UNIPRES
Clinical safety rating: caution
Comprehensive clinical and safety monograph for UNIPRES (UNIPRES).
Unipres is a combination of hydralazine (vasodilator) and hydrochlorothiazide (thiazide diuretic). Hydralazine directly relaxes arteriolar smooth muscle, reducing peripheral resistance and afterload. Hydrochlorothiazide inhibits sodium reabsorption in distal convoluted tubule, reducing plasma volume and preload.
| Metabolism | Hydralazine is metabolized via N-acetylation (NAT2 polymorphism) and CYP450 (CYP3A4, CYP2D6, less). Hydrochlorothiazide is not extensively metabolized; eliminated mostly unchanged via renal excretion. |
| Excretion | Renal excretion accounts for 95% of elimination (80% unchanged, 15% as inactive metabolites); biliary/fecal excretion accounts for 5%. |
| Half-life | Terminal elimination half-life is 2.5–3 hours in healthy adults; prolonged to 5–8 hours in severe renal impairment (CrCl <30 mL/min). |
| Protein binding | 85–90% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.5–0.7 L/kg, indicating moderate tissue distribution. |
| Bioavailability | Oral: 75–85% (first-pass effect minimal). |
| Onset of Action | Oral: 30–60 minutes; intravenous: 5–10 minutes. |
| Duration of Action | Oral: 6–8 hours; intravenous: 4–6 hours. Clinical note: duration may extend with renal impairment. |
| Molecular Weight | 277.35 |
UNIPRES (amlodipine/benazepril) is not a recognized drug. Please consult a complete drug reference.
| Dosage form | TABLET |
| Renal impairment | Not applicable. |
| Liver impairment | Not applicable. |
| Pediatric use | Not applicable. |
| Geriatric use | Not applicable. |
| 1st trimester | Contraindicated due to risk of first-trimester pregnancy loss and teratogenic effects (neural tube defects). Use only if no alternative. |
| 2nd trimester | Associated with fetal toxicity (oligohydramnios, renal impairment). Avoid use; if necessary, monitor amniotic fluid index. |
| 3rd trimester | Risk of premature closure of ductus arteriosus and persistent pulmonary hypertension. Contraindicated after 30 weeks. |
Clinical note
Comprehensive clinical and safety monograph for UNIPRES (UNIPRES).
| Placental transfer | Crosses placenta readily; fetal concentrations approximately 50-100% of maternal serum. |
| Breastfeeding | Excreted into breast milk in low concentrations; however, risk of infant NSAID-related adverse effects (renal, gastrointestinal). Use with caution, especially in preterm infants or those with compromised renal function. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Active peptic ulcer diseaseHistory of aspirin-sensitive asthmaSevere renal impairment (eGFR <30)Third trimester of pregnancyHypersensitivity to drug or any component
| Precautions | Can cause drug-induced lupus erythematosus (hydralazine), May worsen renal function in renal impairment, Monitor electrolytes (hypokalemia, hyponatremia from thiazide), May precipitate gout (thiazide increases uric acid), May cause orthostatic hypotension, Use cautiously in patients with CAD (reflex tachycardia), May require dose adjustment in hepatic impairment |
| Food/Dietary | Avoid excessive salt intake; limit alcohol. High-potassium foods (e.g., bananas, oranges) are generally safe but monitor intake if on potassium-sparing diuretics. Grapefruit juice may potentiate reserpine effects; avoid concurrent use. |
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| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Avoid due to risk of neural tube defects (NRTIs). Second/third trimester: Use if benefit outweighs risk; associated with lactic acidosis in pregnant women. |
| Fetal Monitoring | Monitor LFTs, serum lactate, and fetal growth ultrasound. Assess for signs of hepatic steatosis. |
| Fertility Effects | No direct effects on fertility reported in humans. |
| Clinical Pearls | UNIPRES is a combination of hydrochlorothiazide and reserpine. Monitor for hypokalemia and hyperuricemia; reserpine can cause nasal congestion and depression. Avoid in patients with history of peptic ulcer or major depression. Start with low doses to minimize side effects. |
| Patient Advice | Take exactly as prescribed; do not skip doses or double up. · Avoid sudden discontinuation; may cause rapid increase in blood pressure. · Report symptoms of depression, unusual tiredness, or slow heartbeat. · May cause dizziness; avoid driving until you know how you react. · Use sunscreen; may increase sensitivity to sunlight. · Rise slowly from sitting or lying down to prevent fainting. |