Comprehensive medication guide to Pentasa XR including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$10–$40 copay for generic mesalamine ER (Tier 1–2 on most plans); brand Pentasa may be Tier 3–4 ($60–$150+) and may require prior authorization or step therapy.
Estimated Cash Pricing
$800–$1,200 retail for brand Pentasa XR; as low as $43–$209 with GoodRx or SingleCare discount cards for generic mesalamine ER or brand Pentasa for a 30-day supply.
Medfinder Findability Score
38/100
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Pentasa XR is the brand name for mesalamine extended-release (ER) capsules, manufactured by Takeda Pharmaceuticals. Mesalamine — also known as 5-aminosalicylic acid (5-ASA) — is an aminosalicylate anti-inflammatory drug used to treat ulcerative colitis (UC), an inflammatory bowel disease affecting the colon and rectum. The medication has been FDA-approved since 1987.
Pentasa XR is available as 250 mg and 500 mg extended-release capsules. The standard dose for treating active ulcerative colitis is 1 gram (two 500 mg or four 250 mg capsules) taken four times daily for a total of 4 grams per day. Generic versions (mesalamine ER capsules) are also available from manufacturers including Sun Pharmaceutical Industries.
Pentasa XR is FDA-approved for induction of remission and treatment of mildly to moderately active ulcerative colitis in adults. It is also used off-label in Crohn's disease, particularly following surgical resection, for patients with small bowel involvement where its GI-tract-wide release offers clinical advantages.
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Pentasa XR works by delivering mesalamine (5-ASA) directly to the lining of the gastrointestinal tract, where it acts locally to reduce inflammation. Unlike systemic anti-inflammatory drugs, mesalamine's primary action is at the site of disease — the mucosal lining of the intestines — rather than throughout the entire body.
The mechanism involves inhibiting cyclooxygenase (COX) enzymes and lipoxygenase (LOX) pathways, reducing production of prostaglandins and leukotrienes — the inflammatory signaling molecules elevated in UC flares. This decreases mucosal inflammation, relieves symptoms, and helps maintain remission.
What makes Pentasa XR unique among mesalamine products is its ethylcellulose-coated microsphere delivery system. These microspheres release mesalamine continuously from the duodenum all the way through the colon — unlike pH-dependent formulations (Lialda, Apriso) that only release drug in the colon. This makes Pentasa XR especially suitable for patients with disease extending into the small intestine.
250 mg — extended-release capsule
Four capsules per dose (1 g), four times daily for 4 g/day total
500 mg — extended-release capsule
Two capsules per dose (1 g), four times daily for 4 g/day total
As of 2026, Pentasa XR is experiencing an active shortage. The ASHP officially lists mesalamine extended-release capsules as a current shortage, with Sun Pharmaceutical Industries' 500 mg capsules on back order as of January 2026 with no estimated resupply date as of March 2026. The brand-name Pentasa from Takeda may be available at some pharmacies, but insurance barriers can complicate access.
The 250 mg capsule may have better availability than the 500 mg capsule during the current shortage. Patients should check multiple pharmacy types — chain pharmacies, independent pharmacies, and mail-order options — to find available stock. The shortage has been most pronounced at large chain pharmacies; independent pharmacies with access to multiple wholesalers sometimes have better availability.
To find pharmacies near you that currently have Pentasa XR or mesalamine ER in stock, use medfinder — a service that calls pharmacies on your behalf to check availability for your specific medication, dose, and quantity.
Pentasa XR is not a controlled substance and carries no DEA scheduling restrictions. Any licensed healthcare provider with prescribing authority in their state may prescribe it, including via telehealth. There are no special registration requirements or prescribing restrictions.
Telehealth availability: Because Pentasa XR is not a controlled substance, it is fully available via telehealth in all 50 U.S. states. Many gastroenterology groups and general telehealth platforms (Teladoc, MDLive) can prescribe it without an in-person visit for patients with an established UC diagnosis.
No. Pentasa XR (mesalamine) is not a controlled substance and is not scheduled by the DEA under any federal classification. It has no abuse or dependence potential. This means any licensed prescriber with prescribing authority — including primary care physicians, gastroenterologists, nurse practitioners, and physician assistants — can prescribe Pentasa XR without special DEA registration or restrictions.
Because Pentasa XR is not a controlled substance, it can also be prescribed via telehealth visits in all 50 U.S. states without any additional restrictions. Prescriptions may be refilled without in-person visits in most circumstances.
The most common side effects (occurring in 1% or more of patients in clinical trials) include:
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Lialda
Once-daily mesalamine delayed-release tablet (MMX technology); 2.4–4.8 g daily; targets colon; generic available and widely stocked
Apriso
Once-daily mesalamine ER capsules (1.5 g); pH-dependent colon targeting; also experiencing shortage issues in 2026
Delzicol
Mesalamine delayed-release 400 mg capsules; targets terminal ileum and colon; approved for adults and children ≥5 years
Sulfasalazine
Original 5-ASA agent; split into mesalamine + sulfapyridine in colon; very inexpensive; 30% of patients have side effects from sulfa component
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Azathioprine / 6-Mercaptopurine
majorMesalamine inhibits TPMT enzyme metabolism of thiopurines, increasing toxic metabolite levels and risk of bone marrow suppression; monitor CBC and platelets
Varicella (live) vaccine
majorRisk of Reye's syndrome; avoid mesalamine for 6 weeks after varicella vaccination
NSAIDs (ibuprofen, naproxen)
moderateAdditive nephrotoxicity risk; monitor renal function closely if both are necessary
Proton pump inhibitors (omeprazole, pantoprazole)
moderateMay increase GI pH and affect mesalamine release timing, potentially reducing effectiveness
Nephrotoxic agents (vancomycin, cyclosporine, aminoglycosides)
moderateAdditive kidney damage risk; monitor renal function closely
Warfarin
moderateMesalamine may increase anticoagulant effect; monitor INR when starting or stopping
Pentasa XR (mesalamine extended-release) is a well-established, effective first-line treatment for mild-to-moderate ulcerative colitis with a strong safety track record since its FDA approval in 1987. Its unique pan-GI release mechanism sets it apart from other mesalamine products, making it particularly valuable for patients with disease affecting the small intestine.
However, the 2026 shortage of generic mesalamine ER 500 mg capsules is creating real access challenges. Patients should plan ahead, use all available tools to locate their medication, and work closely with their gastroenterologist to ensure continuous treatment coverage. Switching to the 250 mg capsule or to a therapeutically equivalent alternative may be necessary during the shortage.
If you're struggling to find Pentasa XR at your local pharmacy, medfinder can help by calling pharmacies near you to identify which ones have your specific medication and dosage in stock.
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