Drug & supplement interaction

Fish Therapy + Diltiazem

Diltiazem brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, and others.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Fish Therapy and Diltiazem 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

Fish Therapy and Diltiazem

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 Diltiazem and Fish Therapy in our sources. This does not guarantee that the combination is completely free of risk — research on Fish Therapy alongside specific medications may be limited.

Worth understanding: our licensed dataset holds no drug-interaction record for Fish Therapy at all — not against Diltiazem, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

Fish Therapy is a treatment rather than something you take. Tell whoever provides it which medicines you use, and ask your prescriber whether it is appropriate for your health and treatment. 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.

Fish Therapy safety at a glance

Fish Therapy overall Use caution Hygiene and infection risks make this a cautious choice, especially with shared water.
Pregnancy Use caution Not studied in pregnancy; avoid due to infection risk unless cleared by your doctor.
Breastfeeding Use caution No safety data; infection risk makes caution reasonable while breastfeeding.

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

Still wondering about combining Diltiazem and Fish Therapy? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Fish Therapy and Diltiazem 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 having Fish Therapy while taking the medicine 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

    Fish Therapy

    “Multiple case reports suggest that fish therapy can increase the risk for bacterial infection. Studies of fish therapy water have identified multiple bacteria capable of causing disease. It is currently not possible to adequately sterilize the water without killing the fish. Additionally, when performed in a spa or salon setting, pedicure tubs cannot be adequately cleaned when fish are present.”

    Fish Therapy · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 103109. Vanhooteghem O, Anseeuw D, Michel C, et al. Fish Pedicure-induced Aeromonas sobria Superficial Necrotic Bullous Dermatitis in a Previously Undiagnosed Diabetes Patient. What are the Risks of Fish Pedicure for Public Health? BJMMR. 2015;10(12):1-10. DOI
    2. 103110. Veraldi S, Nazzaro G, Çuka E. Staphylococcus aureus infection of the feet following fish pedicure. Infection. 2014 Oct;42(5):925-6. PubMed
    3. 103111. Sugimoto K, Frei R, Graber P. Methicillin-resistant Staphylococcus aureus foot infection after fish pedicure. Infection. 2013 Oct;41(5):1013-5. PubMed
    4. 103112. Vanhooteghem O, Theate I. Fish pedicure-induced foot mycobacteriosis infection due to Mycobacterium marinum: a first case report. Eur J Dermatol. 2017 Jun 1;27(3):299-300. PubMed
    5. 103108. Lipner SR. Onychomadesis Following a Fish Pedicure. JAMA Dermatol. 2018 Sep 1;154(9):1091-1092. PubMed
    6. 103113. US Centers for Disease Control (CDC). Fish Pedicures and Fish Spas. August 2, 2016. Available at: https://www.cdc.gov/healthywater/hygiene/body/fish_pedicures.html. Accessed on June 15, 2020.

    Diltiazem

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

  • Swelling / A skin rash Additional detail

    Fish Therapy

    Recorded for Fish Therapy in the same Natural Medicines adverse-effect record shown under A higher chance of infection above.

    Diltiazem

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

Reported for Fish Therapy but not commonly for Diltiazem: liver problems.

Effects for Diltiazem come from the ADVERSE REACTIONS section of its FDA label; effects for Fish Therapy come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 34,400 voluntary FDA FAERS reports for Diltiazem 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.

From our Q&A

Questions About Fish Therapy or Diltiazem

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Fish Therapy or Diltiazem, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Diltiazem

This page covers Fish Therapy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diltiazem page lists 260 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Coleus (major) and Grapefruit (major).

By severity: 7 major · 214 moderate · 39 minor.

From our pharmacist’s overview on the Diltiazem page

“Someone on diltiazem (Cardizem, Tiazac) is usually managing blood pressure, angina, or a fast heart rhythm, so this list deserves genuine care. Seven of the 260 ingredients on file carry a major rating, and two of those are things people actually buy: grapefruit, which blocks the enzyme that clears diltiazem and can push its blood leve…”

Reviewed by 2 · Jul 18, 2026

Open the Diltiazem interaction page

How much people look this up

Where Fish Therapy and Diltiazem 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 Fish Therapy
Steady interest

#1,005 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Diltiazem
Top 10%

#279 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 Fish Therapy reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Fish Therapy and Diltiazem 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 .
Treatment approach

About Fish Therapy

What is Fish Therapy?

  • Psoriasis
  • Skin exfoliation and smoothing
  • Eczema and dry skin
  • Cosmetic foot care (pedicure)
  • General relaxation

Fish therapy (also called ichthyotherapy or a 'fish pedicure') uses small Garra rufa fish to nibble away dead skin, and it is mostly used cosmetically or for skin conditions like psoriasis. Evidence that it treats any medical condition is very limited, and there are real infection and hygiene concerns. If you have a skin condition, talk with a dermatologist before trying it.

