Dipyridamole Injection, USPRx only | Dipyridamole [West-Ward Pharmaceuticals Corp.] | BioPortfolio

12:41 EST 27th January 2019 | BioPortfolio
Note: While we endeavour to keep our records up-to-date one should not rely on these details being accurate without first consulting a professional. Click here to read our full medical disclaimer.

Dipyridamole is a coronary vasodilator described as 2,6 bis-(diethanolamino)-4,8 dipiperidino-pyrimido-(5,4-d) pyrimidine. The structural formula is:

 CHNO                                     MW 504.63

Dipyridamole Injection, USP is a sterile, odorless, pale yellow liquid which can be diluted in sodium chloride injection or dextrose injection for intravenous administration. Each mL contains 5 mg dipyridamole, USP, 50 mg polyethylene glycol 600 and 2 mg tartaric acid in Water for Injection, USP. pH 2.2-3.2; hydrochloric acid added for pH adjustment.

In a study of 10 patients with angiographically normal or minimally stenosed (less than 25% luminal diameter narrowing) coronary vessels, Dipyridamole Injection in a dose of 0.56 mg/kg infused over 4 minutes resulted in an average fivefold increase in coronary blood flow velocity compared to resting coronary flow velocity (range 3.8 to 7 times resting velocity). The mean time to peak flow velocity was 6.5 minutes from the start of the 4-minute infusion (range 2.5 to 8.7 minutes). Cardiovascular responses to the intravenous administration of Dipyridamole Injection when given to patients in the supine position include a mild but significant increase in heart rate of approximately 20% and mild but significant decreases in both systolic and diastolic blood pressure of approximately 2-8%, with vital signs returning to baseline values in approximately 30 minutes.

Dipyridamole is a coronary vasodilator in man. The mechanism of vasodilation has not been fully elucidated, but may result from inhibition of uptake of adenosine, an important mediator of coronary vasodilation. The vasodilatory effects of dipyridamole are abolished by administration of the adenosine receptor antagonist theophylline.

How dipyridamole-induced vasodilation leads to abnormalities in thallium distribution and ventricular function is also uncertain but presumably represents a “steal” phenomenon in which relatively intact vessels dilate and sustain enhanced flow, leaving reduced pressure and flow across areas of hemodynamically important coronary vascular constriction.

Plasma dipyridamole concentrations decline in a triexponential fashion following intravenous infusion of dipyridamole, with half-lives averaging 3-12 minutes, 33-62 minutes and 11.6-15 hours. Two minutes following a 0.568 mg/kg dose of Dipyridamole Injection administered as a 4-minute infusion, the mean dipyridamole serum concentration is 4.6 ± 1.3 mcg/mL. The average plasma protein binding of dipyridamole is approximately 99%, primarily to α-glycoprotein. Dipyridamole is metabolized in the liver to the glucuronic acid conjugate and excreted with the bile. The average total body clearance is 2.3-3.5 mL/min/kg, with an apparent volume of distribution at steady state of 1-2.5 L/kg and a central apparent volume of 3-5 liters.

Dipyridamole Injection is indicated as an alternative to exercise in thallium myocardial perfusion imaging for the evaluation of coronary artery disease in patients who cannot exercise adequately. In a study of about 1100 patients who underwent coronary arteriography and Dipyridamole Injection assisted thallium imaging, the results of both tests were interpreted blindly and the sensitivity and specificity of the dipyridamole thallium study in predicting the angiographic outcome were calculated. The sensitivity of the dipyridamole test (true positive dipyridamole divided by the total number of patients with positive angiography) was about 85%. The specificity (true negative divided by the number of patients with negative angiograms) was about 50%.

In a subset of patients who had exercise thallium imaging as well as dipyridamole thallium imaging, sensitivity and specificity of the two tests were almost identical.

Hypersensitivity to dipyridamole.

Serious adverse reactions associated with the administration of intravenous Dipyridamole Injection have included cardiac death, fatal and non-fatal myocardial infarction, ventricular fibrillation, symptomatic ventricular tachycardia, stroke, transient cerebral ischemia, seizures, anaphylactoid reaction and bronchospasm. There have been reported cases of asystole, sinus node arrest, sinus node depression and conduction block. Patients with abnormalities of cardiac impulse formation/conduction or severe coronary artery disease may be at increased risk for these events.

