Causality assessment · Causality: well established

Ticagrelor and Dyspnoea: is the FAERS signal real?

n=4,009 co-reports · PRR 4.7 · ROR 5.3

Ticagrelor side-effect profile All assessments See in the full list

A written Bradford Hill assessment of one drug–event pair. The grade is a judgement about the signal, not a statement that this drug causes this event in any one person; FAERS counts are reports, not rates.

Causality: well established

Ticagrelor ↔ Dyspnoea

n=4,009 co-reports · PRR 4.7 · ROR 5.3

Ticagrelor is a reversible P2Y12 platelet inhibitor whose signature adverse effect is dyspnoea — breathlessness without heart failure or lung disease — thought to reflect adenosine accumulation, because ticagrelor also blocks adenosine re-uptake. This dataset's 4,009 co-reports (PRR 4.7) make dyspnoea one of its largest signals. The effect surfaced in PLATO (NCT00391872), the trial that established ticagrelor over clopidogrel in acute coronary syndromes, and is now a labelled warning; it is usually benign and rarely requires stopping the drug.

Regulatory basis: ticagrelor (Brilinta) prescribing information — dyspnoea; PLATO trial (Wallentin et al., NEJM 2009).

Bradford Hill viewpoint	Status	Note
Temporality (necessary)	met	Occurs within days to weeks of starting
Strength	met	PRR 4.7 with thousands of reports
Consistency	met	Reproduced in PLATO and practice
Specificity	met	Distinctive to ticagrelor among antiplatelets
Biological gradient	partial	Not clearly dose-related at usual doses
Plausibility	met	Adenosine re-uptake inhibition proposed
Coherence	met	Consistent with added adenosine exposure
Experiment	met	Randomised arm comparison showed the excess
Analogy	met	Analogy to adenosine-infusion dyspnoea

This table is this page's own qualitative read of the literature cited above, not an automated or citation-gated assessment — see the note at the bottom of this page.

✓ Trial evidence found — A 30 Day Study to Evaluate Efficacy and Safety of Pre-hospital vs. In-hospital Initiation of Ticagrelor Therapy in STEMI Patients Planned for Percutaneous Coronary Intervention (PCI) (NCT01347580)

Adverse event	Ticagrelor In-Hosp (n=950) · Ticagrelor Pre-Hosp (n=908)
DYSPNOEA	1/950	2/908
Dyspnoea	86/950	62/908

Post-marketing signal terms appear in this trial's posted adverse-event tables; per-arm counts shown as affected/at-risk. View on ClinicalTrials.gov →