Drug & supplement interaction

Lactobacillus Acidophilus + Erlotinib

Erlotinib brand name: Tarceva.

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 Lactobacillus Acidophilus and Erlotinib 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 label for Erlotinib states a food rule worth keeping to, and 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

Lactobacillus Acidophilus and Erlotinib

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 Erlotinib and Lactobacillus Acidophilus 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.

Lactobacillus Acidophilus safety at a glance

Lactobacillus Acid... overall Generally safe Generally well tolerated in healthy adults and children.
Pregnancy Possibly Safe When used orally and appropriately. A combination of Lactobacillus acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum has been used with apparen... Read the full pregnancy detail
Breastfeeding Use caution Likely low risk, but data are limited so ask your healthcare provider.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Erlotinib and Lactobacillus Acidophilus? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Erlotinib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Erlotinib is filed under 2 classifications — including oral drugs. Lactobacillus Acidophilus has documented interactions with 1 drug class — the most serious being antibiotic drugs (moderate) — and none of Erlotinib’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

Lactobacillus Acidophilus Does Interact With Other Medications

Lactobacillus Acidophilus has 182 moderate known drug interactions in our database — Erlotinib isn’t one of them. If you take anything else, check it against the full list below.

Moderate 182 No known interaction 2,648 (incl. Erlotinib)
Taking anything else?

Check Another of Your Medications Against Lactobacillus Acidophilus

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

What to actually watch for

No Interaction Found — But Data Suggests Lactobacillus Acidophilus and Erlotinib May Share Several of the Same Side Effects

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. One of them is worth acting on rather than waiting out — marked below.

  • A higher chance of infection Worth acting on Additional detail

    Lactobacillus Acidophilus

    “Since Lactobacillus acidophilus preparations contain live and active microorganisms, there is some concern that they might cause pathogenic infection in some patients. L. acidophilus has been isolated in some cases of bacteremia, sepsis, splenic abscess, liver abscess, endocarditis, necrotizing fasciitis, pancreatic necrosis, and meningoencephalitis.”

    Lactobacillus Acidophilus · Natural Medicines adverse-effect record, reported in age-related macular degeneration (amd).

    5 sources cited
    1. 107543. Rossi F, Amadoro C, Gasperi M, Colavita G. Lactobacilli infection case reports in the last three years and safety implications. Nutrients. 2022;14(6):1178. PubMed
    2. 111782. Ozer M, Goksu SY, Shahverdiani A, Mustafa M. Lactobacillus acidophilus-induced endocarditis and associated splenic abscess. Case Rep Infect Dis 2020;2020:1382709.
    3. 111792. Cukovic-Cavka S, Likic R, Francetic I, Rustemovic N, Opacic M, Vucelic B. Lactobacillus acidophilus as a cause of liver abscess in a NOD2/CARD15-positive patient with Crohn's disease. Digestion 2006;73(2-3):107-10.
    4. 111787. Stoffer JN, Slingsby TJ, Giuliari GP. Lactobacillus acidophilus endophthalmitis after intravitreal bevacizumab injection requiring intraocular lens explantation. Can J Ophthalmol 2022;57(1):e21-e22. PubMed
    5. 111795. Hui J, Ren Y, Wang Y, Han Q. Lactobacillus acidophilus endophthalmitis postcataract operation: A case report with a literature review. Ocul Immunol Inflamm 2023.

    Erlotinib

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

  • Stomach upset / Diarrhea / Vomiting reported in 10.8% of FDA reports for Erlotinib Additional detail

    Lactobacillus Acidophilus

    “Orally, taking Lactobacillus acidophilus in combination with other probiotics may cause gastrointestinal side effects including epigastric discomfort, abdominal pain, dyspepsia, flatulence, bloating, diarrhea, vomiting, and burping; however, these events are uncommon.”

    Lactobacillus Acidophilus · Natural Medicines adverse-effect record, reported in diarrhea.