In a study of 3911 patients given intravenous dipyridamole as an adjunct to thallium myocardial perfusion imaging, two types of serious adverse events were reported: 1) four cases of myocardial infarction (0.1%), two fatal (0.05%) and two non-fatal (0.05%) and 2) six cases of severe bronchospasm (0.2%).  Although the incidence of these serious adverse events was small (0.3%, 10 of 3911), the potential clinical information to be gained through use of intravenous dipyridamole thallium imaging (see  INDICATIONS AND USAGE  noting the rate of false positive and false negative results) must be weighed against the risk to the patient. Patients with a history of unstable angina may be at a greater risk for severe myocardial ischemia. Patients with a history of asthma may be at a greater risk for bronchospasm during Dipyridamole Injection use.

When thallium myocardial perfusion imaging is performed with intravenous dipyridamole, parenteral aminophylline should be readily available for relieving adverse events such as bronchospasm or chest pain. Vital signs should be monitored during, and for 10-15 minutes following, the intravenous infusion of dipyridamole and an electrocardiographic tracing should be obtained using at least one chest lead. Should severe chest pain or bronchospasm occur, parenteral aminophylline may be administered by slow intravenous injection (50-100 mg over 30-60 seconds) in doses ranging from 50 to 250 mg. In the case of severe hypotension, the patient should be placed in a supine position with the head tilted down if necessary, before administration of parenteral aminophylline. If 250 mg of aminophylline does not relieve chest pain symptoms within a few minutes, sublingual nitroglycerin may be administered. If chest pain continues despite use of aminophylline and nitroglycerin, the possibility of myocardial infarction should be considered. If the clinical condition of a patient with an adverse event permits a one-minute delay in the administration of parenteral aminophylline, thallium-201 may be injected and allowed to circulate for one minute before the injection of aminophylline. This will allow initial thallium perfusion imaging to be performed before reversal of the pharmacologic effects of dipyridamole on the coronary circulation.


Oral maintenance theophylline and other xanthine derivatives such as caffeine may abolish the coronary vasodilatation induced by intravenous Dipyridamole Injection administration. This could lead to a false negative thallium imaging result (see  CLINICAL PHARMACOLOGY   –    Mechanism of Action ).

Myasthenia gravis patients receiving therapy with cholinesterase inhibitors may experience worsening of their disease in the presence of dipyridamole.

In studies in which dipyridamole was administered in the feed at doses of up to 75 mg/kg/day (9.4 times* the maximum recommended daily human oral dose) in mice (up to 128 weeks in males and up to 142 weeks in females) and rats (up to 111 weeks in males and females), there was no evidence of drug-related carcinogenesis. Mutagenicity tests of dipyridamole with bacterial and mammalian cell systems were negative. There was no evidence of impaired fertility when dipyridamole was administered to male and female rats at oral doses up to 500 mg/kg/day (63 times* the maximum recommended daily human oral dose). A significant reduction in number of corpora lutea with consequent reduction in implantations and live fetuses was, however, observed at 1250 mg/kg/day.    * Calculation based on assumed body weight of 50 kg.

Reproduction studies performed in mice and rats at daily oral doses of up to 125 mg/kg (15.6 times* the maximum recommended daily human oral dose) and in rabbits at daily oral doses of up to 20 mg/kg (2.5 times* the maximum recommended daily human oral dose) have revealed no evidence of impaired embryonic development due to dipyridamole. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human responses, this drug should be used during pregnancy only if clearly needed.    * Calculation based on assumed body weight of 50 kg.

Dipyridamole is excreted in human milk.

Safety and effectiveness in pediatric patients have not been established.

Adverse reaction information concerning intravenous Dipyridamole Injection is derived from a study of 3911 patients in which intravenous dipyridamole was used as an adjunct to thallium myocardial perfusion imaging and from spontaneous reports of adverse reactions and the published literature.

Serious adverse events (cardiac death, fatal and non-fatal myocardial infarction, ventricular fibrillation, asystole, sinus node arrest, symptomatic ventricular tachycardia, stroke, transient cerebral ischemia, seizures, anaphylactoid reaction and bronchospasm) are described above (see WARNINGS ).

In a study of 3911 patients, the most frequent adverse reactions were: chest pain/angina pectoris (19.7%), electrocardiographic changes (most commonly ST-T changes) (15.9%), headache (12.2%) and dizziness (11.8%).

