Antiplatelet — Phosphodiesterase Inhibitor / Adenosine Uptake Inhibitor Pregnancy: Use with caution — limited data; dipyridamole has been used in pregnancy for thrombosis prevention in prosthetic valves; aspirin component contraindicated near term at standard doses.

Dipyridamole (Secondary Stroke Prevention)

Brand names: Persantin Retard (with aspirin), Asasantin Retard (combined product)

Adult dose

Dose: Secondary stroke/TIA prevention: dipyridamole MR 200 mg twice daily (combined with aspirin 25 mg twice daily as Asasantin Retard). Standalone: Persantin Retard 200 mg BD

Route: Oral (modified-release capsule)

Frequency: Twice daily

Max: 200 mg twice daily

Mechanism: inhibits phosphodiesterase (increases cAMP/cGMP in platelets) AND blocks adenosine reuptake (vasodilation, platelet inhibition). Used in secondary prevention of stroke/TIA — NICE NG128 recommends aspirin + dipyridamole MR for 2 years post-TIA or ischaemic stroke, then clopidogrel monotherapy. Also used in cardiac stress testing (pharmacological stress with adenosine augmentation).

Paediatric dose

Dose: 1–5 mg/day/kg

Route: Oral

Frequency: Three times daily

Max: Adult dose

Paediatric use: Kawasaki disease antiplatelet therapy, prosthetic heart valves — specialist paediatric cardiology guidance. BNFc.

Dose adjustments

Renal

No dose adjustment required.

Hepatic

No dose adjustment required for mild-moderate hepatic impairment.

Paediatric weight-based calculator

Patient weight (kg)

Paediatric use: Kawasaki disease antiplatelet therapy, prosthetic heart valves — specialist paediatric cardiology guidance. BNFc.

Clinical pearls

ESPS-2 trial (Diener et al. NEJM 1996): aspirin + extended-release dipyridamole vs aspirin alone or dipyridamole alone in secondary stroke prevention — combination reduced stroke recurrence by 37% vs placebo, 23% vs aspirin alone. PRoFESS trial (NEJM 2008): aspirin+dipyridamole vs clopidogrel — non-inferior for recurrent stroke; similar bleeding
NICE NG128 post-stroke protocol: aspirin 300 mg loading day 1 → aspirin 75 mg + dipyridamole MR 200 mg BD for 2 years → then clopidogrel 75 mg monotherapy indefinitely. This sequential protocol is evidence-based and cost-effective
Headache management: the most common reason for discontinuation; advise patients to take first dose at bedtime; headache usually resolves within 2 weeks as tolerance develops. Starting with one capsule once daily for 1 week before twice-daily dosing can improve tolerability

Contraindications

Hypersensitivity to dipyridamole
Severe coronary artery disease (dipyridamole-induced vasodilation can cause coronary steal — caution with stress testing protocols)
Decompensated heart failure

Side effects

Headache (common — vasodilatory; often resolves after 1–2 weeks; start with single evening dose to reduce impact)
Dizziness
GI upset (nausea, diarrhoea)
Flushing
Coronary steal (IV administration — used in stress testing; can cause angina)
Bleeding (antiplatelet effect — additive with aspirin)

Interactions

Adenosine (markedly potentiates effects — conduction block; must halve adenosine dose if dipyridamole given in last 24h)
Anticoagulants (additive bleeding risk)
Antihypertensives (additive hypotension from vasodilatory effect)

Monitoring

Blood pressure (vasodilatory hypotension — monitor on initiation)
Headache severity and tolerability
Bleeding signs
Adherence (headache commonly leads to non-adherence)

Reference: BNFc; BNF 90; ESPS-2 Trial (Diener et al. JNRS 1996); PRoFESS Trial (NEJM 2008); NICE NG128 (Stroke and TIA); MHRA SPC Persantin Retard. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways