HYDROMOX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for HYDROMOX (HYDROMOX).
Inhibits the sodium-chloride symporter (NCC) in the distal convoluted tubule of the kidney, reducing sodium and chloride reabsorption and increasing water excretion.
| Metabolism | Primarily excreted unchanged in the urine; minimal hepatic metabolism. |
| Excretion | Renal: 70% unchanged via tubular secretion; biliary/fecal: <10% |
| Half-life | Terminal elimination half-life: 6-9 hours; prolonged to 24-36 hours in renal impairment (CrCl <30 mL/min) |
| Protein binding | 65% bound to albumin and erythrocytes |
| Volume of Distribution | 4 L/kg (extensive tissue distribution, including erythrocytes) |
| Bioavailability | Oral: 65% (first-pass metabolism, food may reduce absorption) |
| Onset of Action | Oral: 2 hours; IV: 15-30 minutes |
| Duration of Action | Oral: 12-24 hours; IV: 6-12 hours; antihypertensive effect peaks at 4-6 weeks |
50-100 mg orally once daily; may increase to 200 mg/day for severe edema.
| Dosage form | TABLET |
| Renal impairment | GFR 30-60 mL/min: reduce dose by 50%; GFR <30 mL/min: contraindicated. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use. |
| Pediatric use | 1-2 mg/kg orally once daily; maximum 50 mg/day. |
| Geriatric use | Initiate at 25 mg orally once daily; titrate cautiously due to risk of electrolyte imbalance and hypotension. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for HYDROMOX (HYDROMOX).
| Breastfeeding | Excreted in human milk in low concentrations. M/P ratio not established. Thiazides may suppress lactation. Use with caution in nursing mothers, weighing benefits against potential risks to the infant (e.g., electrolyte disturbances, hypersensitivity). |
| Teratogenic Risk | Pregnancy Category B. No evidence of teratogenicity in animal studies; limited human data. Thiazide use in pregnancy, especially during first trimester, is generally avoided due to theoretical risk of fetal electrolyte disturbances and reduced placental perfusion. During second and third trimesters, may cause fetal or neonatal jaundice, thrombocytopenia, and electrolyte imbalances. Consider alternative antihypertensives. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Anuria","Sulfonamide allergy (cross-sensitivity with thiazide diuretics)","Hepatic coma or pre-coma","Severe electrolyte imbalance (e.g., hypokalemia, hyponatremia)"]
| Precautions | ["Electrolyte imbalances (hypokalemia, hyponatremia, hypomagnesemia, hypochloremia)","Hyperuricemia and gout","Hypercalcemia","Sulfonamide allergy cross-sensitivity","Orthostatic hypotension","Systemic lupus erythematosus exacerbation","Acute angle-closure glaucoma (rare)"] |
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| Fetal Monitoring | Monitor maternal blood pressure, serum electrolytes (particularly sodium, potassium), and renal function throughout pregnancy. Fetal monitoring for growth and well-being (ultrasound, non-stress test) if used in second/third trimester. Observe neonates for jaundice, thrombocytopenia, and electrolyte abnormalities. |
| Fertility Effects | No known adverse effects on fertility in animal studies. In humans, thiazide diuretics are not associated with impaired fertility. However, electrolyte disturbances may theoretically impact reproductive function. |