Drug & supplement interaction

Inosine + Gefitinib

Gefitinib brand name: Iressa.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Inosine and Gefitinib in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Inosine and Gefitinib

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Gefitinib and Inosine in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Inosine safety at a glance

Inosine overall Use caution Inosine raises uric acid, which may be a problem for people with gout or kidney issues.
Pregnancy Avoid There is not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid use.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Gefitinib and Inosine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Gefitinib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Gefitinib is filed under 3 classifications — hepatotoxic drugs, cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Inosine has documented interactions with 1 drug class — the most serious being antigout drugs (moderate) — and none of Gefitinib’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Inosine Does Interact With Other Medications

Inosine has 9 moderate known drug interactions in our database — Gefitinib isn’t one of them. If you take anything else, check it against the full list below.

Moderate 9 No known interaction 2,821 (incl. Gefitinib)
Taking anything else?

Check Another of Your Medications Against Inosine

Covers the 2,830 medications we’ve checked against Inosine. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Inosine and Gefitinib May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Nausea Additional detail

    Inosine

    “Orally, inosine has been reported to cause nausea.”

    Inosine · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    2 sources cited
    1. 95289. Gonsette RE, Sindic C, D'hooghe MB, et al. Boosting endogenous neuroprotection in multiple sclerosis: The association of inosine and interferon beta in relapsing-remitting Multiple Sclerosis (ASIIMS) trial. Mult Scler. 2010;16(4):455-62.
    2. 106854. Parkinson Study Group SURE-PD3 Investigators, Schwarzschild MA, Ascherio A, et al. Effect of Urate-Elevating Inosine on Early Parkinson Disease Progression: The SURE-PD3 Randomized Clinical Trial. JAMA 2021;326(10):926-939.

    Gefitinib

    Listed in the ADVERSE REACTIONS section of the FDA label for Gefitinib. Read the label on DailyMed ›

Reported for Inosine but not commonly for Gefitinib: kidney stones and raised blood pressure.

Effects for Gefitinib come from the ADVERSE REACTIONS section of its FDA label; effects for Inosine come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 8,974 voluntary FDA FAERS reports for Gefitinib that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Gefitinib Is Prescribed For, and What Inosine Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Gefitinib is a prescription medicine with approved uses on its FDA label. Inosine is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Gefitinib is prescribed for: Gefitinib tablets — sold under the brand name Iressa — are used as a first-line treatment for metastatic non-small cell lung cancer (NSCLC). This treatment is only for patients whose tumors carry specific changes (mutations) in the EGFR gene: either an exon 19 deletion or an exon 21 (L858R) substitution mutation, confirmed by an FDA-approved test. This medicine is not established as safe or effective for NSCLC patients with other types of EGFR mutations. Your doctor will use a genetic test on your tumor or blood to confirm whether gefitinib is right for you.

Inosine has been studied for:

  • Cancer studied, not established Inosine has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Inosine for cancer

    It is unclear if oral inosine is beneficial for cancer.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Gefitinib on your own; if you are taking Inosine for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Gefitinib

This page covers Inosine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Gefitinib page lists 168 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 124 moderate · 38 minor.

Open the Gefitinib interaction page

One more smart check

Taking Inosine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 93 real supplement products containing Inosine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Inosine. Even though Inosine itself has no known interaction with Gefitinib, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Inosine and Gefitinib Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Inosine
Top half

#578 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Gefitinib
Steady interest

#2,825 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Inosine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Inosine and Gefitinib records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Inosine

What is Inosine?

  • Athletic performance and energy
  • Multiple sclerosis (raising uric acid)
  • Parkinson's disease (raising uric acid)
  • General health and recovery

Inosine is a nucleoside (a building block of DNA and RNA) that the body makes on its own and is also sold as a supplement, mostly marketed for athletic performance. Solid evidence that it boosts exercise performance is lacking, and because it raises uric acid levels, it may pose risks for people with gout or kidney problems. Talk with your pharmacist or doctor before using it.

Not applicable; inosine is a naturally occurring compound (a nucleoside), not a plant part · Capsules, tablets, powder

An interaction check asks whether these two react with each other — it does not ask whether Inosine is a good idea for someone in your situation. Here is what our Inosine record says about it on its own.

