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Medically reviewed by Last updated on May 17, 2020.


(bal SAL a zide)

Index Terms

  • Balsalazide Disodium

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule, Oral, as disodium:

Colazal: 750 mg

Generic: 750 mg

Tablet, Oral, as disodium:

Giazo: 1.1 g [DSC]

Brand Names: U.S.

  • Colazal
  • Giazo [DSC]

Pharmacologic Category

  • 5-Aminosalicylic Acid Derivative
  • Anti-inflammatory Agent


Balsalazide is a prodrug, converted by bacterial azoreduction to 5-aminosalicylic acid (mesalamine, active), 4-aminobenzoyl-β-alanine (inert), and their metabolites. 5-aminosalicylic acid may decrease inflammation by blocking the production of arachidonic acid metabolites topically in the colon mucosa.


Very low and variable; in children, reported systemic absorption of 5-ASA (active) lower than adults (Cmax: 67% lower, AUC: 64% lower); time to steady ~2 weeks in pediatric and adult patients


Azoreduced in the colon to 5-aminosalicylic acid (active), 4-aminobenzoyl-β-alanine (inert), and N-acetylated metabolites


Feces (65% as 5-aminosalicylic acid, 4-aminobenzoyl-β-alanine, and N-acetylated metabolites); urine (<16% as N-acetylated metabolites); Parent drug: Urine or feces (<1%)

Time to Peak

Balsalazide: Capsule: 1 to 2 hours; Tablet: 0.5 hours

Half-Life Elimination

Primary effect is topical (colonic mucosa); therapeutic effect appears not to be influenced by the systemic half-life of balsalazide (1.9 hours) or its metabolites (5-ASA [9.5 hours], N-Ac-5-ASA [10.4 hours])

Protein Binding

Balsalazide: ≥99%

Special Populations Note

Ulcerative colitis: May have increased AUC.

Use: Labeled Indications

Ulcerative colitis:

Capsule (Colazal): Treatment of mildly to moderately active ulcerative colitis in patients ≥5 years of age.

Tablet (Giazo): Treatment of mildly to moderately active ulcerative colitis in male patients ≥18 years of age.

Limitations of use: Efficacy of Giazo has not been demonstrated in females.

Off Label Uses

Ulcerative colitis, remission maintenance

Data from a meta-analysis of randomized, double-blind, placebo controlled trials support the use of balsalazide for 6 to 12 months for remission maintenance in ulcerative colitis [Ford 2011].

Based on the American Gastroenterological Association guidelines on the management of mild to moderate ulcerative colitis, balsalazide is an option for remission maintenance in patients with extensive mild to moderate ulcerative colitis; however, evidence was low quality due to imprecision and indirectness.


Hypersensitivity to balsalazide or its metabolites, aminosalicylates, salicylates, or any component of the formulation.

Dosing: Adult

Note: Giazo has been discontinued in the United States for more than 1 year.

Ulcerative colitis, remission induction: Oral:

Capsule: 2.25 g 3 times daily for 8 to 12 weeks.

Tablet: Males: 3.3 g twice daily for up to 8 weeks.

Ulcerative colitis, remission maintenance (off-label use): Capsule: 1.5 or 3 g twice daily for 6 to 12 months (Ford 2011).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Giazo has been discontinued in the US for >1 year.

Ulcerative colitis:

Children ≥5 years and Adolescents ≤17 years: Oral: Capsules:

2.25 g (three 750 mg capsules) 3 times daily (total daily dose: 6.75 g/day) for up to 8 weeks.


750 mg (one capsule) 3 times daily (total daily dose: 2.25 g/day) for up to 8 weeks.

Note: Multicenter, double-blind clinical trial in pediatric patients (n=68, ages 5 to 17 years) showed clinical improvement in both treatment groups (2.25 g/day and 6.75 g/day); there was not a statistical difference in clinical response between the two treatment groups (Quiros 2009).

Adolescents ≥18 years: Oral:

Capsule: 2.25 g (three 750 mg capsules) 3 times daily (total daily dose: 6.75 g/day) for up to 8 to 12 weeks.

Tablet: Males: 3.3 g (three 1.1 g tablets) twice daily (total daily dose: 6.6 g/day) for up to 8 weeks.


