Dipyridamole

PERSANTINE

What it isAdenosine reuptake and PDE inhibitor; stroke prevention with aspirin, and pharmacological cardiac stress testing.

Why this oneWith aspirin it reduces recurrent stroke more than aspirin alone, and it is the vasodilator used for stress perfusion imaging.

What limits itHeadache is common and limits adherence. It can provoke ischemia by coronary steal; avoid in significant coronary disease.

FDA-approved for

FDA dosing	Population	Start	Target	Max
Prophylaxis of postoperative thromboembolic complications of cardiac valve replacement (adjunct to coumarin anticoagulants)	Adult	75–100 mg QID, adjunct to usual warfarin therapy	75–100 mg QID	100 mg QID

Renal Undefined

Hepatic Undefined

Use as adjunct to usual warfarin therapy; aspirin is not to be administered concomitantly with coumarin anticoagulants

Severe coronary artery disease (unstable angina, recent MI) — vasodilatory effect may aggravate chest pain
Hypotension — can produce peripheral vasodilation
Hepatic enzyme elevations and hepatic failure reported
Interrupt for 48 hr before pharmacologic stress testing with IV dipyridamole or other adenosinergic agents (adenosine, regadenoson)
Pediatric safety/effectiveness <12 yr not established

Dizziness (13.6%)
Abdominal distress (6.1%)
Headache (2.3%)
Rash (2.3%)
Also: diarrhea, vomiting, flushing, pruritus; rare angina pectoris and liver dysfunction
Rare hypersensitivity (rash, urticaria, bronchospasm, angioedema); increased surgical bleeding rarely

Pregnancy Animal studies up to ~25x human dose show no fetal harm; no adequate human studies — use only if clearly needed.

Lactation Excreted in human milk; use caution in nursing women.

NO BOXED WARNINGS

Principal riskHeadache; coronary steal in significant coronary disease

Cost, est. cash$4–$300/month

Generic entry1990

Therapeutic safety burden2 / 4

Overdose danger3 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk2 / 4

Legacy pregnancy categoryB

Defining liabilityGI or intracranial bleeding, especially with anticoagulants, NSAIDs or serotonergic antidepressants.

Box: minimal PK interactions