Inosine: dosing

There is no well-established, standardized dose of inosine. Amounts used in studies have varied, and there is no proven safe or effective dose for general use.If you choose to use an inosine product, follow the directions on the label and do not exceed the recommended amount. Do not assume that taking more will give better results.

From our Inosine monograph — the full record covers uses, side effects and every documented interaction.

Read the full Inosine monograph & all interactions
Medication

About Gefitinib

What Is Gefitinib Used For?

Brand name: Iressa

Gefitinib tablets — sold under the brand name Iressa — are used as a first-line treatment for metastatic non-small cell lung cancer (NSCLC). This treatment is only for patients whose tumors carry specific changes (mutations) in the EGFR gene: either an exon 19 deletion or an exon 21 (L858R) substitution mutation, confirmed by an FDA-approved test.

This medicine is not established as safe or effective for NSCLC patients with other types of EGFR mutations. Your doctor will use a genetic test on your tumor or blood to confirm whether gefitinib is right for you.

Most-Reported Side Effects for Gefitinib

From FAERS, the FDA’s public side-effect reporting system (8,974 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Malignant neoplasm progression 1,821 reports
Drug resistance 1,251 reports
Diarrhea 904 reports
Rash 643 reports
Disease progression 461 reports
See full Gefitinib drug information
Keep checking

Other Drugs & Inosine

Browse every other medication we’ve checked against Inosine — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
9Moderate
0Minor
2,820No known interaction
9 Moderate 2,820 No interaction
Moderate

9 interactions

No interaction 2,820 drugs checked — show the list

We also checked Inosine against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,820 medications checked with no known interaction — see the full Inosine list.

See the full Inosine interactions page
See every supplement checked against Gefitinib, ranked by severity
Evidence & sources

Inosine References

The 7 references that drive our Inosine monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Parkinson Study Group SURE-PD Investigators. Inosine to increase serum and cerebrospinal fluid urate in Parkinson disease: a randomized clinical trial. JAMA Neurol. 2014;71(2):141-50.
  2. Muñoz García D, Midaglia L, Martinez Vilela J, et al. Associated inosine to interferon: results of a clinical trial in multiple sclerosis. Acta Neurol Scand. 2015;131(6):405-10. PubMed
  3. Gonsette RE, Sindic C, D'hooghe MB, et al. Boosting endogenous neuroprotection in multiple sclerosis: The association of inosine and interferon beta in relapsing-remitting Multiple Sclerosis (ASIIMS) trial. Mult Scler. 2010;16(4):455-62.
  4. Markowitz CE, Spitsin S, Zimmerman V, et al. The treatment of multiple sclerosis with inosine. J Altern Complement Med. 2009;15(6):619-25. PubMed
  5. Watanabe H, Hattori T, Kume A, et al. Improved Parkinsons disease motor score in a single-arm open-label trial of febuxostat and inosine. Medicine (Baltimore) 2020;99(35):e21576. PubMed
  6. Parkinson Study Group SURE-PD3 Investigators, Schwarzschild MA, Ascherio A, et al. Effect of Urate-Elevating Inosine on Early Parkinson Disease Progression: The SURE-PD3 Randomized Clinical Trial. JAMA 2021;326(10):926-939.
  7. Walk D, Nicholson K, Locatelli E, et al. Randomized trial of inosine for urate elevation in amyotrophic lateral sclerosis. Muscle Nerve 2023;67(5):378-386. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Inosine and Gefitinib Together: Common Questions

Is it safe to take Inosine with Gefitinib?
We do not list a known interaction between Inosine and Gefitinib. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Inosine and Gefitinib have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Inosine and Gefitinib used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Inosine in each. That is a conversation for your prescriber, especially if Gefitinib is being adjusted to a target.
How was the Inosine and Gefitinib combination checked?
Interactions in our licensed database are recorded against drug classes. Gefitinib is filed under 3 classifications, and Inosine has documented interactions with 1 drug class — none of Gefitinib's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Inosine interact with any other medications?
Yes. Inosine has 9 documented drug interactions in our database — Gefitinib is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Gefitinib interact with any supplements?
Yes. Gefitinib has documented interactions with 168 supplements in our database — Inosine is not one of them. The Gefitinib interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Inosine monograph Uses, safety profile, and every drug interaction in one place Gefitinib drug information The full plain-English guide to this medication Gefitinib supplement interactions Every supplement checked against Gefitinib, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Gefitinib and Inosine?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.