HYDROPANE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for HYDROPANE (HYDROPANE).
Thiazide diuretic; inhibits sodium chloride cotransporter in distal convoluted tubule, increasing excretion of sodium and water, and reducing plasma volume.
| Metabolism | Hepatic CYP450 metabolism (minimal); not extensively metabolized; excreted primarily unchanged in urine. |
| Excretion | Renal (approximately 50% as unchanged drug) and hepatic metabolism to inactive metabolites; fecal elimination accounts for about 10%. |
| Half-life | Terminal elimination half-life is approximately 8-15 hours in patients with normal renal function; may be prolonged in renal impairment. |
| Protein binding | Highly bound to plasma proteins (>95%), primarily to albumin. |
| Volume of Distribution | Apparent volume of distribution is approximately 1 L/kg, suggesting extensive tissue distribution. |
| Bioavailability | Oral bioavailability is approximately 70% due to first-pass metabolism. |
| Onset of Action | Oral: diuresis begins within 1 hour; peak effect at 2-3 hours. |
| Duration of Action | Duration of diuretic effect is about 6-12 hours after oral administration. |
| Molecular Weight | 338.77 |
50–100 mg orally once daily, maximum 200 mg daily
| Dosage form | SYRUP |
| Renal impairment | GFR <15 mL/min: not recommended. GFR 15–29 mL/min: 25 mg once daily. GFR 30–59 mL/min: no adjustment. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: not recommended. |
| Pediatric use | 1–2 mg/kg orally once daily; maximum 50 mg daily |
| Geriatric use | Start at 25 mg orally once daily; titrate to effect, max 100 mg daily, monitor electrolytes and renal function. |
| 1st trimester | Avoid due to risk of oligohydramnios and fetal renal dysfunction; may cause fetal diuresis. |
| 2nd trimester | Avoid; animal studies suggest teratogenicity risk; human data limited. |
| 3rd trimester | Avoid; may cause oligohydramnios, neonatal jaundice, thrombocytopenia, and electrolyte disturbances. |
Clinical note
Comprehensive clinical and safety monograph for HYDROPANE (HYDROPANE).
| Placental transfer | Crosses the placenta; detected in fetal plasma and amniotic fluid. |
| Breastfeeding | Chlorthalidone is excreted into breast milk in low amounts; however, due to potential for adverse effects in nursing infants (e.g., electrolyte disturbances, dehydration), use with caution and monitor infant for signs of diuresis. |
| Lactation Rating |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
AnuriaHypersensitivity to chlorthalidone or sulfonamidesSevere renal impairment (CrCl <30 mL/min)Hepatic coma
| Precautions | Hypokalemia, Hypomagnesemia, Hyperuricemia, Hyperglycemia, Hyperlipidemia, Volume depletion/hypotension, Sensitivity to sulfonamides (may cause sulfonamide allergy cross-reaction), Renal impairment, Electrolyte monitoring required |
| Food/Dietary | Avoid excessive salt intake to reduce edema; limit alcohol. Grapefruit juice may enhance diuretic effect. Potassium-rich foods (bananas, oranges) may be recommended to counteract hypokalemia. |
| Clinical Pearls |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Not associated with major congenital malformations. Second and third trimesters: May cause fetal hypotension, renal impairment, oligohydramnios, and skull ossification defects. Avoid in pregnancy-induced hypertension due to reduced placental perfusion. |
| Fetal Monitoring | Monitor maternal blood pressure, serum electrolytes, renal function, and fetal growth ultrasound for oligohydramnios. |
| Fertility Effects | No significant impact on fertility reported; reversible effects on reproductive function in animal studies at high doses. |
| Hydrochlorothiazide in HYDROPANE causes hypokalemia, hyponatremia, and hypercalcemia. Monitor electrolytes, especially in elderly. Onset diuresis 2 hours, peak 4 hours, duration 6-12 hours. Avoid in sulfa allergy, anuria, or severe renal impairment. May exacerbate gout, diabetes, and hyperlipidemia. |
| Patient Advice | Take in the morning to avoid nocturia. · Monitor for signs of electrolyte imbalance: muscle cramps, weakness, irregular heartbeat. · Avoid prolonged sun exposure; use sunscreen due to photosensitivity. · Report symptoms of gout (joint pain) or high blood sugar (increased thirst, urination). · Do not stop abruptly; may cause rebound hypertension. |