Oral: May administer with or without food. Maintain adequate hydration during therapy (to minimize nephrolithiasis risk).

Capsule: Swallow whole; do not cut, break, crush, or chew. May also be opened and sprinkled on ~10 mL of applesauce if patient cannot swallow whole; mix contents within the applesauce. Applesauce mixture may be chewed; swallow immediately, do not store mixture for later use. When sprinkled on food, may cause staining of teeth or tongue.

Dietary Considerations

Some products may contain sodium.


Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).

Drug Interactions

Cardiac Glycosides: 5-Aminosalicylic Acid Derivatives may decrease the serum concentration of Cardiac Glycosides. Monitor therapy

Heparin: 5-Aminosalicylic Acid Derivatives may enhance the adverse/toxic effect of Heparin. Specifically, the risk for bleeding/bruising may be increased. Monitor therapy

Heparins (Low Molecular Weight): 5-Aminosalicylic Acid Derivatives may enhance the adverse/toxic effect of Heparins (Low Molecular Weight). Specifically, the risk for bleeding/bruising may be increased. Monitor therapy

Myelosuppressive Agents: 5-Aminosalicylic Acid Derivatives may enhance the myelosuppressive effect of Myelosuppressive Agents. Monitor therapy

Nonsteroidal Anti-Inflammatory Agents: May enhance the nephrotoxic effect of 5-Aminosalicylic Acid Derivatives. Monitor therapy

Thiopurine Analogs: 5-Aminosalicylic Acid Derivatives may enhance the myelosuppressive effect of Thiopurine Analogs. 5-Aminosalicylic Acid Derivatives may increase serum concentrations of the active metabolite(s) of Thiopurine Analogs. Specifically, exposure to the active 6-thioguanine nucleotides (6-TGN) may be increased. Monitor therapy

Varicella Virus-Containing Vaccines: 5-Aminosalicylic Acid Derivatives may enhance the adverse/toxic effect of Varicella Virus-Containing Vaccines. The primary concern is the potential development of Reye's Syndrome, a condition that has been associated with the use of salicylates in children with varicella infections. Management: Avoid administration of salicylates for at least 6 weeks after adminstration of a varicella virus-containing vaccine. Consider therapy modification

Test Interactions

May cause falsely elevated urinary normetanephrine levels when measured by liquid chromatography with electrochemical detection (due to similarity in the chromatograms of normetanephrine and mesalamine’s main metabolite, N-acetylaminosalicylic acid).

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.


Gastrointestinal: Abdominal pain (≤12%), upper abdominal pain (children: 13%)

Nervous system: Headache (8% to 15%)

1% to 10%:

Gastrointestinal: Abdominal cramps (adults: 1%), anorexia (adults: 2%), constipation (adults: ≤1%), diarrhea (≤9%), dyspepsia (adults: 2%), exacerbation of ulcerative colitis (1% to 7%), flatulence (adults: ≤2%), hematochezia (children: 4%), nausea (4% to 5%), stomatitis (children: 3%), vomiting (≤10%), xerostomia (adults: ≤1%)

Genitourinary: Dysmenorrhea (children: 3%), urinary tract infection (adults: 1% to 4%)

Hematologic & oncologic: Anemia (adults: 4%)

Nervous system: Fatigue (≤4%), insomnia (adults: 2%)

Neuromuscular & skeletal: Arthralgia (adults: ≤4%), musculoskeletal pain (adults: 2%), myalgia (adults: ≤1%)

Respiratory: Cough (2% to 3%), flu-like symptoms (children: 4%; adults: 1%), nasopharyngitis (children: 6%), pharyngitis (adults: 2%), pharyngolaryngeal pain (3% to 4%), respiratory infection (adults: 4%), rhinitis (adults: 2%)

Miscellaneous: Fever (≤6%)


Cardiovascular: Facial edema, increased blood pressure, increased heart rate

Dermatologic: Erythema nodosum, skin rash

Gastrointestinal: Bowel urgency, fecal impaction, gastroenteritis, gastroesophageal reflux disease

