Aspirin and Extended – Release Dipyridamole

Aspirin and Extended-Release Dipyridamole Capsule is indicated to reduce the risk of stroke in patients who have had transient ischemia of the brain or completed ischemic stroke due to thrombosis. Aspirin and Extended-Release Dipyridamole Capsule is a combination of aspirin and dipyridamole, antiplatelet agents, indicated to reduce the risk of stroke in patients who have had transient ischemia of the brain or completed ischemic stroke due to thrombosis ( 1 )

25 mg/200 mg capsules are imprinted in black with ‘PAR’ on the cap and ‘730’ on the body, containing yellow colored extended-release pellets incorporating dipyridamole and a white to off white, film coated, circular, bi-convex tablet incorporating immediate-release aspirin. Capsule: 25 mg aspirin/200 mg extended-release dipyridamole ( 3 )

Hypersensitivity to any product ingredients ( 4.1 ) Patients with known allergy to NSAIDs ( 4.2 ) Patients with the syndrome of asthma, rhinitis, and nasal polyps ( 4.2 )

4.1 Hypersensitivity Aspirin and extended-release dipyridamole is contraindicated in patients with known hypersensitivity to any of the product components.

4.2 Allergy Aspirin is contraindicated in patients with known allergy to nonsteroidal anti-inflammatory drug (NSAID) products and in patients with the syndrome of asthma, rhinitis, and nasal polyps. Aspirin may cause severe urticaria, angioedema or bronchospasm.

4.3 Reye Syndrome Do not use aspirin in children or teenagers with viral infections because of the risk of Reye syndrome.

Aspirin and extended-release dipyridamole capsules increases the risk of bleeding ( 5.1 ) Avoid use in patients with severe hepatic or renal insufficiency ( 5.2 , 5.3 ) Interrupt aspirin and extended-release dipyridamole capsules 48 hours before using intravenous dipyridamole or other adenosinergic agents for stress testing ( 5.6 , 7.1 )

5.1 Risk of Bleeding Aspirin and extended-release dipyridamole increases the risk of bleeding. Risk factors for bleeding include the use of other drugs that increase the risk of bleeding (e.g., anticoagulants, antiplatelet agents, heparin, anagrelide, fibrinolytic therapy, and chronic use of NSAIDs) [see Drug Interactions ( 7.1 )]. Intracranial Hemorrhage In European Stroke Prevention Study-2 (ESPS2), the annualized event rate for intracranial hemorrhage was 0.39%/year in the aspirin and extended-release dipyridamole group, 0.26%/year in the extended-release dipyridamole (ER-DP) group, 0.24%/year in the aspirin (ASA) group, and 0.29%/year in the placebo groups. Gastrointestinal (GI) Side Effects GI side effects include stomach pain, heartburn, nausea, vomiting, and gross GI bleeding. Although minor upper GI symptoms, such as dyspepsia, are common and can occur anytime during therapy, physicians should remain alert for signs of ulceration and bleeding, even in the absence of previous GI symptoms. Inform patients about the signs and symptoms of GI side effects and what steps to take if they occur . In ESPS2, the annualized event rate for gastrointestinal bleeding was 2.97%/year in the aspirin and extended-release dipyridamole group, 1.58%/year in the extended-release dipyridamole group, 2.06%/year in the aspirin group, and 1.40%/year in the placebo groups. Peptic Ulcer Disease Avoid using aspirin in patients with a history of active peptic ulcer disease, which can cause gastric mucosal irritation and bleeding. Alcohol Warning Because aspirin and extended-release dipyridamole contains aspirin, counsel patients who consume three or more alcoholic drinks every day about the bleeding risks involved with chronic, heavy alcohol use while taking aspirin.

5.2 Renal Failure Avoid aspirin in patients with severe renal failure (glomerular filtration rate less than 10 mL/minute) [see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 )].

5.3 Hepatic Insufficiency Elevations of hepatic enzymes and hepatic failure have been reported in association with dipyridamole administration [see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 )].

