Drug Interaction Report

Acetaminophen Rectal and Ethinyl Estradiol: Interaction Details

Name: Acetaminophen Rectal and Ethinyl Estradiol Interaction
Creator: Dr. Brian Staiger, PharmD, BCPS

A pharmacist-reviewed analysis of the Acetaminophen Rectal and Ethinyl Estradiol interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Ethinyl Estradiol

No brand names on record

Acetaminophen Rectal

Acephen Acephen Rectal Suppository® Feverall Feverall Rectal Suppository® Neopap Supprettes Rectal Suppository® Tylenol Rectal Suppository®

Medically reviewed by

Dr. Brian Staiger, PharmD, BCPS

Updated Jul 10, 2026

Editorial policy · Data sources

Interaction severity

Moderate

Can be significant — usually manageable with monitoring.

Minor

Moderate

Major

Contraindicated

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.

Of 28 documented Acetaminophen Rectal interactions, 13 are rated moderate — including this one.

Onset

unspecified

Evidence

theoretical

Severity

Moderate

What happens

Increased ethinyl estradiol exposure and reduced acetaminophen exposure

Interaction Deep Dive

Concomitant use of acetaminophen and an oral combination contraceptive that contains ethinyl estradiol and norethindrone may cause elevated plasma concentrations of ethinyl estradiol possibly by inhibition of conjugation. Also, COCs have been shown to decrease plasma concentrations of acetaminophen¹.

Why it happens (mechanism)

Inhibition of conjugation; unknown

Common questions

Can I take Acetaminophen Rectal and Ethinyl Estradiol together?

Increased ethinyl estradiol exposure and reduced acetaminophen exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Acetaminophen Rectal and Ethinyl Estradiol interaction?

It is rated moderate. Can be significant — usually manageable with monitoring.

How quickly could this interaction happen?

The documented onset is "unspecified". The timing of this interaction is not well characterized.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

Does my dose of Acetaminophen Rectal or Ethinyl Estradiol 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 (1)

Product Information: LOESTRIN(R) 24 Fe oral tablets, norethindrone acetate ethinyl estradiol oral tablets, ferrous fumarate oral tablets. Teva Pharmaceuticals USA Inc (per FDA), Parsippany, NJ, 2023. DailyMed

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Ethinyl Estradiol

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All Ethinyl Estradiol interactions (102)

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Acetaminophen Rectal

Keep reading about Acetaminophen Rectal

All Acetaminophen Rectal interactions (28) Acetaminophen Rectal drug information

Also serious with: Articaine Carbamazepine Exenatide Flucloxacillin

Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Ethinyl Estradiol + Activated Charcoal Grapefruit St. John's Wort Acacia Rigidula Adrafinil African Wild Potato Aletris Alfalfa + 203 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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A message from HelloPharmacist

About our interaction database: depth, not breadth

HelloPharmacist doesn't license one of the big commercial interaction databases, so what you'll find here is not a complete list of every known drug interaction. Instead, each entry is researched, analyzed, and written up individually — documented from the published literature, reviewed by a pharmacist, and cited so you can check every source yourself.

If a combination isn't listed here, it means we haven't documented it yet — never that it's safe. For screening a full medication list, we recommend pairing this site with a comprehensive tool like the Drugs.com Interaction Checker and, most importantly, a review by your own pharmacist. For a deep, plain-English, fully sourced explanation of a specific documented interaction — that's exactly what we built this for.

This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.