Adult Dosing
Thallium myocardial perfusion imaging
- 0.142 mg/kg/min (0.57 mg/kg total) IV over 4 mins, Max: 60 mg/procedure
- Inject thallium within 5 mins after the 4-min infusion of dipyridamole
Note:
- Dilute dipyridamole injection in 1:2 ratio with 0.45% or 0.9% sodium chloride, or 5% dextrose for a total volume of approximately 20 to 50 mL
Pediatric Dosing
- Safety and effectiveness in the pediatric patient have not been established
[Outline]
- Intravenous dipyridamole causes serious adverse reactions including cardiac death, fatal and nonfatal myocardial infarction, ventricular fibrillation, symptomatic ventricular tachycardia, stroke, transient cerebral ischemia, seizures, anaphylactoid reaction and bronchospasm. Patients with severe coronary artery disease and history of asthma are at greater risk
- Asystole, sinus node arrest, sinus node depression and conduction block have been reported with dipyridamole infusion. Use cautiously in patients with abnormalities of cardiac impulse formation/conduction
- As dipyridamole infusion causes serious adverse events, the potential clinical information to be gained through use of intravenous dipyridamole thallium imaging must be weighed against the risk to the patient
- Keep parenteral aminophylline readily available while performing thallium myocardial perfusion imaging with intravenous dipyridamole. If severe chest pain or bronchospasm occurs, administer aminophylline by slow intravenous injection in doses ranging from 50 to 250 mg. If chest pain is not relieved within a few minutes of aminophylline administration, give sublingual nitroglycerin and if still chest pain continues, the possibility of myocardial infarction should be considered
- Monitor vital signs during, and for 10 to 15 minutes following, the intravenous infusion of dipyridamole and obtain electrocardiographic tracing using at least one chest lead
- If hypotension occurs, place the patient in supine position with the head tilted down
- Inject thallium-201 and allow to circulate for one minute before the injection of aminophylline if the clinical condition of a patient with an adverse event permits a one-minute delay in the administration of parenteral aminophylline. This will allow initial thallium perfusion imaging to be performed before reversal of the pharmacologic effects of dipyridamole on the coronary circulation
Cautions: Use cautiously in
- Severe coronary artery disease
- Cardiac impulse formation/conduction abnormalities
- History of unstable angina
- History of asthma
Pregnancy Category:B
Breastfeeding: As dipyridamole is excreted in human milk, manufacturer advises caution while administering to nursing woman.