Adverse reactions occurring in greater than 1% of the patients in the study are shown in the following table:

Less common adverse reactions occurring in 1% or less of the patients within the study included:

   Incidence (%) of Drug-Related Adverse Events
 Chest pain/angina pectoris  19.7
 Headache  12.2
 Dizziness  11.8
 Electrocardiographic Abnormalities/ST-T changes  7.5
 Electrocardiographic Abnormalities/Extrasystoles  5.2
 Hypotension  4.6
 Nausea  4.6
 Flushing  3.4
 Electrocardiographic Abnormalities/Tachycardia  3.2
 Dyspnea  2.6
 Pain Unspecified  2.6
 Blood Pressure Lability  1.6
 Hypertension  1.5
 Paresthesia  1.3
 Fatigue  1.2

Electrocardiographic abnormalities unspecified (0.8%), arrhythmia unspecified (0.6%), palpitation (0.3%), ventricular tachycardia (0.2%-see WARNINGS ), bradycardia (0.2%), myocardial infarction (0.1%–see WARNINGS ), AV block (0.1%), syncope (0.1%), orthostatic hypotension (0.1%), atrial fibrillation (0.1%), supraventricular tachycardia (0.1%), ventricular arrhythmia unspecified (0.03%–see WARNINGS ), heart block unspecified (0.03%), cardiomyopathy (0.03%), edema (0.03%).

Hypothesia (0.5%), hypertonia (0.3%), nervousness/anxiety (0.2%), tremor (0.1%), abnormal coordination (0.03%), somnolence (0.03%), dysphonia (0.03%), migraine (0.03%), vertigo (0.03%).

Dyspepsia (1%), dry mouth (0.8%), abdominal pain (0.7%), flatulence (0.6%), vomiting (0.4%), eructation (0.1%), dysphagia (0.03%), tenesmus (0.03%), appetite increase (0.03%).

Pharyngitis (0.3%), bronchospasm (0.2%–see WARNINGS ), hyperventilation (0.1%), rhinitis (0.1%), coughing (0.03%), pleural pain (0.03%).

Myalgia (0.9%), back pain (0.6%), injection site reaction unspecified (0.4%), diaphoresis (0.4%), asthenia (0.3%), malaise (0.3%), arthralgia (0.3%), injection site pain (0.1%), rigor (0.1%), earache (0.1%), tinnitus (0.1%), vision abnormalities unspecified (0.1%), dysgeusia (0.1%), thirst (0.03%), depersonalization (0.03%), eye pain (0.03%), renal pain (0.03%), perineal pain (0.03%), breast pain (0.03%), intermittent claudication (0.03%), leg cramping (0.03%). In additional postmarketing experience, there have been rare reports of allergic reaction including urticaria, pruritus, dermatitis and rash.

No cases of overdosage in humans have been reported. It is unlikely that overdosage will occur because of the nature of use (i.e., single intravenous administration in controlled settings). See WARNINGS .

The dose of intravenous Dipyridamole Injection as an adjunct to thallium myocardial perfusion imaging should be adjusted according to the weight of the patient. The recommended dose is 0.142 mg/kg/min (0.57 mg/kg total) infused over 4 minutes. Although the maximum tolerated dose has not been determined, clinical experience suggests that a total dose beyond 60 mg is not needed for any patient.Prior to intravenous administration, Dipyridamole Injection should be diluted in at least a 1:2 ratio with sodium chloride injection 0.45%, sodium chloride injection 0.9% or dextrose injection 5% for a total volume of approximately 20 to 50 mL. Infusion of undiluted dipyridamole may cause local irritation.

Thallium-201 should be injected within 5 minutes following the 4-minute infusion of dipyridamole.

Do not mix Dipyridamole Injection with other drugs in the same syringe or infusion container.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

Dipyridamole Injection, USP is available in:     10 mL (50 mg/10 mL) SINGLE DOSE vial packaged in 5s (NDC 0641-2569-44)

PROTECT FROM LIGHT: Keep covered in carton until time of use. Store between 15°-25°C (59°-77°F). Avoid freezing.

To report SUSPECTED ADVERSE REACTIONS, contact West-Ward Pharmaceutical Corp. at 1-877-845-0689, or the FDA at 1-800-FDA-1088 or

For Product Inquiry call 1-877-845-0689.

