for sudden onset of confusion, vision changes, trouble speaking, one-sided
weakness
•Review bleeding precautions; Report use of antiplatelet medication to all healthcare providers; consult with
primary healthcare provider before invasive procedures
Cilostazol Purpose of medication: reduce the symptoms of intermittent claudication
•Takes a few weeks to notice improvement; continue medication as prescribed
•Take medication on an empty stomach either 30 minutes before or 2 hours after a meal
•Side effects; e.g., tachycardia, palpitations, headache, dizziness, diarrhea
•Report signs / symptoms of Stevens-Johnson syndrome; e.g., rash, blistering, fever
•Interacts with many other prescription / non-prescription medications, vitamins, and herbal products.Talk
with healthcare provider before taking medication or supplement
