Aspirin + Dipyridamole

Indications

Aspirin + Dipyridamole is used for: Secondary prophylaxis of transient ischemic attack (TIA), cerebrovascular accident (CVA)

Adult Dose

Stroke Secondary prophylaxis of transient ischemic attack (TIA) or cerebrovascular accident (CVA) Adult: 1 capsule bid Hepatic impairment: Avoid in severe impairment.

Child Dose

Renal Dose

Renal impairment: CrCl (ml/min) <10: Avoid.

Administration

May be taken with or without food. Swallow whole, do not chew/crush.

Contra Indications

Hypersensitivity, allergy to NSAIDs. Bleeding disorders (factor VII or IX deficiencies). Patients with asthma, rhinitis or nasal polyps. Children <16 yr with viral infections.

Precautions

Unstable angina, recent MI, subaortic stenosis, severe coronary artery disease, hypotension, history of peptic ulcer disease. Monitor for signs of ulceration or bleeding, even in the absence of previous GI symptoms. Patients with inherited or acquired bleeding disorders. Admin of dipyridamole may cause increase in hepatic enzymes and hepatic failure. Avoid aspirin in patients with severe renal failure (CrCl <10 mL/minute). Discontinue if tinnitus or impaired hearing occurs. Dose of aspirin in this preparation is insufficient to prevent MI. Pregnancy, lactation. Lactation: Drug enters breast milk; use with caution

Pregnancy-Lactation

Pregnancy Available data from published studies and postmarketing experience with use during pregnancy have not identified clear association between drug use and major birth defects, miscarriage, or adverse maternal or fetal outcomes drug combination contains low-dose aspirin which is an NSAID Increases risk for bleeding; maternal use of high-dose aspirin can result in excessive blood loss at delivery, prolonged gestation, prolonged labor, intracranial hemorrhage in premature infants, low birth weight, stillbirth, and neonatal death Lactation Based on data from a clinical lactation study in breastfeeding women taking low-dose aspirin, the metabolite salicylic acid is present in human milk in low levels; dipyridamole is also present in human milk; there is no information on the effects of drug combination components on breastfed infant or on milk production; there is insufficient information to determine effects of aspirin on breastfed infant and no information on effects of aspirin on milk production; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed child from therapy or from underlying maternal condition

Interactions

Aspirin: May reduce hypotensive and hyponatraemic effects of ACE inhibitors; may increase serum levels and toxicity of acetazolamide; increases anticoagulant effect of heparin, thus increasing bleeding risk; may reduce hypotensive effect of β-blockers; may reduce efficacy of diuretics in patients with underlying renal or CV disease; salicylate may inhibit renal clearance of methotrexate, thus increasing the risk of bone marrow toxicity; increased risk of bleeding or reduced renal function when used with NSAIDs; increased risk of hypoglycaemia when used with oral hypoglycaemic drugs; salicylate antagonises the uricosuric effect of uricosuric agents; may increase adverse effect of alendronate. Dipyridamole: May antagonise the anticholinesterase effect of cholinesterase inhibitors. Increased risk of bleeding when used with warfarin. Antiplatelet effect of aspirin may be increased by antidepressants e.g. TCAs, selective serotonin reuptake inhibitors. Potentially Fatal: Salicylates may increase adverse effect of drotrecogin alfa. Dypyridamole may increase plasma levels and CV effects of adenosine. Ketorolac may enhance adverse effect of aspirin. Dipyridamole may increase therapeutic effect of regadenoson. Salicylates may increase the anticoagulant effect of vit K antagonists. Salicylates may increase the adverse effect of varicella virus-containing vaccines.

Adverse Effects

Side effects of Aspirin + Dipyridamole : >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%)

Mechanism of Action

Aspirin inhibits platelet aggregation by irreversible inhibition of platelet cyclooxygenase and thus the formation of thromboxane A2 in the platelets. Dipyridamole inhibits platelet aggregation by preventing the uptake of adenosine into platelets, endothelial cells and RBCs. The combination results in additive antiplatelet effects.