Nitroglycerin Spray and Aspirin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Nitroglycerin Spray
Aspirin
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increase in nitroglycerin concentrations and additive platelet function depression
Interaction Deep Dive
Coadministration of aspirin and nitroglycerin has been reported to result in increased nitroglycerin plasma concentrations, possibly due to decreased clearance14. Additive platelet function depression has also been demonstrated 2.
Why it happens (mechanism)
Decreased nitroglycerin clearance; additive effects
Literature reports
3 reports — tap to read
a) Pretreatment with aspirin 1 gram increased nitroglycerin plasma concentrations and hemodynamic effects 1. Seven healthy male volunteers received two doses of sublingual nitroglycerin 0.4 mg alone, or following 1 gram of oral aspirin. Compared to the control period (nitroglycerin alone), aspirin pretreatment significantly reduced diastolic arterial pressure, end-diastolic diameter, and end-systolic diameter. Heart rate was significantly greater and nitroglycerin plasma levels were increased by 54% (from 0.24 ng/mL to 0.37 ng/mL).
b) The antiaggregatory effects of aspirin and nitroglycerin may possibly be additive. Ten healthy subjects received a single, oral dose of aspirin 500 mg. Twenty-four hours later, intravenous nitroglycerin was begun and was titrated up to a maximum dose of 3 mcg/kg/min or until an intolerable headache developed or the systolic blood pressure decreased to 90 mm Hg or less. Baseline aggregation time averaged 316 seconds and 480 seconds prior to and four hours after the administration of aspirin, respectively. When nitroglycerin was given, aggregation time further increased to an average of 620 seconds. For the entire group, the mean aggregation time increase was 141 seconds. While the administration of aspirin did decrease platelet function, it did not completely abolish it as evidenced by the fact that nitroglycerin further reduced platelet aggregation. This additive depression of platelet function can be explained by the two different pathways which are affected. Aspirin suppresses thromboxane synthesis and nitroglycerin increases the synthesis of cyclic guanosine monophosphate, both resulting in antiaggregatory effects 2.
c) To determine if vasodilatory prostaglandins were responsible for the major hemodynamic changes induced by nitroglycerin, 3 studied 40 healthy subjects given placebo or aspirin 650 mg one hour before sublingual nitroglycerin 432 mcg. The administration of aspirin did not alter the peak hemodynamic response or the area under the time-pressure and time-pulse curves. Because aspirin did not alter the major hemodynamic response, the vasodilatory prostaglandins are probably not a significant contributing factor for the hemodynamic changes induced by nitroglycerin administration.
Common questions
Can I take Nitroglycerin Spray and Aspirin together?
An increase in nitroglycerin concentrations and additive platelet function depression Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nitroglycerin Spray and Aspirin interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Nitroglycerin Spray or Aspirin need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (4)
- Weber S, Rey E, Pipeau C, et al: Influence of aspirin on the hemodynamic effects of sublingual nitroglycerin. J Cardiovasc Pharmacol 1983; 5:874-877. PubMed
- Karlberg KE, Ahlner J, Henriksson P, et al: Effects of nitroglycerin on platelet aggregation beyond the effects of acetylsalicylic acid in healthy subjects. Am J Cardiol 1993; 71:361-364. DOI
- Levin RI & Feit F: The effect of aspirin on the hemodynamic response to nitroglycerin. Am Heart J 1988; 116:77-84. PubMed
- Rey E, El-Assaf HD, Richard MO, et al: Pharmacologic interaction between nitroglycerin and aspirin after acute and chronic aspirin treatment of healthy subject. Eur J Clin Pharmacol 1983; 25:779-782.
Keep reading about Nitroglycerin Spray
Keep reading about Aspirin
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