Introduction
Giazo (balsalazide disodium) is an oral prodrug aminosalicylate medication specifically designed for targeted delivery to the colon. It is classified as a gastrointestinal anti-inflammatory agent and represents an important therapeutic option in the management of ulcerative colitis. Giazo was developed to provide localized anti-inflammatory effects while minimizing systemic exposure.
Mechanism of Action
Giazo is a prodrug that undergoes bacterial cleavage in the colon to release mesalamine (5-aminosalicylic acid or 5-ASA), its active moiety. Mesalamine acts locally in the colonic mucosa through multiple mechanisms: it inhibits cyclooxygenase and lipoxygenase pathways, reduces prostaglandin and leukotriene production, scavenges reactive oxygen species, and inhibits cytokine production. These actions collectively result in anti-inflammatory effects specifically targeted to the colonic tissue with minimal systemic absorption.
Indications
Giazo is FDA-approved for:
- Treatment of mildly to moderately active ulcerative colitis in patients 5 years of age and older
- Maintenance of remission of ulcerative colitis in adults
Dosage and Administration
Active Ulcerative Colitis:- Adults: 2.25 g three times daily for up to 8 weeks
- Pediatric patients (5-17 years): 2.25 g three times daily for up to 8 weeks
- Adults: 2.25 g three times daily
- Administer orally with or without food
- Capsules should be swallowed whole; do not crush or chew
- For patients who have difficulty swallowing, capsules may be opened and contents sprinkled on applesauce
- Renal impairment: Use with caution; monitor renal function
- Hepatic impairment: No specific dosage adjustment recommended
- Elderly: No specific dosage adjustment recommended
Pharmacokinetics
Absorption: Balsalazide is poorly absorbed from the gastrointestinal tract with less than 1% systemic absorption as intact prodrug. Distribution: The released mesalamine acts locally in the colon with minimal systemic distribution. Metabolism: Cleaved by colonic bacterial azoreductases to release mesalamine and the inert carrier molecule 4-aminobenzoyl-β-alanine. Elimination: Mesalamine is primarily excreted in feces, with renal excretion of absorbed mesalamine and metabolites.Contraindications
- Hypersensitivity to salicylates
- Hypersensitivity to any component of the formulation
- Patients with known aspirin sensitivity
Warnings and Precautions
Renal Effects: Mesalamine has been associated with renal toxicity, including interstitial nephritis. Evaluate renal function at baseline and periodically during treatment. Mesalamine-Induced Acute Intolerance Syndrome: Some patients may experience symptoms resembling ulcerative colitis exacerbation (cramping, acute abdominal pain, bloody diarrhea). Hypersensitivity Reactions: Some patients may develop hypersensitivity reactions including myocarditis, pericarditis, and pleuritis. Hepatic Effects: Rare cases of hepatic failure have been reported; monitor liver function tests. Pulmonary Effects: Interstitial lung disease has been reported with mesalamine-containing products.Drug Interactions
Warfarin: Mesalamine may potentiate anticoagulant effect; monitor INR closely. Nonsteroidal Anti-inflammatory Drugs (NSAIDs): May increase risk of nephrotoxicity. Azathioprine/6-Mercaptopurine: Concomitant use may increase risk of blood dyscrasias. Thiopurine Methyltransferase (TPMT) Inhibitors: May affect metabolism of concomitant thiopurine drugs.Adverse Effects
Common (≥1%):- Headache (8%)
- Abdominal pain (6%)
- Nausea (5%)
- Diarrhea (5%)
- Respiratory infection (4%)
- Arthralgia (4%)
- Flatulence (3%)
- Renal impairment (including interstitial nephritis)
- Hepatic failure
- Pancreatitis
- Blood dyscrasias (agranulocytosis, aplastic anemia)
- Pericarditis
- Myocarditis
- Severe cutaneous adverse reactions
Monitoring Parameters
- Renal function (serum creatinine, BUN) at baseline and every 3-6 months during therapy
- Complete blood count periodically
- Liver function tests
- Symptoms of mesalamine intolerance (worsening colitis symptoms)
- Signs of hypersensitivity reactions
- Patient's clinical response and symptom improvement
Patient Education
- Take medication exactly as prescribed; do not crush or chew capsules
- Report any worsening of colitis symptoms, fever, or rash immediately
- Stay well-hydrated during therapy
- Inform all healthcare providers about Giazo use, especially before surgical procedures
- Report any unusual bleeding, bruising, or fatigue
- Notify provider if pregnancy is planned or suspected
- Keep all follow-up appointments for monitoring
- Do not use antacids containing aluminum within 2 hours of Giazo administration
References
1. Sandborn WJ, et al. Balsalazide is superior to mesalamine in the time to improvement of signs and symptoms of acute mild-to-moderate ulcerative colitis. Am J Gastroenterol. 2002;97(6):1398-1407. 2. Pruitt R, et al. Balsalazide is safe and well tolerated in patients with mild to moderate ulcerative colitis. Dig Dis Sci. 2002;47(8):1823-1829. 3. Giazo [package insert]. San Diego, CA: Salix Pharmaceuticals; 2021. 4. Kornbluth A, Sachar DB; Practice Parameters Committee of the American College of Gastroenterology. Ulcerative colitis practice guidelines in adults: American College of Gastroenterology, Practice Parameters Committee. Am J Gastroenterol. 2010;105(3):501-523. 5. Rubin DT, et al. ACG Clinical Guideline: Ulcerative Colitis in Adults. Am J Gastroenterol. 2019;114(3):384-413. 6. FDA Approved Drug Products: Giazo (balsalazide disodium) capsules. Accessed January 2023.