Drug & supplement interaction

Sodium Bicarbonate + Docusate Calcium, Phenolphthalein

Docusate Calcium, Phenolphthalein brand name: Doxidan (Canadian).

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Sodium Bicarbonate has a moderate interaction with Docusate Calcium, Phenolphthalein. Theoretically, sodium bicarbonate may increase the risk of hypokalemia in patients taking stimulant laxatives.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Sodium Bicarbonate and Docusate Calcium, Phenolphthalein

Here is the interaction we found between these two, with the evidence behind it.

Moderate

STIMULANT LAXATIVES

Why this applies to Docusate Calcium, Phenolphthalein

Docusate Calcium, Phenolphthalein falls under STIMULANT LAXATIVES — the group Sodium Bicarbonate interacts with.

Theoretically, sodium bicarbonate may increase the risk of hypokalemia in patients taking stimulant laxatives.
Long-term use of stimulant laxatives, or acute use of high doses (e.g., in bowel-cleansing regimens), can result in potassium loss and hypokalemia. Orally, use of excessive sodium bicarbonate (such as intake of "tablespoons" of sodium bicarbonate daily or up to one box of baking soda weekly) has been associated with cases of hypokalemia. Furthermore, the most common complication of intravenous sodium bicarbonate is hypokalemia.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to keep in mind with this combo. Your product pairs docusate (a stool softener) with phenolphthalein, an old-school stimulant laxative. Stimulant laxatives, especially with long-term or heavy use, can pull potassium out of your body. Baking soda can do the same thing when taken in large amounts. So the worry is that the two together could drop your potassium too low (hypokalemia), which can leave you feeling weak, tired, crampy, or give you an irregular heartbeat.

This is a theoretical concern based on how these work, not from strong studies, and an occasional half-teaspoon of baking soda for heartburn alongside normal laxative use is unlikely to cause trouble. The real risk shows up with big, frequent doses of either one. If you use both regularly, please check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ritsema GH, Ellers G. Potassium supplements prevent serious hypokalemia in colon cleansing. Clin Radiol 1994;49;874-6.
  2. Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
  3. Garabedian-Ruffalo SM, Ruffalo RL. Drug and nutrient interactions. Am Fam Physician 1986;33:165-74.
  4. Proudfoot, A. T., Krenzelok, E. P., and Vale, J. A. Position Paper on urine alkalinization. J Toxicol Clin Toxicol 2004;42(1):1-26. PubMed
  5. Fitzgibbons, L. J. and Snoey, E. R. Severe metabolic alkalosis due to baking soda ingestion: case reports of two patients with unsuspected antacid overdose. J Emerg Med 1999;17(1):57-61. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Sodium Bicarbonate Also Interacts With Other Medications

Sodium Bicarbonate has 256 moderate known drug interactions in our database — the Docusate Calcium, Phenolphthalein one above is one of them. If you take anything else, check it against the full list below.

Moderate 256 No known interaction 2,574 (incl. Docusate Calcium, Phenolphthalein)
Taking anything else?

Check Another of Your Medications Against Sodium Bicarbonate

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

Everything else you take

See Every Supplement That Interacts With Docusate Calcium, Phenolphthalein

This page covers Sodium Bicarbonate only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Docusate Calcium, Phenolphthalein page lists 46 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Jalap (major), Oleander (major), Alder Buckthorn (moderate) and Aloe (moderate).

By severity: 3 major · 34 moderate · 9 minor.

From our pharmacist’s overview on the Docusate Calcium, Phenolphthalein page

“Anyone taking Doxidan (docusate calcium with phenolphthalein) is already on a stimulant laxative, and many herbal constipation remedies work exactly the same way. That overlap is why this list earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Docusate Calcium, Phenolphthalein interaction page

One more smart check

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

We hold 176 real supplement products containing Sodium Bicarbonate, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sodium Bicarbonate. Your product may carry other ingredients that interact with Docusate Calcium, Phenolphthalein too, on top of Sodium Bicarbonate — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Sodium Bicarbonate and Docusate Calcium, Phenolphthalein 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 Sodium Bicarbonate
Top 25%

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

29 days ago today
Medication Docusate Calcium, Phenolphthalein
Top 25%

#599 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.

Supplement

About Sodium Bicarbonate

What is Sodium Bicarbonate?

  • Heartburn and indigestion (antacid)
  • Athletic performance (exercise buffer)
  • Urine alkalinization
  • Soothing skin irritation or itching (topical baths)
  • Mouth rinse and oral care

Sodium bicarbonate (baking soda) is a simple compound most often used as a fast-acting antacid and, in sports, as a buffer that may help with short, high-intensity exercise. It is generally safe in small, occasional doses, but it is high in sodium and can cause serious problems if overused, so people with heart, kidney, or blood pressure issues should be careful and check with a pharmacist or doctor.

Read the full Sodium Bicarbonate monograph & all interactions
Keep checking

Other Drugs & Sodium Bicarbonate

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

0Major
256Moderate
0Minor
2,573No known interaction
256 Moderate 2,573 No interaction
Moderate

256 interactions

Showing 60 of 256 moderate interactions — see all 256 on the Sodium Bicarbonate page.

No interaction 2,573 drugs checked — show the list

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

Showing the 60 most looked-up of 2,573 medications checked with no known interaction — see the full Sodium Bicarbonate list.

See the full Sodium Bicarbonate interactions page
See every supplement checked against Docusate Calcium, Phenolphthalein, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Sodium Bicarbonate monograph › Uses, safety, and every drug interaction in one place Docusate Calcium, Phenolphthalein supplement interactions › Every supplement checked against Docusate Calcium, Phenolphthalein, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Sodium Bicarbonate and Docusate Calcium, Phenolphthalein Together: Common Questions

Can you take Sodium Bicarbonate with Docusate Calcium, Phenolphthalein?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Sodium Bicarbonate and Docusate Calcium, Phenolphthalein interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Docusate Calcium, Phenolphthalein and Sodium Bicarbonate?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.