Hepatic: Increased serum aspartate aminotransferase

Nervous system: Dizziness, lethargy, malaise, pain

Neuromuscular & skeletal: Back pain

Respiratory: Dyspnea, upper respiratory tract infection

Miscellaneous: Swelling


Cardiovascular: Myocarditis, pericarditis, vasculitis

Dermatologic: Alopecia, pruritus

Endocrine & metabolic: Kawasaki-like syndrome

Gastrointestinal: Pancreatitis

Hepatic: Cholestatic jaundice, hepatic cirrhosis, hepatic failure, hepatic injury, hepatic necrosis, hepatotoxicity, hyperbilirubinemia, increased liver enzymes, jaundice

Renal: Interstitial nephritis, renal failure syndrome

Respiratory: Bronchopneumonia, pleural effusion, pneumonia (with and without eosinophilia)


Concerns related to adverse effects:

• Hypersensitivity reactions: Mesalamine-induced hypersensitivity reactions have been reported and may include internal organ involvement, such as hepatitis, myocarditis, pericarditis, nephritis, hematologic abnormalities, and/or pneumonitis. Monitor for signs and symptoms of hypersensitivity; discontinue treatment if hypersensitivity occurs.

• Intolerance syndrome: May cause an acute intolerance syndrome (cramping, acute abdominal pain, bloody diarrhea; sometimes fever, headache, rash); may be hard to discern from an exacerbation; monitor for worsening of symptoms, and discontinue immediately if syndrome occurs or is suspected.

• Photosensitivity: Use with caution in patients with preexisting skin conditions (including atopic dermatitis and atopic eczema); severe photosensitivity reactions have been reported. Use skin protection (protective clothing and broad-spectrum sunscreen) and avoid prolonged exposure to sunlight and ultraviolet light.

• Renal effects: Renal impairment (including minimal change disease, acute and chronic interstitial nephritis, and renal failure) has been reported. A renal function evaluation is recommended prior to initiation of therapy and periodically during treatment. Evaluate risk versus benefit in patients with renal impairment, history of renal disease, or concurrently taking nephrotoxic medications. Cases of nephrolithiasis (including stones with 100% mesalamine content) have occurred with mesalamine use. Stones may be radiotransparent and undetectable by standard imaging. Ensure patients are adequately hydrated during therapy.

• Staining: May cause staining of teeth or tongue if capsule is opened and sprinkled on food.

• Sulfasalazine hypersensitivity: Patients with hypersensitivity to sulfasalazine may react to mesalamine.

Disease-related concerns:

• GI tract obstruction: Avoid use of capsules in patients at risk for upper GI tract obstruction (eg, pyloric stenosis); may cause prolonged gastric retention and delay release of drug in the colon.

• Hepatic impairment: Evaluate risk versus benefit of therapy in patients with hepatic impairment; hepatic failure has been observed with other mesalamine (5-aminosalicylic acid) products.

• Renal impairment: Use with caution in patients with renal impairment, with a history of renal disease, or on nephrotoxic medications.

Special populations:

• Elderly: Use with caution in elderly patients; uncontrolled studies and postmarketing reports suggest an increased incidence of blood dyscrasias (ie, agranulocytosis, neutropenia, pancytopenia) in patients >65 years of age taking mesalamine-containing products.

Monitoring Parameters

Renal function (prior to and periodically during therapy); CBC (particularly in elderly patients); hepatic function; signs/symptoms of worsening acute intolerance syndrome or hypersensitivity reactions.

Pregnancy Considerations

Mesalamine (5-aminosalicylic acid) is the active metabolite of balsalazide; mesalamine is known to cross the placenta. Refer to the mesalamine monograph for additional information.

Patient Education

What is this drug used for?

• It is used to treat ulcerative colitis.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Headache

• Stomach pain or diarrhea

• Upset stomach or throwing up

• Nose or throat irritation

• Common cold symptoms

• Joint pain

• Feeling tired or weak

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Liver problems like dark urine, feeling tired, not hungry, upset stomach, stomach pain, light-colored stools, throwing up, or yellow skin or eyes

• Kidney problems like unable to pass urine, blood in the urine, change in amount of urine passed, or weight gain

• Kidney stones like back pain, belly pain, or blood in the urine

• Ulcerative colitis like severe stomach pain or cramps; bloody stools; fever; headache; or rash

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

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