    6 sources cited
    1. 90239. Chatterjee S, Kar P, Das T, Ray S, Gangulyt S, Rajendiran C, Mitra M. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated
    2. 90291. Shavakhi A, Tabesh E, Yaghoutkar A, Hashemi H, Tabesh F, Khodadoostan M,Minakari M, Shavakhi S, Gholamrezaei A. The effects of multistrain probiotic compound on bismuth-containing quadruple therapy for Helicobacter pylori infection: a randomized placebo-c
    3. 111785. Sadrin S, Sennoune S, Gout B, et al. A 2-strain mixture of Lactobacillus acidophilus in the treatment of irritable bowel syndrome: A placebo-controlled randomized clinical trial. Dig Liver Dis 2020;52(5):534-540. PubMed
    4. 107497. Kumar S, Kumar R, Rohilla L, Jacob N, Yadav J, Sachdeva N. A high potency multi-strain probiotic improves glycemic control in children with new-onset type 1 diabetes mellitus: A randomized, double-blind, and placebo-controlled pilot study. Pediatr Diabete
    5. 107520. Shahriari A, Karimi E, Shahriari M, Aslani N, Khooshideh M, Arab A. The effect of probiotic supplementation on the risk of gestational diabetes mellitus among high-risk pregnant women: A parallel double-blind, randomized, placebo-controlled clinical trial PubMed
    6. 107537. Xiao SD, Zhang DZ, Lu H, et al. Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea. Adv Ther. 2003;20(5):253-60.

    Erlotinib

    Listed in the ADVERSE REACTIONS section of the FDA label for Erlotinib, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • A skin rash / Itching reported in 10.6% of FDA reports for Erlotinib Additional detail

    Lactobacillus Acidophilus

    “Orally, in one clinical trial, a combination of Lactobacillus acidophilus La-5, Lacticaseibacillus paracasei subsp. paracasei F19, and Bifidobacterium animalis subsp. lacltis BB-12 was associated with two cases of rash, one with itching. However, it is not clear if these adverse effects were due to L. acidophilus, other ingredients, the combination, or if the events were idiosyncratic.”

    Lactobacillus Acidophilus · Natural Medicines adverse-effect record, reported in pruritus.

    1 source cited
    1. 90236. Begtrup LM, de Muckadell OB, Kjeldsen J, Christensen RD, Jarbøl DE. Long-term treatment with probiotics in primary care patients with irritable bowel syndrome--a randomised, double-blind, placebo controlled trial. Scand J Gastroenterol 2013;48(10):1127-35 PubMed

    Erlotinib

    Listed in the ADVERSE REACTIONS section of the FDA label for Erlotinib, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Lactobacillus Acidophilus but not commonly for Erlotinib: stomach pain and bloating or gas.

Effects for Erlotinib come from the ADVERSE REACTIONS section of its FDA label; effects for Lactobacillus Acidophilus come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 12,442 voluntary FDA FAERS reports for Erlotinib 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.

Special populations

Lactobacillus Acidophilus in Pregnancy & Breastfeeding

Pregnancy Possibly Safe

When used orally and appropriately. A combination of Lactobacillus acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum has been used with apparent safety for 6 weeks, starting at 24-28 weeks' gestation.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Erlotinib Products Have a Food Rule — Lactobacillus Acidophilus Should Not Break It

At least one FDA label for a product containing Erlotinib says to take it on an empty stomach. Most supplements — Lactobacillus Acidophilus included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Erlotinib on its own and move Lactobacillus Acidophilus to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Erlotinib products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Recommended Dose – NSCLC The recommended daily dose of erlotinib tablets for NSCLC is 150 mg taken on an empty stomach, i.e., at least one hour before or two hours after the ingestion of food.

From the Dosage and Administration section of the FDA label we read for Erlotinib — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Erlotinib

This page covers Lactobacillus Acidophilus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Erlotinib page lists 18 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Bilberry (moderate), Coffee Charcoal (moderate), European Mandrake (moderate) and Glucomannan (moderate).

By severity: 1 major · 8 moderate · 9 minor.

From our pharmacist’s overview on the Erlotinib page

“Activated charcoal is the entry I would flag first for anyone taking erlotinib (Tarceva), an oral targeted therapy for certain lung cancers. Charcoal can adsorb the drug in the gut and cut how much reaches the bloodstream, and with a cancer pill, less absorbed means less cancer fought.”

