CAPOZIDE 50/25
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CAPOZIDE 50/25 (CAPOZIDE 50/25).
Captopril is an angiotensin-converting enzyme (ACE) inhibitor that inhibits the conversion of angiotensin I to angiotensin II, reducing vasoconstriction and aldosterone secretion. Hydrochlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, increasing excretion of sodium and water.
| Metabolism | Captopril is metabolized primarily via oxidation to disulfide dimers and captopril-cysteine disulfide. Hydrochlorothiazide is not extensively metabolized; it is excreted largely unchanged in urine. |
| Excretion | Captopril: 95% renal (primarily unchanged). Hydrochlorothiazide: 95% renal (unchanged). |
| Half-life | Captopril: ~2 hours (increased in renal impairment). Hydrochlorothiazide: 6-15 hours (prolonged in renal impairment). Clinical context: dosing interval typically 12-24 hours. |
| Protein binding | Captopril: 25-30% (albumin). Hydrochlorothiazide: 40-68% (albumin). |
| Volume of Distribution | Captopril: 0.7 L/kg (distributes into tissues). Hydrochlorothiazide: 3-4 L/kg (extensive tissue binding). |
| Bioavailability | Captopril: 75% (oral, food reduces by 25-40%). Hydrochlorothiazide: 65-75% (oral). |
| Onset of Action | Captopril: 15-30 minutes oral. Hydrochlorothiazide: 2 hours oral. |
| Duration of Action | Captopril: 6-12 hours (dose-dependent). Hydrochlorothiazide: 6-12 hours. Clinical notes: antihypertensive effect may persist longer with continued use. |
One tablet (captopril 50 mg / hydrochlorothiazide 25 mg) orally once daily; may increase to two tablets daily if needed.
| Dosage form | TABLET |
| Renal impairment | eGFR 30-60 mL/min: reduce dose or extend interval; eGFR <30 mL/min: not recommended (contraindicated). Monitor serum creatinine and potassium. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: initiate at half dose and titrate cautiously; Child-Pugh C: contraindicated due to risk of electrolyte imbalance and hepatic encephalopathy. |
| Pediatric use | Not recommended for pediatric use; safety and efficacy not established. |
| Geriatric use | Start at lowest dose (e.g., 25/12.5 mg), titrate slowly; monitor for hypotension, electrolyte disturbances, and renal function. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CAPOZIDE 50/25 (CAPOZIDE 50/25).
| Breastfeeding | Captopril is excreted in breast milk in low concentrations (M/P ratio approximately 0.012). HCTZ is also excreted in breast milk in small amounts. The combination is considered compatible with breastfeeding, but monitor infant for hypotension, electrolyte imbalances, and renal effects. Use with caution in nursing mothers. |
| Teratogenic Risk | First trimester: Risk of fetal renal damage and oligohydramnios. Second and third trimesters: ACE inhibitors (captopril) are associated with oligohydramnios, fetal renal dysfunction, skull ossification defects, and neonatal hypotension. Hydrochlorothiazide (HCTZ) may cause fetal or neonatal jaundice, thrombocytopenia, and electrolyte imbalances. |
■ FDA Black Box Warning
Fetal toxicity: Drugs acting directly on the renin-angiotensin system (including captopril) can cause fetal morbidity and death if used during the second and third trimesters of pregnancy.
| Serious Effects |
["History of angioedema related to ACE inhibitor therapy","Bilateral renal artery stenosis","Anuria (hydrochlorothiazide component)","Hypersensitivity to captopril, hydrochlorothiazide, or sulfonamides","Pregnancy (second and third trimesters)"]
| Precautions | ["Fetal toxicity","Angioedema","Hypotension and volume depletion","Neutropenia/agranulocytosis","Impaired renal function","Hyperkalemia","Hepatic failure","Cough","Electrolyte imbalance due to hydrochlorothiazide","Sulfonamide hypersensitivity"] |
| Food/Dietary | Avoid high-potassium foods (bananas, oranges, spinach, potatoes) and potassium-containing salt substitutes; monitor potassium levels. Limit alcohol intake as it may potentiate hypotension. Take with food or milk to reduce gastrointestinal upset. |
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| Fetal Monitoring | Monitor maternal blood pressure, renal function, serum electrolytes, and urine protein. Fetal monitoring includes ultrasound for oligohydramnios, fetal growth, and amniotic fluid index. Neonatal monitoring for hypotension, hyperkalemia, and renal function after delivery. |
| Fertility Effects | No significant adverse effects on fertility reported with captopril or HCTZ. ACE inhibitors may rarely cause reversible oligospermia. HCTZ has no known impact on fertility. |
| Clinical Pearls | CAPOZIDE 50/25 combines captopril 50mg and hydrochlorothiazide 25mg. Monitor renal function and serum potassium; risk of acute hypotension after first dose. Avoid in pregnancy (ACEI fetopathy). Use with caution in renal artery stenosis. Check for cough (ACEI) and photosensitivity (thiazide). |
| Patient Advice | Take this medication exactly as prescribed, usually once daily. · Avoid potassium supplements or salt substitutes without consulting your doctor. · Report any swelling of face, lips, or difficulty breathing (angioedema) immediately. · Expect possible dizziness upon standing; rise slowly from sitting/lying. · May cause a persistent dry cough; do not stop without consulting provider. · Avoid prolonged sun exposure; use sunscreen (thiazide increases photosensitivity). · Do not use if pregnant or planning pregnancy; use effective contraception. |