Manufactured by:


Revised: May 2011


Dipyridamole Injection, USP 50 mg/10 mL (5 mg/mL)10 mL VialNDC 0641-2569-41

Dipyridamole Injection, USP50 mg/10 mL (5 mg/mL)5 x 10 mL VialsNDC 0641-2569-44


West-Ward Pharmaceuticals Corp.

Active Ingredients


Drugs and Medications [33 Associated Drugs and Medications listed on BioPortfolio]

Dipyridamole [anazaohealth corporation]


Dipyridamole [rising pharmaceuticals, inc.]

Dipyridamole Tablets

Dipyridamole [carilion materials management]


Dipyridamole [ncs healthcare of ky, inc dba vangard labs]


Aspirin and extended-release dipyridamole [avkare, inc.]

Aspirin and Extended-release Dipyridamole Capsules These highlights do not include all the information needed to use ASPIRIN AND EXTENDED-RELEASE DIPYRIDAMOLE CAPSULES safely and effectively. See full...

Clinical Trials [38 Associated Clinical Trials listed on BioPortfolio]

Pharmacokinetics of Dipyridamole Administered as Aggrenox® (Dipyridamole Extended Release Plus Aspirin) Capsule Versus Dipyridamole Immediate Release Plus Aspirin Following Alteration of Stomach pH

Comparison of pharmacokinetics of dipyridamole administered as Aggrenox versus dipyridamole administered as the immediate release formulation plus aspirin, under conditions of reduced sto...

Enhancement of Postocclusive Reactive Hyperaemia by Dipyridamole

The purpose of this study is to determine whether dipyridamole enhances postocclusive reactive hyperaemia by increasing extracellular adenosine concentrations during ischemia and reperfusi...

Does Caffeine Reduce Dipyridamole-Induced Protection Against Ischemia-Reperfusion Injury?

The purpose of this project is to explore the interaction between caffeine and dipyridamole on ischemia-reperfusion injury in the forearm.

The Vascular Biology of Dipyridamole in Peripheral Arterial Disease (PAD)

This research study will evaluate the effects of aspirin and dipyridamole alone and in combination on the blood flow in the vessels of the legs. We will examine how these medications are ...

Does a Seven Day Treatment With Dipyridamole Induce Protection Against Ischemia-Reperfusion Injury?

This study is performed to determine whether a seven day treatment with dipyridamole (slow release, 200mg twice daily) can induce a protective effect against ischemia-reperfusion injury, a...

PubMed Articles [12 Associated PubMed Articles listed on BioPortfolio]

Bone Tissue Engineering in the Growing Calvaria Using Dipyridamole-Coated, Three-Dimensionally-Printed Bioceramic Scaffolds: Construct Optimization and Effects on Cranial Suture Patency.

Three-dimensionally-printed bioceramic scaffolds composed of β-tricalcium phosphate delivering the osteogenic agent dipyridamole can heal critically sized calvarial defects in skeletally mature trans...

A case report of dipyridamole stress-induced ST depression progressing to ST-elevation myocardial infarction despite intravenous aminophylline: steal, spasm, or something else?

Dipyridamole stress is commonly used for myocardial perfusion imaging and is generally safe. Myocardial ischaemia can occasionally occur and is classically thought to be due to coronary steal as a res...

The Anti-Platelet Anomaly: Aspirin/Dipyridamole-Induced Acute Pancreatitis.

Dipyridamole as a new drug to prevent Epstein-Barr virus reactivation.

Epstein-Barr virus (EBV) is a widely distributed gamma-herpesvirus that has been associated with various cancers mainly from lymphocytic and epithelial origin. Although EBV-mediated oncogenesis has be...

Fatal Spontaneous Retropharyngeal Hematoma with Airway Obstruction in the Setting of Treatment with Dipyridamole.

We report a fatal case of airway obstruction caused by spontaneous retropharyngeal hematoma (RH) in the setting of treatment with dipyridamole. A 90-year-old woman presented with cervical swelling, ne...

Quick Search

Relevant Topics

Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...

Cardiovascular disease (CVD)
Acute Coronary Syndromes (ACS) Blood Cardiovascular Dialysis Hypertension Stent Stroke Vascular Cardiovascular disease (CVD) includes all the diseases of the heart and circulation including coronary heart disease (angina...

Drugs and Medication Quicklinks

Searches Linking to this Drug Record