Know What Interacts with Aminocaproic Acid Before You Take It

When you're prescribed a new medication, one of the most important safety steps is checking for drug interactions. Aminocaproic Acid (brand name Amicar) can interact with several other medications in ways that increase your risk of dangerous side effects — particularly blood clots.

This guide covers the major and moderate drug interactions, supplements and over-the-counter products to watch, food interactions, and what you need to tell your doctor before starting Aminocaproic Acid.

How Drug Interactions Work

Drug interactions happen when one medication changes how another medication works. With Aminocaproic Acid, the most important interactions involve medications that also affect blood clotting. Since Aminocaproic Acid prevents clot breakdown, combining it with drugs that promote clotting can push the balance too far — leading to excessive clotting (thrombosis), which can cause deep vein thrombosis (DVT), pulmonary embolism (PE), heart attack, or stroke.

Interactions can also go the other direction: combining Aminocaproic Acid with clot-dissolving drugs (thrombolytics) can cancel out the effects of one or both medications, making treatment less effective.

Major Drug Interactions

These interactions carry the highest risk and generally require avoiding the combination or very close medical monitoring:

Factor IX Complex Concentrates and Anti-Inhibitor Coagulant Concentrates

These blood products are used to treat certain clotting factor deficiencies (such as Hemophilia B). When combined with Aminocaproic Acid, the risk of thrombosis is significantly increased. Examples include:

• Factor IX complex (Bebulin, Profilnine)
• Anti-inhibitor coagulant complex (FEIBA)

If you need both treatments, your doctor will carefully weigh the risks and monitor you closely.

Estrogens and Hormonal Contraceptives

Estrogen-containing medications increase your body's tendency to form clots. Combining them with Aminocaproic Acid — which prevents clot breakdown — creates a double risk for thrombosis. Watch out for:

• Combined oral contraceptives (birth control pills containing estrogen, such as Yaz, Lo Loestrin, Ortho Tri-Cyclen)
• Estrogen patches and rings (NuvaRing, Xulane)
• Hormone replacement therapy (Premarin, Estrace)

If you're taking hormonal contraceptives, tell your doctor before starting Aminocaproic Acid. You may need to switch to a non-estrogen birth control method.

Tretinoin (All-Trans Retinoic Acid)

Tretinoin, used to treat acute promyelocytic leukemia (brand name Vesanoid), increases the risk of thrombotic complications when combined with Aminocaproic Acid. If you're being treated for this type of leukemia, your oncologist will need to carefully manage the combination.

Defibrotide (Defitelio)

Defibrotide is used to treat hepatic veno-occlusive disease. Aminocaproic Acid decreases the effects of Defibrotide through pharmacodynamic antagonism — essentially, the two drugs work against each other. This combination should be avoided.

Moderate Drug Interactions

Thrombolytic Agents (Clot-Dissolving Drugs)

Since Aminocaproic Acid prevents clot breakdown and thrombolytics promote clot breakdown, these drugs directly oppose each other. Examples include:

• Alteplase (Activase) — used for stroke and heart attack
• Reteplase (Retavase)
• Tenecteplase (TNKase)

If you've recently received a thrombolytic drug, your doctor needs to know before administering Aminocaproic Acid, and vice versa.

Other Hemostatic Agents

Combining Aminocaproic Acid with other medications that promote clotting can create additive effects, increasing the risk of excessive clotting. This includes other antifibrinolytics like Tranexamic Acid (Lysteda, Cyklokapron).

Supplements and Over-the-Counter Products to Watch

While Aminocaproic Acid doesn't have as many supplement interactions as some medications, there are still some things to be cautious about:

• Vitamin K supplements — Vitamin K promotes blood clotting. Taking high-dose Vitamin K supplements while on Aminocaproic Acid could further increase clotting risk.
• Iron supplements — While not a direct interaction, patients taking Aminocaproic Acid for bleeding often have low iron. Your doctor may recommend iron supplementation, but coordinate this with them.
• Fish oil / Omega-3 fatty acids — These can have mild blood-thinning effects. While this doesn't directly interact with Aminocaproic Acid, it's worth mentioning to your doctor for a complete picture.
• NSAIDs (Ibuprofen, Naproxen, Aspirin) — These over-the-counter pain relievers affect platelet function and can increase bleeding risk. If you're taking Aminocaproic Acid to control bleeding, adding NSAIDs could complicate the situation. Ask your doctor before taking any NSAID.

Food and Drink Interactions

The good news: Aminocaproic Acid has no significant food interactions. You can take it with or without food. Taking it with a meal or snack may help reduce nausea, which is one of the most common side effects.

There are no known interactions with alcohol, but since both alcohol and Aminocaproic Acid can cause dizziness and nausea, combining them may worsen these side effects. Use caution and follow your doctor's advice about alcohol consumption during treatment.

What to Tell Your Doctor

Before starting Aminocaproic Acid, make sure your doctor has a complete picture of everything you're taking. Specifically, tell them about:

• All prescription medications — especially blood thinners, hormonal medications, cancer treatments, and clotting factor products
• Over-the-counter medications — including NSAIDs (Ibuprofen, Aspirin, Naproxen), antacids, and cold/flu medications
• Vitamins and supplements — including Vitamin K, fish oil, and herbal products
• Your medical history — especially any history of blood clots (DVT, PE, stroke), kidney disease, heart disease, or current pregnancy
• Planned surgeries or procedures — your surgical team needs to know you're on an antifibrinolytic

Don't assume your doctor knows about something just because it's in your chart. Always mention it, especially at a new specialist's office.

Final Thoughts

Aminocaproic Acid is generally safe when used as directed, but its interactions with clotting-related medications are serious and need to be carefully managed. The biggest risks come from combining it with Factor IX products, estrogen-containing medications, and thrombolytics.

The best thing you can do is keep an updated medication list and share it with every healthcare provider you see. If you have questions about whether a specific medication or supplement is safe to take with Aminocaproic Acid, ask your doctor or pharmacist — they can check for interactions quickly.

For more information about this medication, explore our guides on what Aminocaproic Acid is, side effects to watch for, and how to save money on your prescription. If you need help finding a pharmacy that has it in stock, try Medfinder.