5.4 Coronary Artery Disease Dipyridamole has a vasodilatory effect. Chest pain may be precipitated or aggravated in patients with underlying coronary artery disease who are receiving dipyridamole. For stroke or TIA patients for whom aspirin is indicated to prevent recurrent myocardial infarction (MI) or angina pectoris, the aspirin in this product may not provide adequate treatment for the cardiac indications.

5.5 Hypotension Dipyridamole produces peripheral vasodilation, which can exacerbate pre-existing hypotension.

5.6 Stress Testing with Intravenous Dipyridamole and Other Adenosinergic Agents Clinical experience suggests that patients being treated with aspirin and extended-release dipyridamole capsules who also require pharmacological stress testing with intravenous dipyridamole or other adenosinergic agents (e.g., adenosine, regadenoson) should interrupt aspirin and extended-release dipyridamole capsules for 48 hours prior to stress testing [see Drug Interactions ( 7.1 )] . Intake of aspirin and extended-release dipyridamole capsules within 48 hours prior to stress testing with intravenous dipyridamole or other adenosinergic agents may increase the risk for cardiovascular side effects of these agents and may impair the sensitivity of the test.

5.7 General Aspirin and extended-release dipyridamole capsules are not interchangeable with the individual components of aspirin and dipyridamole tablets.

The following adverse reactions are discussed elsewhere in the labeling: Hypersensitivity [see Contraindications ( 4.1 ) ] Allergy [see Contraindications ( 4.2 ) ] Risk of Bleeding [see Warnings and Precautions ( 5.1 )] The most frequently reported adverse reactions (>10% and greater than placebo) were headache, dyspepsia, abdominal pain, nausea, and diarrhea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Par Health at 1-800-828-9393 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The efficacy and safety of aspirin and extended-release dipyridamole was established in the European Stroke Prevention Study-2 (ESPS2). ESPS2 was a double-blind, placebo-controlled study that evaluated 6602 patients over the age of 18 years who had a previous ischemic stroke or transient ischemic attack within ninety days prior to entry. Patients were randomized to either aspirin and extended-release dipyridamole, aspirin, ER-DP, or placebo [see Clinical Studies ( 14 )] ; primary endpoints included stroke (fatal or nonfatal) and death from all causes. This 24-month, multicenter, double-blind, randomized study (ESPS2) was conducted to compare the efficacy and safety of aspirin and extended-release dipyridamole with placebo, extended-release dipyridamole alone and aspirin alone. The study was conducted in a total of 6602 male and female patients who had experienced a previous ischemic stroke or transient ischemia of the brain within three months prior to randomization. Table 1 presents the annualized event rate for adverse events that occurred in 1%/year or more of patients treated with aspirin and extended-release dipyridamole where the incidence was also at least 1%/year greater than in those patients treated with placebo. There is no clear benefit of the dipyridamole/aspirin combination over aspirin with respect to safety. Table 1 Incidence of Adverse Events in ESPS2 a Individual Treatment Group Body System/Preferred Term Aspirin and Extended-Release Dipyridamole n (%/year) b ER-DP Alone n (%/year) b ASA Alone n (%/year) b Placebo n (%/year) b Total Number of Patients 1,650 1,654 1,649 1,649 Central and Peripheral Nervous System Disorders Headache 647 (28.25) 634 (27.91) 558 (22.10) 543 (22.29) Gastrointestinal System Disorders Dyspepsia 303 (13.23) 288 (12.68) 299 (11.84) 275 (11.29) Abdominal Pain 289 (12.62) 255 (11.22) 262 (10.38) 239 (9.81) Nausea 264 (11.53) 254 (11.18) 210 (8.32) 232 (9.53) Diarrhea 210 (9.17) 257 (11.31) 112 (4.44) 161 (6.61) Vomiting 138 (6.03) 129 (5.68) 101 (4.00) 118 (4.84) Platelet, Bleeding and Clotting Disorders Hemorrhage NOS 52 (2.27) 24 (1.06) 46 (1.82) 24 (0.99) a Reported by ≥1%/year of patients during aspirin and extended-release dipyridamole treatment where the incidence was at least 1%/year greater than in those treated with placebo. b Annual event rate per 100 pt-years = 100* number of subjects with event/subject-years. Subject-years is defined as cumulative number of days on treatment divided by 365.25. Note: ER-DP = extended-release dipyridamole 200 mg; ASA = aspirin 25 mg. The dosage regimen for all treatment groups is BID. NOS = not otherwise specified. Discontinuation due to adverse events in ESPS2 was 25% for aspirin and extended-release dipyridamole, 25% for extended-release dipyridamole, 19% for aspirin, and 21% for placebo (refer to Table 2). Table 2 Incidence of Adverse Events that Led to the Discontinuation of Treatment a Treatment Groups Aspirin and Extended-Release Dipyridamole n (%/year) b ER-DP n (%/year) b ASA n (%/year) b Placebo n (%/year) b Total Number of Patients 1,650 1,654 1,649 1,649 Patients with at least one Adverse Event that led to treatment discontinuation 417 (18.21) 419 (18.44) 318 (12.59) 352 (14.45) Headache 165 (7.20) 166 (7.31) 57 (2.26) 69 (2.83) Nausea 91 (3.97) 95 (4.18) 51 (2.02) 53 (2.18) Abdominal Pain 74 (3.23) 64 (2.82) 56 (2.22) 52 (2.13) Vomiting 53 (2.31) 52 (2.29) 28 (1.11) 24 (0.99) a Reported by ≥1%/year of patients during aspirin and extended-release dipyridamole treatment where the incidence was at least 1%/year greater than in those treated with placebo. b Annual event rate per 100 pt-years = 100* number of subjects with event/subject-years. Subject-years is defined as cumulative number of days on treatment divided by 365.25. Note: ER-DP = extended-release dipyridamole 200 mg; ASA = aspirin 25 mg. The dosage regimen for all treatment groups is BID. Headache was most notable in the first month of treatment.

