dipyridamole (Rx)

>10%

Chest pain (20%)

Angina exacerbation, IV (19.7%)

Abnormal ECG (15.9%)

Headache, IV (12.2%)

Dizziness (12%)

1-10%

ST-T changes (7.5%)

Abdominal discomfort, oral (6.1%)

Extrasystole (5%)

Nausea, IV (4.6%)

Hypotension, IV (4.6%)

Flushing (3.4%)

Generalized pain (2.6%)

Headache, oral (2.3%)

Frequency Not Defined

Myocardial infarction (rare)

Ventricular arrhythmia (rare)

Bronchospasm (rare)

Dyspnea

Contraindications

Hypersensitivity

Thrombocytopenia

Cautions

FDA approval for chronic angina withdrawn (not useful according to most experts)

Dipyridamole has a vasodilatory effect and should be used with caution in patients with severe coronary artery disease (eg, unstable angina or recently sustained myocardial infarction); chest pain may be aggravated in patients with underlying coronary artery disease who are receiving drug

Elevations of hepatic enzymes and hepatic failure reported in association with therapy administration

Drug should be used with caution in patients with hypotension since it can produce peripheral vasodilation

Stress Testing

• Clinical experience suggests that patients being treated who also require pharmacological stress testing with intravenous dipyridamole or other adenosinergic agents (e.g. adenosine, regadenoson) should interrupt therapy for 48 hours prior to stress testing
• Intake of drug within 48 hours prior to stress testing with intravenous dipyridamole or other adenosinergic agents may increase risk for cardiovascular side effects of these agents and may impair the sensitivity of test

Pregnancy Category: B

Lactation: 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.

Mechanism of Action

Non-nitrate coronary vasodilator

• Inhibition of RBC uptake of adenosine thereby inhibiting platelet reactivity
• Phosphodiesterase inhibition increasing cAMP in platelet, OR
• Inhibition of Thromboxane A2 formation (vasoconstrictor and a stimulator of platelet activation)

Pharmacokinetics

Half-life elimination: 10-12hr

Peak time: 2-2.5 hr

Onset: 24 min

Duration: 3 hr

Protein Bound: 91-99%

Vd: 2-3 L/kg

Clearance: 2.3-3.5 mL/min/kg

Excretion: Feces

Dialyzable: No

Metabolism: Liver