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Olsalazine Side Effects

Medically reviewed by Last updated on Oct 22, 2022.

Applies to olsalazine: oral capsule.

Serious side effects of Olsalazine

Along with its needed effects, olsalazine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking olsalazine:

More common

  • Agitation
  • bloody diarrhea
  • blood in the urine
  • coma
  • confusion
  • dark-colored urine
  • decreased urine output
  • depression
  • dizziness
  • fever
  • general feeling of tiredness or weakness
  • headache
  • hostility
  • increased sensitivity of the skin to sunlight
  • irritability
  • itching, skin rash
  • lethargy
  • light-colored stools
  • muscle twitching
  • nausea
  • pain in the groin or genitals
  • rapid weight gain
  • redness or other discoloration of the skin
  • seizures
  • severe sunburn
  • sharp back pain just below ribs
  • stomach pain
  • swelling of the face, ankles, or hands
  • unusual tiredness or weakness
  • vomiting
  • yellow eyes or skin

Less common

  • Pale skin
  • trouble breathing
  • unusual bleeding or bruising


Incidence not know

  • Blistering, peeling, or loosening of the skin
  • chest pain
  • chills
  • cough
  • diarrhea
  • joint or muscle pain
  • painful or difficult urination
  • red, irritated eyes
  • red skin lesions often with a purple center
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • swelling of the feet or lower legs
  • unsteadiness or awkwardness
  • weakness in the arms, hands, legs, or feet

Other side effects of Olsalazine

Some side effects of olsalazine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • loss of appetite

Less common

  • Aching joints and muscles
  • acid or sour stomach
  • acne
  • anxiety
  • belching
  • bloated or full feeling
  • body aches or pain
  • bone pain
  • congestion
  • constipation
  • coughing
  • cramps
  • difficulty with moving
  • dizziness or drowsiness
  • heartburn
  • hoarseness
  • indigestion
  • muscle stiffness
  • passing of gas
  • shivering
  • sleeplessness
  • sneezing
  • stomach discomfort or upset
  • sweating
  • swelling or inflammation of the mouth
  • swollen joints
  • tender, swollen glands in the neck
  • trouble with sleeping
  • trouble with swallowing
  • unable to sleep
  • voice changes
  • weight loss


  • Decreased interest in sexual intercourse
  • flushing, redness of the skin
  • hair loss or thinning of the hair
  • inability to have or keep an erection
  • loss in sexual ability, desire, drive, or performance
  • unusually warm skin

For Healthcare Professionals

Applies to olsalazine: oral capsule.


The most commonly reported side effects included diarrhea, abdominal pain, cramps, nausea, and headaches.[Ref]


Very common (10% or more): Diarrhea (up to 17%), abdominal pain (up to 10.1%), cramps (10.1%)

Common (1% to 10%): Bloating, heartburn, loose stools, nausea, rectal bleeding, stomatitis, upset stomach, vomiting

Uncommon (0.1% to 1%): Dyspepsia

Frequency not reported: Abdominal pain upper, diarrhea with dehydration, dry mouth, epigastric discomfort, exacerbation/flare in symptoms, flatulence, increased blood in stool, pancreatitis, rectal discomfort[Ref]

Compared to patients given placebo, increased frequency and intensity of diarrhea was reported in patients given 500 mg orally 2 times a day who were also receiving pelvic radiation.[Ref]

Nervous system

Common (1% to 10%): Dizziness, headache, lightheadedness, vertigo

Uncommon (0.1% to 1%): Paresthesia

Frequency not reported: Drowsiness, lethargy, peripheral neuropathy, tremors[Ref]


Common (1% to 10%): Itching, rash

Uncommon (0.1% to 1%): Alopecia, photosensitivity/photosensitivity reaction, pruritus, urticaria

Frequency not reported: Erythema, erythema nodosum[Ref]


Common (1% to 10%): Depression, insomnia

Frequency not reported: Irritability, mood swings[Ref]


Common (1% to 10%): Arthralgia, joint pain

Uncommon (0.1% to 1%): Myalgia

Frequency not reported: Muscle cramps[Ref]


Common (1% to 10%): Upper respiratory infection

Uncommon (0.1% to 1%): Dyspnea

Frequency not reported: Bronchospasm, interstitial lung/pulmonary disease, shortness of breath[Ref]


Common (1% to 10%): Anorexia

Postmarketing reports: Elevated lactate dehydrogenase (LDH)[Ref]


Uncommon (0.1% to 1%): Hepatic enzyme increased

Rare (0.01% to 0.1%): Granulomatous hepatitis, nonspecific, reactive hepatitis

Frequency not reported: ALT elevated beyond normal range, AST elevated beyond normal range, hepatitis, increased bilirubin, mild cholestatic hepatitis

Postmarketing reports: Cholestatic jaundice, cirrhosis, elevated alkaline phosphatase, elevated GGT, hepatic function changes, hepatocellular damage, hepatotoxicity, jaundice, liver failure, liver necrosis[Ref]

Patients who developed granulomatous hepatitis, nonspecific, reactive hepatitis, or mild cholestatic hepatitis had complete recovery after treatment was withdrawn.[Ref]


Uncommon (0.1% to 1%): Thrombocytopenia

Frequency not reported: Anemia, aplastic anemia, eosinophilia, granulocytopenia, hemolysis, hemolytic anemia, leukopenia, lymphopenia, neutropenia, pancytopenia, reticulocytosis[Ref]


A patient developed thyroid disease 9 days after starting treatment and was given propranolol radioactive iodine; the patient then developed nausea and shortness of breath and died 5 days later with signs/symptoms of acute diffuse myocarditis.[Ref]

Uncommon (0.1% to 1%): Tachycardia

Frequency not reported: Chest pains, heart block second degree, hot flashes, hypertension, myocarditis, orthostatic hypotension, palpitations, pericarditis, peripheral edema[Ref]


Uncommon (0.1% to 1%): Pyrexia

Frequency not reported: Chills, fatigue, fever, miscellaneous side effects, rigors, tinnitus[Ref]


Frequency not reported: Dysuria, frequency/urinary frequency, hematuria, impotence, menorrhagia, proteinuria[Ref]


Frequency not reported: Blurred vision, dry eyes, watery eyes[Ref]


Frequency not reported: Interstitial nephritis, nephrotic syndrome[Ref]


Frequency not reported: Angioneurotic edema[Ref]


1. "Product Information. Dipentum (olsalazine)." Meda Pharmaceuticals (2001):

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Cerner Multum, Inc. "Australian Product Information." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.