Reviewed by 2 · Jul 18, 2026

Open the Erlotinib interaction page

One more smart check

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

We hold 6,180 real supplement products containing Lactobacillus Acidophilus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lactobacillus Acidophilus. Even though Lactobacillus Acidophilus itself has no known interaction with Erlotinib, 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 Lactobacillus Acidophilus and Erlotinib 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 Lactobacillus Acidophilus
Top 5%

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

29 days ago today
Medication Erlotinib
Top half

#1,373 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 Lactobacillus Acidophilus reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Lactobacillus Acidophilus and Erlotinib records this page draws on were last updated July 11, 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 Lactobacillus Acidophilus

What is Lactobacillus Acidophilus?

Lactobacillus Acidophilus
  • Digestive health and balance
  • Diarrhea (including antibiotic-related)
  • Vaginal yeast and bacterial infections
  • Lactose intolerance
  • General immune support

Lactobacillus acidophilus is a 'friendly' bacterium used as a probiotic to support gut and vaginal health. It is generally well tolerated in healthy people, and there is reasonable evidence it may help with certain types of diarrhea, but proof for many other uses is limited. People with weakened immune systems or serious illness should check with a doctor before using it.

Lactobacillus acidophilus · Lactobacillaceae · Live bacterial cultures (the whole microorganism) · Capsules, tablets, chewables, powders, fermented foods (yogurt, kefir), and vaginal suppositories

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

Lactobacillus Acidophilus: dosing

There is no single official dose for L. acidophilus. Probiotic doses are usually measured in 'colony-forming units' (CFUs), and products vary widely in strength and strain.The best approach is to follow the directions on the product label, since these are based on the specific strain in that product. A pharmacist can help you choose a reputable product and a reasonable amount.Probiotics are often taken with or near a meal.

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

Read the full Lactobacillus Acidophilus monograph & all interactions
Medication

About Erlotinib

What Is Erlotinib Used For?

Brand name: Tarceva

Erlotinib tablets are used to treat metastatic non-small cell lung cancer (NSCLC) in patients whose tumors carry specific gene changes — EGFR exon 19 deletions or exon 21 (L858R) mutations — confirmed by an FDA-approved test. It can be used as a first-line treatment, as maintenance therapy, or after at least one prior chemotherapy has stopped working.

Erlotinib tablets are also used for the first-line treatment of locally advanced, unresectable, or metastatic pancreatic cancer — but only in combination with another chemotherapy drug called gemcitabine. Erlotinib is not recommended alongside platinum-based chemotherapy regimens.

Most-Reported Side Effects for Erlotinib

From FAERS, the FDA’s public side-effect reporting system (12,442 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 1,341 reports
Rash 1,316 reports
Malignant neoplasm progression 891 reports
Fatigue 719 reports
Nausea 696 reports
See full Erlotinib drug information
Keep checking

Other Drugs & Lactobacillus Acidophilus

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

0Major
182Moderate
0Minor
2,647No known interaction
182 Moderate 2,647 No interaction
Moderate

182 interactions

Showing 60 of 182 moderate interactions — see all 182 on the Lactobacillus Acidophilus page.

No interaction 2,647 drugs checked — show the list

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

Showing the 60 most looked-up of 2,647 medications checked with no known interaction — see the full Lactobacillus Acidophilus list.

See the full Lactobacillus Acidophilus interactions page
See every supplement checked against Erlotinib, ranked by severity
Evidence & sources