Live fish (commonly Garra rufa); the whole animal used in skin-immersion baths · Spa fish baths (foot or full-body immersion with Garra rufa fish)

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

Fish Therapy: dosing

There is no standard 'dose' for fish therapy, since it is a spa procedure rather than a supplement you take. Sessions are usually a set number of minutes in a spa setting.If you choose to try it, only use a reputable, licensed facility that follows strict hygiene rules, and never share water with someone who has a skin infection.

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

Read the full Fish Therapy monograph & all interactions
Medication

About Diltiazem

What Is Diltiazem Used For?

Brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, Diltiaz XT, Diltiaz CD, Dilacor, Diltiaz, Cardizem LA, Dilacor XR, Cartia XT, Tiamate, Adizem-SR, Adizem-XL, Angitil SR, Angitil XL, Calcicard CR, Dilcardia SR, Dilzem SR, Dilzem XL, Slozem, Tildiem LA, Tildiem Retard, Viazem XL, Zemtard 120XL, Zemtard 180XL, Zemtard 240XL, Zemtard 300XL

Oral extended-release forms of diltiazem — including Matzim LA, Cardizem LA, Cartia, Cartia XT, Tiadylt ER, and various generic capsules and tablets — are used to treat high blood pressure (hypertension) and chronic stable angina (chest pain brought on by activity). Some capsule formulations, including Cartia, Cartia XT, and certain generics, are also approved for angina due to coronary artery spasm (sudden chest pain caused by a sudden tightening of a coronary artery).

Injectable forms of diltiazem are used in hospital settings to temporarily slow a dangerously fast heart rate in atrial fibrillation or atrial flutter (rapid, irregular heart rhythms), and to restore a normal heart rhythm in paroxysmal supraventricular tachycardia (PSVT) — sudden episodes of a very fast but regular heartbeat originating above the heart's lower chambers.

Most-Reported Side Effects for Diltiazem

From FAERS, the FDA’s public side-effect reporting system (34,400 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dyspnea 3,309 reports
Fatigue 2,733 reports
Nausea 2,454 reports
Dizziness 2,174 reports
Diarrhea 2,113 reports
See full Diltiazem drug information
Keep checking

Other Drugs & Fish Therapy

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Fish Therapy References

The 8 references that drive our Fish Therapy 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. Grassberger M, Hoch W. Ichthyotherapy as alternative treatment for patients with psoriasis: a pilot study. Evid Based Complement Alternat Med. 2006 Dec;3(4):483-8. PubMed
  2. Lipner SR. Onychomadesis Following a Fish Pedicure. JAMA Dermatol. 2018 Sep 1;154(9):1091-1092. PubMed
  3. Vanhooteghem O, Anseeuw D, Michel C, et al. Fish Pedicure-induced Aeromonas sobria Superficial Necrotic Bullous Dermatitis in a Previously Undiagnosed Diabetes Patient. What are the Risks of Fish Pedicure for Public Health? BJMMR. 2015;10(12):1-10. DOI
  4. Veraldi S, Nazzaro G, Çuka E. Staphylococcus aureus infection of the feet following fish pedicure. Infection. 2014 Oct;42(5):925-6. PubMed
  5. Sugimoto K, Frei R, Graber P. Methicillin-resistant Staphylococcus aureus foot infection after fish pedicure. Infection. 2013 Oct;41(5):1013-5. PubMed
  6. Vanhooteghem O, Theate I. Fish pedicure-induced foot mycobacteriosis infection due to Mycobacterium marinum: a first case report. Eur J Dermatol. 2017 Jun 1;27(3):299-300. PubMed
  7. US Centers for Disease Control (CDC). Fish Pedicures and Fish Spas. August 2, 2016. Available at: https://www.cdc.gov/healthywater/hygiene/body/fish_pedicures.html. Accessed on June 15, 2020.
  8. Vanhooteghem O, Theate I, De Schaetzen V. Periungual Mycobacterium marinum Infection following a Fish Manicure. Skin Appendage Disord. 2021 Aug;7(5):393-396.

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

Having Fish Therapy While Taking Diltiazem: Common Questions

Is it safe to have Fish Therapy while taking Diltiazem?
We do not list a known interaction between Fish Therapy and Diltiazem. 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 Fish Therapy and Diltiazem have any of the same side effects?
Yes — our sources link each of them separately to 3 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.
Does Diltiazem interact with any supplements?
Yes. Diltiazem has documented interactions with 260 supplements in our database — Fish Therapy is not one of them. The Diltiazem interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Diltiazem and Fish Therapy?

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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.