Drug & supplement interaction

Choline + Methazolamide

Methazolamide brand name: Neptazane.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Choline and Methazolamide 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

Choline and Methazolamide

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 Methazolamide and Choline 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.

Choline safety at a glance

Choline overall Use caution Generally safe in food amounts, but high-dose supplements can cause side effects and have a daily upper limit.
Pregnancy Likely Safe When used orally and appropriately. Choline is safe when taken in doses below the tolerable upper intake level (UL), which is 3 grams daily during pregnancy and... Read the full pregnancy detail
Breastfeeding Likely Safe When used orally and appropriately. Choline is safe when taken in doses below the tolerable upper intake level (UL), which is 3 grams daily during pregnancy and... Read the full breastfeeding detail

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 Methazolamide and Choline? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Methazolamide

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methazolamide is filed under 5 classifications — including carbonic anhydrase inhibitors, diuretic drugs, antihypertensive drugs. Choline has documented interactions with 1 drug class — the most serious being atropine (minor) — and none of Methazolamide’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

Choline Does Interact With Other Medications

Choline has 16 minor known drug interactions in our database — Methazolamide isn’t one of them. If you take anything else, check it against the full list below.

Minor 16 No known interaction 2,814 (incl. Methazolamide)
Taking anything else?

Check Another of Your Medications Against Choline

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

What to actually watch for

No Interaction Found — But Data Suggests Choline and Methazolamide 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.

  • Reduced appetite / Stomach upset Additional detail

    Choline

    “Orally, large doses of choline can cause nausea, vomiting, salivation, and anorexia. Gastrointestinal discomfort has reportedly occurred with doses of 9 grams daily, while gastroenteritis has reportedly occurred with doses of 32 grams daily. Doses of lecithin 100 grams standardized to 3.5% choline have reportedly caused diarrhea and fecal incontinence.”

    Choline · Natural Medicines adverse-effect record, reported in anorexia.

    5 sources cited
    1. 42275. Wood, J. L. and Allison, R. G. Effects of consumption of choline and lecithin on neurological and cardiovascular systems. Fed.Proc. 1982;41(14):3015-3021.
    2. 91231. Sidhu N, Davies S, Nadarajah A, et al. Oral choline supplementation for postoperative pain. Br J Anaesth 2013;111(2):249-55. PubMed
    3. 42291. Smith, C. M., Swash, M., Exton-Smith, A. N., Phillips, M. J., Overstall, P. W., Piper, M. E., and Bailey, M. R. Choline therapy in Alzheimer's disease. Lancet 8-5-1978;2(8084):318. PubMed
    4. 42310. Morrison, L. M. and W. F. Gonzales. Choline in coronary atherosclerosis. Amer.Heart J. 1950;39:729.
    5. 42312. Christie, J. G. Blackburn 1. M. Glen A. I. M. Zeisel S. Shering A. & Yates C. M. Effects of choline and lecithin on CSF choline levels and on cognitive functioning in patients with presenile dementia of the Alzheimer type. Nutrition and the brain 1979;5

    Methazolamide

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

  • Diarrhea / Vomiting / Nausea Additional detail

    Choline

    “Orally, choline is well tolerated when used appropriately. Adverse effects have been reported with doses exceeding the tolerable upper intake level (UL) of 3.5 grams daily.

    Most Common Adverse Effects:

    Orally: Fishy body odor. At high doses of at least 9 grams daily, choline has been reported to cause diarrhea, nausea, salivation, sweating, and vomiting.”

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

    Methazolamide

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

Reported for Choline but not commonly for Methazolamide: loss of bladder control, low blood pressure, low mood and sweating.

Effects for Methazolamide come from the ADVERSE REACTIONS section of its FDA label; effects for Choline come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 339 voluntary FDA FAERS reports for Methazolamide 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

Choline in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally and appropriately. Choline is safe when taken in doses below the tolerable upper intake level (UL), which is 3 grams daily during pregnancy and lactation in those up to 18 years of age and 3.5 grams daily for those 19 years and older. There is insufficient reliable information available about the safety of choline used in higher doses during pregnancy and lactation.

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

From our Q&A

Questions About Choline or Methazolamide

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Choline or Methazolamide, 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 Methazolamide

This page covers Choline only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methazolamide page lists 218 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), Lithium (major) and Oleander (major).

By severity: 7 major · 187 moderate · 24 minor.

From our pharmacist’s overview on the Methazolamide page

“Methazolamide (Neptazane) treats glaucoma by lowering pressure inside the eye, and because it also has mild water-pill effects it can nudge blood pressure and potassium on its own. That is exactly where most of the 218 supplements on this page press, and the list earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Methazolamide interaction page

One more smart check

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

We hold 11,172 real supplement products containing Choline, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Choline. Even though Choline itself has no known interaction with Methazolamide, 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 Choline and Methazolamide 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 Choline
Top 5%

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

29 days ago today
Medication Methazolamide
Steady interest

#2,438 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 Choline reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Choline and Methazolamide 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 Choline

What is Choline?

Choline
  • Liver health and fatty liver
  • Brain and memory support
  • Prenatal nutrition and fetal development
  • General nutritional supplementation
  • Sports performance

Choline is an essential nutrient your body needs for liver function, brain health, and nerve signaling, and many people get enough from foods like eggs, meat, and fish. Supplements may help people who are deficient or who have higher needs (such as during pregnancy), but they are not proven cure-alls and very high doses can cause side effects. Check with your pharmacist or doctor before starting a supplement.