6.2 Post Marketing Experience The following is a list of additional adverse reactions that have been reported either in the literature or are from post-marketing spontaneous reports for either dipyridamole or aspirin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate reliably their frequency or establish a causal relationship to drug exposure. Decisions to include these reactions in labeling are typically based on one or more of the following factors: (1) seriousness of the reaction, (2) frequency of reporting, or (3) strength of causal connection to aspirin and extended-release dipyridamole. Body as a Whole: Hypothermia, chest pain, allergic reaction, syncope Cardiovascular: Angina pectoris, hypotension Central Nervous System: Cerebral edema, dizziness, cerebral hemorrhage, intracranial hemorrhage, subarachnoid hemorrhage Fluid and Electrolyte: Hyperkalemia, metabolic acidosis, respiratory alkalosis, hypokalemia Gastrointestinal: Pancreatitis, Reye syndrome, hematemesis, gastritis, ulceration and perforation, hemorrhage rectum, melena, GI hemorrhage Hearing and Vestibular Disorders: Hearing loss Heart Rate and Rhythm Disorders: Tachycardia, palpitation Immune System Disorders: Hypersensitivity, acute anaphylaxis, laryngeal edema Liver and Biliary System Disorders: Hepatitis, hepatic failure, cholelithiasis, jaundice, hepatic function abnormal Musculoskeletal : Rhabdomyolysis, myalgia Metabolic and Nutritional Disorders: Hypoglycemia, dehydration Platelet, Bleeding and Clotting Disorders: Prolongation of the prothrombin time, disseminated intravascular coagulation, coagulopathy, thrombocytopenia, hematoma, gingival bleeding, epistaxis, purpura Psychiatric Disorders: Confusion, agitation Respiratory: Tachypnea, dyspnea, hemoptysis Skin and Appendages Disorders: Rash, alopecia, angioedema, Stevens-Johnson syndrome, skin hemorrhages such as bruising, ecchymosis, and hematoma, pruritus, urticaria, and drug reaction with eosinophilia and systemic symptoms (DRESS) Urogenital: Interstitial nephritis, papillary necrosis, proteinuria, renal insufficiency and failure, hematuria Vascular (Extracardiac) Disorders: Allergic vasculitis, flushing Other Adverse Events: Anorexia, aplastic anemia, migraine, pancytopenia, thrombocytosis.

