Dipyridamole / Aspirin

Pronunciation: DYE-pir-ID-a-mole/AS-pir-in
Class: Antiplatelet combination agent

Trade Names

Aggrenox
- Capsules, ER, oral dipyridamole ER 200 mg/aspirin 25 mg

Pharmacology

Antithrombotic action resulting from additive antiplatelet effects.

Slideshow: Top 10 Ways to Save on Your Medication Costs

Indications and Usage

Reduce the risk of stroke in patients who have had transient ischemia of the brain or complete ischemic stroke caused by thrombosis.

Contraindications

Hypersensitivity to any component of the product; allergy to NSAIDs; patients with asthma, rhinitis, and nasal polyps; children or teenagers with viral infections.

Dosage and Administration

PO Dipyridamole ER 200 mg/aspirin 25 mg twice daily. In the event of intolerable headaches during initial treatment, switch to dipyridamole ER 200 mg/aspirin 25 mg once daily at bedtime and low-dose aspirin in the morning. Patients should return to the usual regimen as soon as possible, usually within 1 wk.

General Advice

• Do not interchange with individual components of aspirin and dipyridamole tablets.
• Administer with or without food. Capsules should be swallowed whole and not crushed or chewed.

Storage/Stability

Store at 59° to 86°F. Protect from excessive moisture.

Drug Interactions

The effects of these agents may be decreased by aspirin. Avoid coadministration with uricosuric agents.

Metabolism of adenosine may be inhibited by dipyridamole, producing profound bradycardia. Adjust adenosine dose as necessary.

Patients who consume 3 or more alcoholic drinks daily may be at increased risk of bleeding because of aspirin coadministration. Regular or excessive use of alcohol should be avoided.

The pharmacologic and toxic effects of these agents may be increased by aspirin.

Concurrent use of aspirin can lead to high serum concentrations of acetazolamide (and toxicity) due to competition at the renal tubule for secretion. Carbonic anhydrase inhibitors may decrease the pharmacologic effects of aspirin. Use with caution.

Dipyridamole may counteract anticholinesterase effect, potentially aggravating myasthenia gravis.

The use of influenza virus vaccine, a live attenuated influenza virus vaccine, is contraindicated in children and adolescents receiving aspirin.

Children and adolescents receiving live varicella virus vaccine should avoid aspirin for 6 weeks following vaccination because of the possibility of developing Reye syndrome.

Adverse Reactions

Cardiovascular

Cardiac failure (2%); syncope (1%); angina pectoris, migraine (postmarketing).

CNS

Headache (39%); fatigue (6%); amnesia, asthenia, convulsions, malaise (2%); confusion, somnolence (1%); cerebral edema (postmarketing).

Dermatologic

Purpura (1%); alopecia, angioedema, rash, skin hemorrhages (eg, bruising, ecchymosis, hematoma), Stevens-Johnson syndrome (postmarketing).

EENT

Epistaxis (2%); hearing loss (postmarketing).

GI

Abdominal pain, dyspepsia (18%); nausea (16%); diarrhea (13%); vomiting (8%); melena, rectal hemorrhage (2%); anorexia, GI hemorrhage, hemorrhoid (1%); hematemesis, pancreatitis (postmarketing).

Genitourinary

Antepartum and postpartum bleeding, interstitial nephritis, lower birth weight infants, papillary necrosis, prolonged pregnancy and labor, proteinuria, stillbirths (postmarketing).

Hematologic

Hemorrhage (3%); anemia (2%); aplastic anemia, coagulopathy, DIC, pancytopenia, prolongation of PT, thrombocytopenia, thrombocytosis (postmarketing).

Hepatic

Hepatic failure, hepatitis (postmarketing).

Hypersensitivity

Acute anaphylaxis, hypersensitivity, laryngeal edema (postmarketing).

Metabolic

Dehydration, hyperkalemia, hypoglycemia, hypokalemia, metabolic acidosis, respiratory alkalosis (postmarketing).

Musculoskeletal

Arthralgia (6%); back pain (5%); arthritis (2%); arthrosis, myalgia (1%); rhabdomyolysis (postmarketing).

Respiratory

Coughing (2%); upper respiratory tract infection (1%); dyspnea, tachypnea (postmarketing).

Miscellaneous

Pain (6%); accidental injury (3%); neoplasm (2%); allergic vasculitis, chest pain, hypothermia, Reye syndrome (postmarketing).

Precautions

Pregnancy

Category D . Avoid use in the third trimester of pregnancy and during labor and delivery.

Lactation

Excreted in breast milk.

Children

Safety and efficacy not established; not recommended in pediatric patients.

Elderly

Greater sensitivity of some older individuals cannot be ruled out.

Hypersensitivity

Aspirin may cause severe urticaria, angioedema, or bronchospasm.

Renal Function

Avoid use in patients with severe renal failure (ie, glomerular filtration rate less than 10 mL/min).

Hepatic Function

Avoid use in patients with severe hepatic dysfunction.

Coagulation

Platelet function may be inhibited, increasing the risk of bleeding.

Coronary artery disease

Dipyridamole may precipitate or aggravate chest pain in patients with coronary artery disease.

Hepatic effects

Elevations of hepatic enzymes and hepatic failure have been reported with dipyridamole.

Hypotension

Use with caution because dipyridamole can produce peripheral vasodilation.

Peptic ulcer disease

Aspirin may cause gastric mucosal irritation and bleeding in patients with a history of active peptic ulcer disease; avoid use in these patients.

Overdosage

Symptoms

Convulsions, dizziness, flushes, hemorrhage, hypotension, metabolic acidosis, nausea, respiratory alkalosis, restlessness, sweating, tachycardia, tinnitus, vomiting, warm feeling, weakness.

Patient Information

• Advise patients not to crush or chew medication and to swallow the capsule whole with a full glass of water 2 times a day. Advise patients that if a dose is missed, they should not take 2 doses at once.
• Advise patients regarding risks of drinking alcohol while taking this medication.
• Inform patients that there is a general risk of bleeding, including intracranial and GI bleeding. Inform patients about the signs and symptoms of bleeding (including occult bleeding). Advise patients to notify their health care provider if they are prescribed any drug that may increase the risk of bleeding.
• Instruct patients to notify their health care provider if they are or become pregnant.
• Advise patients that headaches may occur upon initiation of therapy. If they experience intolerable headaches, they should contact their health care provider.

Copyright © 2009 Wolters Kluwer Health.