Dosing and uses of Aggrenox (aspirin-dipyridamole)
Adult dosage forms and strengths
aspirin/dipyridamole
capsule, extended release
- 25mg/200mg
Stroke
Secondary prophylaxis of transient ischemic attack (TIA) or cerebrovascular accident (CVA)
1 capsule PO q12hr
Dosing considerations
- Not interchangeable with individual components of aspirin/dipyridamole
- Intolerable headaches during initial treatment: Switch to 1 capsule PO at bedtime; patient should return to normal regimen when possible (usually 1 week)
Dosing Modifications
GFR <10 mL/min: Use not recommended
Administration
Swallow capsules whole, without chewing
Pediatric dosage forms and strengths
Safety and efficacy not established
Aggrenox (aspirin-dipyridamole) adverse (side) effects
>10%
Headache (10-39%)
Dyspepsia (4-18%)
Abdominal pain (4-18%)
Nausea (6-16%)
Diarrhea (13%)
1-10%
Vomiting (3-8%)
Pain (6%)
Fatigue (6%)
Arthralgia (5%)
Back pain (5%)
Hemorrhage, nonspecific (3%)
Accidental injury (3%)
Epistaxis (3%)
Amnesia (3%)
Arthritis (2%)
Melena (2%)
Asthenia (2%)
Convulsions (2%)
Neoplasm, nonspecific (2%)
Anemia (2%)
Rectal hemorrhage (2%)
Malaise (2%)
Cardiac failure (2%)
Coughing (2%)
Purpura (1%)
GI hemorrhage (1%)
Anorexia (1%)
Somnolence (1%)
Myalgia (1%)
Arthrosis (1%)
Confusion (1%)
Hemorrhoids (1%)
Syncope (1%)
Upper respiratory tract infection (1%)
Postmarketing Reports
Body as whole: Hypothermia, chest pain
Cardiovascular: Angina pectoris
CNS: Cerebral edema
Fluid and electrolyte: Hyperkalemia, metabolic acidosis, respiratory alkalosis, hypokalemia
GI: Pancreatitis, Reye syndrome, hematemesis
General: Hearing loss, anorexia, aplastic anemia, migraine, pancytopenia, thrombocytosis, allergic vasculitis, prothrombin time (PT) prolongation, disseminated intravascular coagulation (DIC), coagulopathy, thrombocytopenia
Immune: Hypersensitivity, acute anaphylaxis, laryngeal edema
Hepatic: Hepatitis, hepatic failure
Musculoskeletal: Rhabdomyolysis
Metabolic: Hypoglycemia, dehydration
Reproductive: Prolonged pregnancy and labor, stillbirths, lower-birth-weight infants, antepartum and postpartum bleeding
Respiratory: Tachypnea, dyspnea
Skin: Rash, alopecia, angioedema, Stevens-Johnson syndrome, skin hemorrhage (eg, bruising, ecchymosis, hematoma)
Urogenital: Interstitial nephritis, papillary necrosis, proteinuria
Warnings
Contraindications
Hypersensitivity to aspirin, dipyridamole, or NSAIDs
Syndrome of asthma, rhinitis, and nasal polyps
Children younger than 16 years with viral infections (risk of Reye syndrome)
Cautions
Discontinue if tinnitus or impaired hearing occurs
Use with caution in patients with cardiovascular or GI diseases or bleeding disorders
Risk of precipitation of chest pain in patients with underlying coronary artery disease (CAD)
Dosage in drug may not be adequate in patients with history of stroke or TIA for whom aspirin is indicated to prevent recurrent MI or angina pectoris
Preexisting hypotension may be exacerbated by peripheral vasodilation
Increased bleeding risk when drug coadministered with antiplatelet agents (eg, anagrelide), anticoagulants (eg, heparin), fibrinolytic agents, or NSAIDs (in long-term use)
When possible, surgical patients should not receive aspirin 2 weeks before undergoing a surgical procedure
Increased bleeding risk with chronic heavy alcohol use (>3 alcoholic drinks/day)
Risk of elevated liver function test values or hepatic failure with dipyridamole administration
Pregnancy and lactation
Pregnancy category: d
Lactation: Drug enters breast milk; use with caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Aggrenox (aspirin-dipyridamole)
Mechanism of action
Aspirin: Inhibits platelet cyclooxygenase and thus inhibits generation of thromboxane A2, a powerful inducer of platelet aggregation and vasoconstriction, leading to abrogation of platelet aggregation
Dipyridamole: Inhibits uptake of adenosine into platelets, endothelial cells, and erythrocytes
Combination of aspirin and dipyridamole produces additive antiplatelet effects
Absorption
Peak plasma levels: Dipyridamole, 2 hr
Distribution
Protein bound: Dipyridamole, 99%
Vd: Dipyridamole, 92 L
Metabolism
Metabolized by liver: Dipyridamole
Elimination
Dipyridamole: Feces (95%), urine (5%)
