GIAZO

Clinical safety rating: caution

Comprehensive clinical and safety monograph for GIAZO (GIAZO).

How it works

Balsalazide is a prodrug that is converted by colonic bacteria into mesalamine (5-aminosalicylic acid), which inhibits prostaglandin and leukotriene production, reducing colonic inflammation.

What the body does with it

Metabolism	Primarily metabolized by colonic bacteria via azoreduction to mesalamine and 4-aminobenzoyl-beta-alanine. Mesalamine undergoes hepatic metabolism via N-acetylation to N-acetyl-5-aminosalicylic acid.
Excretion	Primarily metabolized in the gut mucosa and liver to N-acetyl-5-aminosalicylic acid. Renal excretion of acetylated metabolite accounts for ~25-30% of dose; fecal excretion of parent drug and metabolite ~50-60%. Biliary excretion minimal.
Half-life	Terminal elimination half-life approximately 0.5-1.0 hour for 5-ASA (active); metabolite half-life ~5-10 hours. Clinical context: short half-life necessitates multi-matrix release formulation for once-daily dosing in ulcerative colitis.
Protein binding	5-ASA is ~40-50% bound to plasma proteins (mainly albumin); N-acetyl-5-ASA ~80-90% bound.
Volume of Distribution	Apparent Vd ~0.4 L/kg (based on total 5-ASA), indicating distribution primarily into extracellular fluid.
Bioavailability	Oral (tablet): 5-ASA bioavailability ~20-30% due to extensive presystemic metabolism; the multi-matrix system targets colonic release, reducing systemic exposure. No IV formulation.
Onset of Action	Oral (once-daily): clinical improvement may be observed within 2-4 weeks; full therapeutic effect typically by 8 weeks.
Duration of Action	After absorption, systemic 5-ASA cleared rapidly; topical (colonic) action persists as long as formulation releases drug, designed for ~24-hour coverage with once-daily dosing.

Classification & Brands

Dosing & administration

Adults: 2 tablets (1.2 g) orally three times daily (3.6 g/day) for up to 6 weeks.

Dosage form	TABLET
Renal impairment	Contraindicated in severe renal impairment (eGFR <30 mL/min/1.73 m2); no dose adjustment recommended for mild to moderate impairment.
Liver impairment	No specific guidelines; use caution in severe hepatic impairment (Child-Pugh C).
Pediatric use	Not approved for use in pediatric patients under 18 years of age.
Geriatric use	No specific dose adjustment; monitor renal function and consider increased sensitivity due to age-related decline.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for GIAZO (GIAZO).

Breastfeeding	Mesalamine and its metabolites are excreted into breast milk. M/P ratio not established for balsalazide; for mesalamine, M/P ratio is 0.44. Caution in preterm infants or those with renal impairment. Monitor infant for diarrhea.
Teratogenic Risk	GIAZO (balsalazide disodium) is a prodrug of mesalamine. Mesalamine and its metabolites cross the placenta. FDA Pregnancy Category B. No evidence of teratogenicity in human studies, but limited data in first trimester. In second and third trimesters, risk of maternal anemia and possible fetal renal impairment. Use only if clearly needed.

Warnings & precautions

■ FDA Black Box Warning

No FDA black box warning.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to balsalazide, salicylates, or mesalamine","Severe renal impairment (eGFR <30 mL/min/1.73 m²)","Urinary tract obstruction"]

Clinical Precautions

Precautions

["Renal impairment (risk of nephrotoxicity, including interstitial nephritis)","Pyloric stenosis or gastrointestinal obstruction (delayed transit may cause drug accumulation)","Mesalamine-induced acute intolerance syndrome (cramping, abdominal pain, bloody diarrhea, fever, headache, rash)","Photosensitivity in patients with preexisting skin conditions (e.g., atopic dermatitis, eczema)"]

Clinical Tips & Counseling

Drug interactions

Loading safety data…

GIAZO

Clinical safety rating: caution

Comprehensive clinical and safety monograph for GIAZO (GIAZO).

How it works

Balsalazide is a prodrug that is converted by colonic bacteria into mesalamine (5-aminosalicylic acid), which inhibits prostaglandin and leukotriene production, reducing colonic inflammation.

What the body does with it

Metabolism	Primarily metabolized by colonic bacteria via azoreduction to mesalamine and 4-aminobenzoyl-beta-alanine. Mesalamine undergoes hepatic metabolism via N-acetylation to N-acetyl-5-aminosalicylic acid.
Excretion	Primarily metabolized in the gut mucosa and liver to N-acetyl-5-aminosalicylic acid. Renal excretion of acetylated metabolite accounts for ~25-30% of dose; fecal excretion of parent drug and metabolite ~50-60%. Biliary excretion minimal.
Half-life	Terminal elimination half-life approximately 0.5-1.0 hour for 5-ASA (active); metabolite half-life ~5-10 hours. Clinical context: short half-life necessitates multi-matrix release formulation for once-daily dosing in ulcerative colitis.
Protein binding	5-ASA is ~40-50% bound to plasma proteins (mainly albumin); N-acetyl-5-ASA ~80-90% bound.
Volume of Distribution	Apparent Vd ~0.4 L/kg (based on total 5-ASA), indicating distribution primarily into extracellular fluid.
Bioavailability	Oral (tablet): 5-ASA bioavailability ~20-30% due to extensive presystemic metabolism; the multi-matrix system targets colonic release, reducing systemic exposure. No IV formulation.
Onset of Action	Oral (once-daily): clinical improvement may be observed within 2-4 weeks; full therapeutic effect typically by 8 weeks.
Duration of Action	After absorption, systemic 5-ASA cleared rapidly; topical (colonic) action persists as long as formulation releases drug, designed for ~24-hour coverage with once-daily dosing.

Classification & Brands

Dosing & administration

Adults: 2 tablets (1.2 g) orally three times daily (3.6 g/day) for up to 6 weeks.

Dosage form	TABLET
Renal impairment	Contraindicated in severe renal impairment (eGFR <30 mL/min/1.73 m2); no dose adjustment recommended for mild to moderate impairment.
Liver impairment	No specific guidelines; use caution in severe hepatic impairment (Child-Pugh C).
Pediatric use	Not approved for use in pediatric patients under 18 years of age.
Geriatric use	No specific dose adjustment; monitor renal function and consider increased sensitivity due to age-related decline.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for GIAZO (GIAZO).

Breastfeeding	Mesalamine and its metabolites are excreted into breast milk. M/P ratio not established for balsalazide; for mesalamine, M/P ratio is 0.44. Caution in preterm infants or those with renal impairment. Monitor infant for diarrhea.
Teratogenic Risk	GIAZO (balsalazide disodium) is a prodrug of mesalamine. Mesalamine and its metabolites cross the placenta. FDA Pregnancy Category B. No evidence of teratogenicity in human studies, but limited data in first trimester. In second and third trimesters, risk of maternal anemia and possible fetal renal impairment. Use only if clearly needed.

Warnings & precautions

■ FDA Black Box Warning

No FDA black box warning.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to balsalazide, salicylates, or mesalamine","Severe renal impairment (eGFR <30 mL/min/1.73 m²)","Urinary tract obstruction"]