Lactobacillus Acidophilus References

The 15 references that drive our Lactobacillus Acidophilus 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. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. Begtrup LM, de Muckadell OB, Kjeldsen J, Christensen RD, Jarbøl DE. Long-term treatment with probiotics in primary care patients with irritable bowel syndrome--a randomised, double-blind, placebo controlled trial. Scand J Gastroenterol 2013;48(10):1127-35 PubMed
  3. Chatterjee S, Kar P, Das T, Ray S, Gangulyt S, Rajendiran C, Mitra M. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated
  4. Shavakhi A, Tabesh E, Yaghoutkar A, Hashemi H, Tabesh F, Khodadoostan M,Minakari M, Shavakhi S, Gholamrezaei A. The effects of multistrain probiotic compound on bismuth-containing quadruple therapy for Helicobacter pylori infection: a randomized placebo-c
  5. Karamali M, Dadkhah F, Sadrkhanlou M, et al. Effects of probiotic supplementation on glycaemic control and lipid profiles in gestational diabetes: a randomized, double-blind, placebo-controlled trial. Diabetes Metab 2016;42(4):234-41. PubMed
  6. Badehnoosh B, Karamali M, Zarrati M, et al. The effects of probiotic supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes. J Matern Fetal Neonatal Med. 2018 May;31(9):1128-1136.
  7. Kumar S, Kumar R, Rohilla L, Jacob N, Yadav J, Sachdeva N. A high potency multi-strain probiotic improves glycemic control in children with new-onset type 1 diabetes mellitus: A randomized, double-blind, and placebo-controlled pilot study. Pediatr Diabete
  8. Shahriari A, Karimi E, Shahriari M, Aslani N, Khooshideh M, Arab A. The effect of probiotic supplementation on the risk of gestational diabetes mellitus among high-risk pregnant women: A parallel double-blind, randomized, placebo-controlled clinical trial PubMed
  9. Xiao SD, Zhang DZ, Lu H, et al. Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea. Adv Ther. 2003;20(5):253-60.
  10. Rossi F, Amadoro C, Gasperi M, Colavita G. Lactobacilli infection case reports in the last three years and safety implications. Nutrients. 2022;14(6):1178. PubMed
  11. Ozer M, Goksu SY, Shahverdiani A, Mustafa M. Lactobacillus acidophilus-induced endocarditis and associated splenic abscess. Case Rep Infect Dis 2020;2020:1382709.
  12. Sadrin S, Sennoune S, Gout B, et al. A 2-strain mixture of Lactobacillus acidophilus in the treatment of irritable bowel syndrome: A placebo-controlled randomized clinical trial. Dig Liver Dis 2020;52(5):534-540. PubMed
  13. Stoffer JN, Slingsby TJ, Giuliari GP. Lactobacillus acidophilus endophthalmitis after intravitreal bevacizumab injection requiring intraocular lens explantation. Can J Ophthalmol 2022;57(1):e21-e22. PubMed
  14. Cukovic-Cavka S, Likic R, Francetic I, Rustemovic N, Opacic M, Vucelic B. Lactobacillus acidophilus as a cause of liver abscess in a NOD2/CARD15-positive patient with Crohn's disease. Digestion 2006;73(2-3):107-10.
  15. Hui J, Ren Y, Wang Y, Han Q. Lactobacillus acidophilus endophthalmitis postcataract operation: A case report with a literature review. Ocul Immunol Inflamm 2023.

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 Lactobacillus Acidophilus and Erlotinib Together: Common Questions

Is it safe to take Lactobacillus Acidophilus with Erlotinib?
We do not list a known interaction between Lactobacillus Acidophilus and Erlotinib. 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 Lactobacillus Acidophilus and Erlotinib have any of the same side effects?
Yes — our sources link each of them separately to 6 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.
Should I take Lactobacillus Acidophilus and Erlotinib at the same time of day?
At least one FDA label for a product containing Erlotinib says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Erlotinib on its own and move Lactobacillus Acidophilus to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Lactobacillus Acidophilus and Erlotinib combination checked?
Interactions in our licensed database are recorded against drug classes. Erlotinib is filed under 2 classifications, and Lactobacillus Acidophilus has documented interactions with 1 drug class — none of Erlotinib'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 Lactobacillus Acidophilus interact with any other medications?
Yes. Lactobacillus Acidophilus has 182 documented drug interactions in our database — Erlotinib 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 Erlotinib interact with any supplements?
Yes. Erlotinib has documented interactions with 18 supplements in our database — Lactobacillus Acidophilus is not one of them. The Erlotinib 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

Lactobacillus Acidophilus monograph Uses, safety profile, and every drug interaction in one place Erlotinib drug information The full plain-English guide to this medication Erlotinib supplement interactions Every supplement checked against Erlotinib, 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 15 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Erlotinib and Lactobacillus Acidophilus?

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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.