Olsalazine: uses, dosing, side effects & brands
Olsalazine is an aminosalicylate sold in the U.S. under one brand, for ulcerative colitis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Aminosalicylate
- Treats
- Ulcerative Colitis
- Available as
- Capsule
- Sold as
- Dipentum
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
How olsalazine is dosed
From the FDA label for Dipentum (application NDA019715). Other olsalazine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Evaluate renal function before initiating therapy with DIPENTUM [see Warnings and Precautions (5.1) ]. The recommended dosage is 500 mg orally twice daily. Drink an adequate amount of fluids during treatment [see Warnings and Precautions (5.7) ] . • Evaluate renal function prior to initiation of DIPENTUM and periodically while on therapy. ( 2 , 5.1 ) • The recommended dosage is 500 mg orally twice daily. ( 2 ) • Drink an adequate amount of fluids. ( 2 , 5.7 )
Olsalazine side effects
The following clinically significant adverse reactions are described elsewhere in the labeling: • Renal impairment [see Warnings and Precautions (5.1) ] • Mesalamine-induced acute intolerance syndrome [see Warnings and Precautions (5.2) ] • Hypersensitivity reactions [see Warnings and Precautions (5.3) ] • Hepatic failure [see Warnings and Precautions (5.4) ] • Severe cutaneous adverse reactions [see Warnings and Precautions (5.5) ] • Photosensitivity [see Warnings and Precautions (5.6) ] • Nephrolithiasis [see Warnings and Precautions (5.7) ] The following adverse reactions have been identified from clinical studies or postmarketing reports of olsalazine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. In double-blind, placebo- and active-controlled clinical trials of ulcerative colitis, discontinuations due to adverse reactions were reported in 10% of DIPENTUM-treated patients (N=441) and 7% of placebo-treated patients (N=208). Both sulfasalazine-tolerant and intolerant patients were included. The most common adverse reactions leading to discontinuation in DIPENTUM-treated patients were diarrhea/loose stools (6%), abdominal pain (1%), and rash/itching (1%). In these controlled trials, adverse reactions reported in 1% or…
Who shouldn’t take olsalazine
DIPENTUM is contraindicated in patients with known or suspected hypersensitivity to salicylates, aminosalicylates, or to any of the excipients in DIPENTUM [see Warnings and Precautions (5.3) , Description (11) ] . Known or suspected hypersensitivity to salicylates or aminosalicylates or to any of the ingredients of DIPENTUM. ( 4 , 5.3 )
Olsalazine drug interactions
Nephrotoxic Agents including Non-Steroidal Anti-inflammatory Drugs (NSAIDs) : Increased risk of nephrotoxicity; monitor for changes in renal function and mesalamine-related adverse reactions. ( 7.1 ) • Azathioprine or 6-Mercaptopurine : Increased risk of blood dyscrasias; monitor complete blood cell counts and platelet counts. ( 7.2 ) • Low Molecular Weight Heparins or Heparinoids : Increased risk of bleeding following neuraxial anesthesia; if possible, discontinue DIPENTUM or closely monitor for bleeding. ( 7.1 ) • Varicella Vaccine : Avoid use for 6 weeks after vaccination. ( 7.4 ) 7.1 Nephrotoxic Agents, Including Non-Steroidal Anti-Inflammatory Drugs The concurrent use of mesalamine with known nephrotoxic agents, including non‑steroidal anti‑inflammatory drugs (NSAIDs), may increase the risk of nephrotoxicity. Monitor patients taking nephrotoxic drugs for changes in renal function and mesalamine-related adverse reactions [see Warnings and Precautions (5.1) ] . 7.2 Azathioprine or 6-Mercaptopurine The concurrent use of mesalamine with azathioprine or 6‑mercaptopurine and/or any other drugs known to cause myelotoxicity (e.g., thioguanine) may increase the risk for blood disorders, bone marrow failure, and associated complications. If concomitant use of DIPENTUM and azathioprine or 6-mercaptopurine cannot be avoided, monitor blood tests, including complete blood cell counts and platelet counts. 7.3 Low Molecular Weight Heparins or Heparinoids The co-administration of salicylates and low molecular weight heparins or heparinoids may result in an increased risk of bleeding (i.e., hematomas) following neuraxial anesthesia. Discontinue DIPENTUM prior to the initiation of a low molecular weight heparin or heparinoid. If this is not possible, it is recommended to monitor patients closely for bleeding. 7.4 Varicella Vaccine Avoid DIPENTUM, and other salicylates, for six weeks after the varicella vaccine to avoid a possible increased risk of developing Reye’s syndrome. 7.5 Interference With Urinary Normetanephrine Measurements Use of DIPENTUM, which is converted to mesalamine, may lead to spuriously elevated test results when measuring urinary normetanephrine by liquid chromatography with electrochemical detection [see Warnings and Precautions (5.8) ] . Consider an alternative, selective assay for normetanephrine.
Every olsalazine product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Dipentum.
What olsalazine pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| DIPENTUM;250;mg | 250 mg | brown | capsule | — |
| DIPENTUM;250;mg | 250 mg | white | oval | — |
| DIPENTUM;250;mg | 250 mg | white | capsule | — |
Olsalazine and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for olsalazine: levels in milk, effects in breastfed infants, and the drugs it would consider insteadLimited data indicate that olsalazine is poorly excreted into breastmilk. However, olsalazine is a mesalamine prodrug. Rather high levels of the mesalamine metabolite N-acetyl-5-ASA appear in breastmilk and its effects on breastfed infants are unknown. A few cases of diarrhea have been reported in infants exposed to mesalamine, although the rate is not high. Most experts consider mesalamine derivatives to be acceptable during breastfeeding. If olsalazine is required by the mother, it is not a reason to discontinue breastfeeding, but carefully observe breastfed infants for diarrhea during maternal use of olsalazine.
National Institute of Child Health and Human Development, record revised December 15, 2025. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about olsalazine
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 22 reports naming olsalazine, and the FDA flagged 59% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- drug eruption3 reports
- erythema3 reports
- neuropathy peripheral3 reports
- rash maculo-papular3 reports
- cataract2 reports
- colitis ulcerative2 reports
- diarrhoea2 reports
- intentional product use issue2 reports
Read these as a signal, not a rate. A report does not mean olsalazine caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is olsalazine?
The active ingredient in DIPENTUM (olsalazine sodium) is the sodium salt of a salicylate, disodium 3,3'-azobis (6-hydroxybenzoate) a compound that is effectively bioconverted to mesalamine (5-aminosalicylic acid,5-ASA), an aminosalicylate.
What kind of drug is olsalazine?
The FDA classifies olsalazine as an aminosalicylate. Aminosalicylates (5-ASA drugs like mesalamine) act directly on the inflamed lining of the colon, where they are thought to calm the local inflammatory response by blocking several inflammation-driving chemicals and mopping up tissue-damaging free radicals, which helps the gut heal in ulcerative colitis. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take olsalazine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run olsalazine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does olsalazine come in?
Across the brands we track, olsalazine is currently marketed as capsule, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic olsalazine?
We do not currently list a generic-labelled olsalazine product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Olsalazine: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/olsalazine
- MLA
- “Olsalazine: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/olsalazine.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for olsalazine on DailyMed (NIH) ↗.