Issues for Surgery
Risk of ischaemic event if omitted.
Advice in the Perioperative period
Elective and Emergency Surgery
Dipyridamole Alone or in Combination with Aspirin
Combination product: -
NB: For patients taking aspirin - also see Aspirin monograph.
Dipyridamole in Combination with Oral Anticoagulation
NB: For patients taking warfarin – also see Warfarin monograph.
NB: For patients taking DOACs – also see Direct Oral Anticoagulant (DOACs) monograph.
Resume usual treatment post-operatively, unless otherwise advised by a Haematologist.
Interaction(s) with Common Anaesthetic Agents
Dipyridamole can increase the risk of hypotension when used concomitantly with inhalational or intravenous anaesthetics1.
Interaction(s) with other Common Medicines used in the Perioperative Period
Dipyridamole increases the plasma level and cardiovascular effects of adenosine1, 2, 3, 4. The adenosine bolus dose necessary to convert supraventricular tachycardia (SVT) to sinus rhythm is reduced by about fourfold2. Avoid or use initial bolus adenosine of 500 mcg or 1 mg in SVT2.
Dipyridamole can increase the risk of hypotension when used concomitantly with droperidol or prochlorperazine1.
Low Molecular Weight Heparin (LMWH) / Unfractionated Heparin (UFH)
LMWH / UFH is predicted to increase the risk of bleeding events when given with dipyridamole2, 3, 4.
Aspirin (contained in Molita®) has been show to increase the risk of bleeding when given with anticoagulants (e.g. heparin)5.
Concomitant use of corticosteroids with Molita® can increase the risk of gastrointestinal side effects due to the aspirin component5.
Non-Steroidal Anti-inflammatory Drugs (NSAIDs)
Concomitant use of NSAIDs with dipyridamole can increase the risk of bleeding1.
Concomitant use of NSAIDs with Molita® can increase the risk of gastrointestinal side effects due to the aspirin component5.
Drugs that Reduce Gastric pH
Proton pump inhibitors (PPIs) are predicted to decrease the absorption of dipyridamole (immediate release tablets)1. It is expected that other drugs that raise the gastric pH (e.g. histamine H2-antagonists [H2RAs], antacids) may reduce the bioavailability of dipyridamole (from tablets or suspension formulations)2, 3. The clinical significance of this interaction is unclear2. Single pre-operative doses of a PPI or H2RA should not pose a problem, but consider the interaction if prolonged use of PPI/H2RA is required post-operatively in patients not previously taking these medicines.
NB: Modified-release (MR) preparations of dipyridamole (that are buffered) do not appear to be affected2. Most patients being treated with dipyridamole are likely to be on the MR preparation. The standard release preparations are rarely used anymore due to a change in the evidence base.
Daily use of dipyridamole does not alter bleeding times or laboratory platelet aggregation; nor does it appear to increase blood loss significantly during surgical procedures. Hence, unless the bleeding risk from the procedure is deemed exceptionally high, dipyridamole need not be stopped perioperatively6.
Addition of dipyridamole to aspirin does not increase the incidence of bleeding events4, 5. When dipyridamole was administered concomitantly with warfarin, bleeding was no greater in frequency or severity than that observed when warfarin was administered alone4, 5.