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2.9 Antiplatelet drugs

Aspirin tablets
Cangrelor injection – see note
Dipyridamole MR capsules
Clopidogrel tablets - refer to NICE TA 210
Prasugrel tablets - see note below re: loading doses; refer to NICE TA 317
Ticagrelor tablets - refer to NICE TA 236 and NICE TA 420
Tirofiban Infusion

Patients with unstable angina or NSTEMI who have intermediate/high risk of adverse cardiovascular events and who are for angiography within 96 hours (see NICE CG 94: Unstable Angina and NSTEMI).

Print Version of Tirofiban Prescription Sheet and Flow Diagram


Abciximab infusion - for emergency Percutaneous Coronary Intervention (Cardiologist only).

(patients at intermediate /high risk of adverse cardiovascular events - see NICE CG 94: Unstable Angina and NSTEMI)


1. No conventionally used prophylactic aspirin regime seems free of the risk of peptic ulcer complications. Therefore,  the dose of prophylactic aspirin should be maintained as low as possible. The National Service Framework for Coronary Heart Disease recommends 75mg daily.

2. There is no evidence that enteric coated aspirin has a lower GI bleeding risk. It is more expensive and may be poorly absorbed.

3. Clopidogrel is recommended as an option to prevent occlusive vascular events:


  • for people who have had an ischaemic stroke or who have peripheral arterial disease or multivascular disease or

  • for people who have had a myocardial infarction only if aspirin is contraindicated or not tolerated.


4. Modified-release dipyridamole in combination with aspirin is recommended as an option to prevent occlusive vascular events:


  • for people who have had a transient ischaemic attack or

  • for people who have had an ischaemic stroke only if clopidogrel is contraindicated or not tolerated.


Modified-release dipyridamole alone is recommended as an option to prevent occlusive vascular events:


  • for people who have had an ischaemic stroke only if aspirin and clopidogrel are contraindicated or not tolerated or

  • for people who have had a transient ischaemic attack only if aspirin is contraindicated or not tolerated.


5. Clopidogrel is listed for use in patients with documented hypersensitivity to aspirin. Clopidogrel may also be used in the treatment of Acute Coronary Syndrome in combination with aspirin for up to 12 months (no evidence of benefit beyond 12 months) and also after STEMI for 4 weeks post MI.

6. Clopidogrel has been associated with rare cases of acquired haemophilia. See DSU December 2013

Clopidogrel and Proton Pump Inhibitors

The available evidence for an interaction between clopidogrel and PPIs is not completely consistent. Pharmacokinetic, pharmacodynamic, and some clinical outcome data suggest a significant interaction for omeprazole, and there is also some evidence in relation to esomeprazole.However, the findings of clinical studies for the other PPIs are inconsistent.

In light of the most recent evidence, the previous advice (to avoid all PPIs unless absolutely necessary for patients taking clopidogrel) is no longer considered necessary. Nevertheless, as a precaution, concomitant use of clopidogrel with
omeprazole or esomeprazole should be discouraged. The current evidence does not support extending this advice to other PPIs.

However, because it is not possible to completely exclude a possible interaction with these PPIs on the basis of available data, the potential risk of a slight reduction in efficacy of clopidogrel should be weighed against the potential
gastrointestinal benefit of the PPI.

  • Concomitant use of clopidogrel and omeprazole or esomeprazole is to be discouraged unless considered essential.
  • Doctors should check whether patients who are taking clopidogrel are also buying over-the-counter omeprazole and consider whether other gastrointestinal therapies would be more suitable.
  • Consider PPIs other than omeprazole or esomeprazole in patients who are taking clopidogrel (e.g. lower doses of lansoprazole or pantoprazole). Other gastrointestinal therapy such as H2 blockers (except cimetidine) or antacids may be more suitable in some patients..
  • Discourage concomitant use of other known CYP2C19-inhibiting medicines with clopidogrel because these are expected to have a similar effect to omeprazole and esomeprazole (CYP2C19 inhibitors include fluvoxamine, fluoxetine, moclobemide, voriconazole, fluconazole, ticlopidine, ciprofloxacin, cimetidine, carbamazepine, oxcarbazepine, and chloramphenicol).
  • A UKMi Q&A 'Do proton pump inhibitors reduce the clinical efficacy of clopidogrel' is available here.

Prasugrel / Ticagrelor

7. Prasugrel has been rarely associated with reports of serious hypersensitivity reactions including, very rarely, angioedema; some of which occurred in patients with a history of hypersensitivity to clopidogrel. Healthcare professionals should be aware of this risk when prescribing prasugrel. See Drug Safety Update May 2011.

Patients who have a stent thrombosis whilst on clopidogrel (or are intolerant of clopidogrel) should receive prasugrel (duration and dose at the discretion of the cardiologist).

For primary PCI, in STEMI patients the loading dose for prasugrel is 60mg. For patients who have ever had a CVA/TIA or cerebral bleed, ticagrelor 180mg or clopidogrel 600mg will be used.

Maintenance doses are: prasugrel 10mg daily, ticagrelor 90mg twice daily or clopidogrel 75mg daily.

Following a PCI, patients with a STEMI will now receive the anti-platelet drug prasugrel (alongside aspirin) for a full 12 months. After a loading dose of 60 mg, the patient will receive prasugrel 10 mg daily.  At the same time, ticagrelor (also with aspirin) for 12 months has been approved as a second-line agent in STEMI for patients who have contraindications to prasugrel i.e. patients at increased risk of bleeding e.g. those older than 75 years or weighing less than 60 kg. Ticagrelor will also be used first-line in high-risk NSTEMI / ACS patients (TIMI score >=4 undergoing PCI). If there are contraindications to ticagrelor, clopidogrel may be considered. Both these agents are for cardiologist initiation only. For STEMI patients not undergoing PCI, NICE recommend aspirin and clopidogrel for at least 4 weeks. Ensure duration of therapy is given in the discharge letter.

An MHRA Drug Safety Update is available on prasugrel, increased risk of bleeding, and advice on timing of loading doses prior to PCI.

8. IV cangrelor (with concomitant aspirin) is available for patients undergoing PCI who have not received treatment with oral clopidogrel, prasugrel or ticagrelor prior to the procedure, and in whom oral therapy with these drugs is not suitable 

Please refer to the RDH / Derbyshire Medicines Management Dual anti-platelet policies:





NSTEMI / Anti-Platelet Therapy


For link to BNF section: 2.9 Antiplatelet drugs