Not applicable (an essential nutrient found in foods and made in the body) · Capsules, tablets, softgels, and powders; common forms include choline bitartrate, choline chloride, phosphatidylcholine, alpha-GPC, and CDP-choline (citicoline)

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

Choline: dosing

There is no single "treatment" dose of choline that works for everyone, and the right amount depends on your age, sex, life stage, and diet. Health authorities have set recommended adequate intake levels for daily choline as well as a daily upper limit, but these are general nutrition guides rather than doses for treating any condition.Supplements come in different strengths and forms, and the amount of actual choline varies by form.

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

Read the full Choline monograph & all interactions
Medication

About Methazolamide

What Is Methazolamide Used For?

Brand name: Neptazane

Methazolamide tablets are used to treat eye conditions where lowering intraocular pressure (pressure inside the eye) is expected to help. These include chronic open-angle glaucoma and secondary glaucoma.

Methazolamide tablets are also used before surgery in acute angle-closure glaucoma, when reducing eye pressure ahead of the procedure is needed. Note that long-term use in angle-closure glaucoma is not appropriate.

Most-Reported Side Effects for Methazolamide

From FAERS, the FDA’s public side-effect reporting system (339 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 41 reports
Dizziness 29 reports
Dyspnea 28 reports
Headache 28 reports
Blood pressure increased 22 reports
See full Methazolamide drug information
Keep checking

Other Drugs & Choline

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

0Major
0Moderate
16Minor
2,813No known interaction
16 Minor 2,813 No interaction
Minor

16 interactions

No interaction 2,813 drugs checked — show the list

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

Showing the 60 most looked-up of 2,813 medications checked with no known interaction — see the full Choline list.

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

Choline References

The 14 references that drive our Choline 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. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  2. Cho E, Willett WC, Colditz GA, et al. Dietary choline and betaine and the risk of distal colorectal adenoma in women. J Natl Cancer Inst 2007;99:1224-31. PubMed
  3. Schmidt, C., Abicht, A., Krampfl, K., Voss, W., Stucka, R., Mildner, G., Petrova, S., Schara, U., Mortier, W., Bufler, J., Huebner, A., and Lochmuller, H. Congenital myasthenic syndrome due to a novel missense mutation in the gene encoding choline acetyl
  4. Tamminga, C., Smith, R. C., Chang, S., Haraszti, J. S., and Davis, J. M. Depression associated with oral choline. Lancet 10-23-1976;2(7991):905. PubMed
  5. Wood, J. L. and Allison, R. G. Effects of consumption of choline and lecithin on neurological and cardiovascular systems. Fed.Proc. 1982;41(14):3015-3021.
  6. Growdon, J. H. and Gelenberg, A. J. Choline and lecithin administration to patients with tardive dyskinesia. Trans.Am.Neurol.Assoc. 1978;103:95-99.
  7. Smith, C. M., Swash, M., Exton-Smith, A. N., Phillips, M. J., Overstall, P. W., Piper, M. E., and Bailey, M. R. Choline therapy in Alzheimer's disease. Lancet 8-5-1978;2(8084):318. PubMed
  8. Morrison, L. M. and W. F. Gonzales. Choline in coronary atherosclerosis. Amer.Heart J. 1950;39:729.
  9. Christie, J. G. Blackburn 1. M. Glen A. I. M. Zeisel S. Shering A. & Yates C. M. Effects of choline and lecithin on CSF choline levels and on cognitive functioning in patients with presenile dementia of the Alzheimer type. Nutrition and the brain 1979;5
  10. Sidhu N, Davies S, Nadarajah A, et al. Oral choline supplementation for postoperative pain. Br J Anaesth 2013;111(2):249-55. PubMed
  11. Wozniak JR, Fuglestad AJ, Eckerle JK, et al. Choline supplementation in children with fetal alcohol spectrum disorders has high feasibility and tolerability. Nutr Res. 2013;33(11):897-904. PubMed
  12. Wozniak JR, Fuglestad AJ, Eckerle JK, et al. Choline supplementation in children with fetal alcohol disorders: a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2015;102(5): 1113-25.
  13. Ross RG, Hunter SK, McCarthy L, et al. Perinatal choline effects on neonatal pathophysiology related to later schizophrenia risk. Am J Psychiatry. 2013;170(3):290-8. PubMed
  14. Food and Nutrition Board, Institute of Medicine. Choline. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B-6, Vitamin B-12, Pantothenic Acid, Biotin, and Choline. Washington D.C.: National Academy Press; 1998:390-422.

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 Choline and Methazolamide Together: Common Questions

Is it safe to take Choline with Methazolamide?
We do not list a known interaction between Choline and Methazolamide. 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 Choline and Methazolamide have any of the same side effects?
Yes — our sources link each of them separately to 5 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.
How was the Choline and Methazolamide combination checked?
Interactions in our licensed database are recorded against drug classes. Methazolamide is filed under 5 classifications, and Choline has documented interactions with 1 drug class — none of Methazolamide'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 Choline interact with any other medications?
Yes. Choline has 16 documented drug interactions in our database — Methazolamide 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 Methazolamide interact with any supplements?
Yes. Methazolamide has documented interactions with 218 supplements in our database — Choline is not one of them. The Methazolamide 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

Choline monograph Uses, safety profile, and every drug interaction in one place Methazolamide drug information The full plain-English guide to this medication Methazolamide supplement interactions Every supplement checked against Methazolamide, 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 14 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Methazolamide and Choline?

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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.