ORETICYL 50

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ORETICYL 50 (ORETICYL 50).

How it works

Hydrochlorothiazide inhibits the Na+/Cl- cotransporter in the distal convoluted tubule of the kidney, reducing sodium and chloride reabsorption and increasing diuresis.

What the body does with it

Metabolism	Minimally metabolized; eliminated mainly unchanged by renal tubular secretion.
Excretion	Renal: ~95% (50% as unchanged drug, remainder as inactive metabolites); Biliary/fecal: <5%.
Half-life	Terminal elimination half-life: 6–15 hours (mean 10 hours), prolonged in renal impairment (up to 24–30 hours) and elderly.
Protein binding	Hydrochlorothiazide: ~40–70% bound to albumin.
Volume of Distribution	Hydrochlorothiazide: Vd 0.8–1.0 L/kg, indicating distribution into total body water.
Bioavailability	Oral: ~65–75% (hydrochlorothiazide); absorption reduced by food.
Onset of Action	Oral: diuresis begins within 1–2 hours; peak effect at 4–6 hours.
Duration of Action	Oral: diuretic effect lasts 6–12 hours; antihypertensive effect persists for up to 24 hours with continuous dosing.

Classification & Brands

Dosing & administration

Hydrochlorothiazide 50 mg orally once daily in the morning; may increase to 100 mg daily in divided doses.

Dosage form	TABLET
Renal impairment	Contraindicated if GFR <30 mL/min. For GFR 30-50 mL/min: reduce dose to 25 mg daily; monitor electrolytes.
Liver impairment	Child-Pugh A: no adjustment. Child-Pugh B or C: avoid due to risk of electrolyte disturbances and hepatic encephalopathy; if necessary, use with caution at 25 mg daily.
Pediatric use	Not established for ages <2 years. For ages 2-12: 1-2 mg/kg/day in 1-2 divided doses; maximum 50 mg/day.
Geriatric use	Start at 12.5-25 mg daily; monitor for hypotension, electrolyte imbalance, and renal function 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 ORETICYL 50 (ORETICYL 50).

Breastfeeding	Excreted in breast milk in low amounts; M/P ratio unknown. Considered compatible with breastfeeding by AAP, but observe infant for electrolyte imbalances and jaundice.
Teratogenic Risk	First trimester: Possible association with oral clefts and neural tube defects based on limited human data. Second/third trimesters: Risk of fetal renal impairment, oligohydramnios, and neonatal thrombocytopenia. Thiazide diuretics may cause electrolyte disturbances in the neonate.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Serious Effects

Absolute Contraindications

["Anuria","Hypersensitivity to hydrochlorothiazide or sulfonamides"]

Clinical Precautions

Precautions

["Hypokalemia","Hyperuricemia","Photosensitivity","Electrolyte disturbances","Sulfonamide allergy cross-reactivity"]

Clinical Tips & Counseling

Drug interactions

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ORETICYL 50

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ORETICYL 50 (ORETICYL 50).

How it works

Hydrochlorothiazide inhibits the Na+/Cl- cotransporter in the distal convoluted tubule of the kidney, reducing sodium and chloride reabsorption and increasing diuresis.

What the body does with it

Metabolism	Minimally metabolized; eliminated mainly unchanged by renal tubular secretion.
Excretion	Renal: ~95% (50% as unchanged drug, remainder as inactive metabolites); Biliary/fecal: <5%.
Half-life	Terminal elimination half-life: 6–15 hours (mean 10 hours), prolonged in renal impairment (up to 24–30 hours) and elderly.
Protein binding	Hydrochlorothiazide: ~40–70% bound to albumin.
Volume of Distribution	Hydrochlorothiazide: Vd 0.8–1.0 L/kg, indicating distribution into total body water.
Bioavailability	Oral: ~65–75% (hydrochlorothiazide); absorption reduced by food.
Onset of Action	Oral: diuresis begins within 1–2 hours; peak effect at 4–6 hours.
Duration of Action	Oral: diuretic effect lasts 6–12 hours; antihypertensive effect persists for up to 24 hours with continuous dosing.

Classification & Brands

Dosing & administration

Hydrochlorothiazide 50 mg orally once daily in the morning; may increase to 100 mg daily in divided doses.

Dosage form	TABLET
Renal impairment	Contraindicated if GFR <30 mL/min. For GFR 30-50 mL/min: reduce dose to 25 mg daily; monitor electrolytes.
Liver impairment	Child-Pugh A: no adjustment. Child-Pugh B or C: avoid due to risk of electrolyte disturbances and hepatic encephalopathy; if necessary, use with caution at 25 mg daily.
Pediatric use	Not established for ages <2 years. For ages 2-12: 1-2 mg/kg/day in 1-2 divided doses; maximum 50 mg/day.
Geriatric use	Start at 12.5-25 mg daily; monitor for hypotension, electrolyte imbalance, and renal function 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 ORETICYL 50 (ORETICYL 50).

Breastfeeding	Excreted in breast milk in low amounts; M/P ratio unknown. Considered compatible with breastfeeding by AAP, but observe infant for electrolyte imbalances and jaundice.
Teratogenic Risk	First trimester: Possible association with oral clefts and neural tube defects based on limited human data. Second/third trimesters: Risk of fetal renal impairment, oligohydramnios, and neonatal thrombocytopenia. Thiazide diuretics may cause electrolyte disturbances in the neonate.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Serious Effects

Absolute Contraindications

["Anuria","Hypersensitivity to hydrochlorothiazide or sulfonamides"]

Clinical Precautions

Precautions

["Hypokalemia","Hyperuricemia","Photosensitivity","Electrolyte disturbances","Sulfonamide allergy cross-reactivity"]

Clinical Tips & Counseling

Drug interactions

Loading safety data…