Co-administration with anticoagulants, antiplatelets, or NSAIDs can increase risk of bleeding ( 7.1 ) Decreased renal function can occur with co-administration with NSAIDs ( 7.1 )

7.1 Drug Interaction Study Information Obtained From Literature Adenosinergic agents (e.g., adenosine, regadenoson) Dipyridamole has been reported to increase the plasma levels and cardiovascular effects of adenosine. Adjustment of adenosine dosage may be necessary. Dipyridamole also increases the cardiovascular effects of regadenoson, an adenosine A 2A -receptor agonist. The potential risk of cardiovascular side effects with intravenous adenosinergic agents may be increased during the testing period when dipyridamole is not held 48 hours prior to stress testing. Angiotensin Converting Enzyme (ACE) Inhibitors Because of the indirect effect of aspirin on the renin-angiotensin conversion pathway, the hyponatremic and hypotensive effects of ACE inhibitors may be diminished by concomitant administration of aspirin. Acetazolamide Concurrent use of aspirin and acetazolamide can lead to high serum concentrations of acetazolamide (and toxicity) due to competition at the renal tubule for secretion. Anticoagulants and Antiplatelets Patients taking aspirin and extended-release dipyridamole in combination with anticoagulants, antiplatelets, or any substance impacting coagulation are at increased risk for bleeding. Aspirin can displace warfarin from protein binding sites, leading to prolongation of both the prothrombin time and the bleeding time. Aspirin can increase the anticoagulant activity of heparin, increasing bleeding risk. A nagrelide Patients taking aspirin in combination with anagrelide are at an increased risk of bleeding. Anticonvulsants Salicylic acid can displace protein-bound phenytoin and valproic acid, leading to a decrease in the total concentration of phenytoin and an increase in serum valproic acid levels. Beta Blockers The hypotensive effects of beta blockers may be diminished by the concomitant administration of aspirin due to inhibition of renal prostaglandins, leading to decreased renal blood flow and salt and fluid retention. Cholinesterase Inhibitors Dipyridamole may counteract the anticholinesterase effect of cholinesterase inhibitors, thereby potentially aggravating myasthenia gravis. Diuretics The effectiveness of diuretics in patients with underlying renal or cardiovascular disease may be diminished by the concomitant administration of aspirin due to inhibition of renal prostaglandins, leading to decreased renal blood flow and salt and fluid retention. Methotrexate Salicylate can inhibit renal clearance of methotrexate, leading to bone marrow toxicity, especially in the elderly or renal impaired. Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) The concurrent use of aspirin with other NSAIDs may increase bleeding or lead to decreased renal function. Oral Hypoglycemics Moderate doses of aspirin may increase the effectiveness of oral hypoglycemic drugs, leading to hypoglycemia. Uricosuric Agents (probenecid and sulfinpyrazone) Salicylates antagonize the uricosuric action of uricosuric agents.

The antithrombotic action of aspirin and extended-release dipyridamole is the result of the additive antiplatelet effects of dipyridamole and aspirin. Dipyridamole Dipyridamole inhibits the uptake of adenosine into platelets, endothelial cells and erythrocytes in vitro and in vivo ; the inhibition occurs in a dose-dependent manner at therapeutic concentrations (0.5 to 1.9 mcg/mL). This inhibition results in an increase in local concentrations of adenosine which acts on the platelet A 2 -receptor thereby stimulating platelet adenylate cyclase and increasing platelet cyclic-3',5'-adenosine monophosphate (cAMP) levels. Via this mechanism, platelet aggregation is inhibited in response to various stimuli such as platelet activating factor (PAF), collagen and adenosine diphosphate (ADP). Dipyridamole inhibits phosphodiesterase (PDE) in various tissues. While the inhibition of cAMP-PDE is weak, therapeutic levels of dipyridamole inhibit cyclic-3',5'­-guanosine monophosphate-PDE (cGMP-PDE), thereby augmenting the increase in cGMP produced by EDRF (endothelium-derived relaxing factor, now identified as nitric oxide). Aspirin Aspirin inhibits platelet aggregation by irreversible inhibition of platelet cyclooxygenase and thus inhibits the generation of thromboxane A 2 , a powerful inducer of platelet aggregation and vasoconstriction.