ALDORIL 15
Clinical safety rating
cautionComprehensive clinical and safety monograph for ALDORIL 15 (ALDORIL 15).
Methyldopa is a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brainstem, decreasing peripheral vascular resistance and blood pressure. Hydrochlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, reducing plasma volume and cardiac output.
| Metabolism | Methyldopa is metabolized in the liver via conjugation and O-methylation; active metabolites include methyldopamine and methylnorepinephrine. Hydrochlorothiazide is not significantly metabolized and is excreted unchanged in urine. |
| Excretion | Renal: ~70% unchanged; biliary/fecal: ~30% as metabolites |
| Half-life | Terminal half-life: 12–17 hours; clinical context: steady-state achieved within 2–3 days; effect persists 12–24 hours |
| Protein binding | ~90%, primarily to albumin |
| Volume of Distribution | 2–4 L/kg; clinical meaning: extensive tissue distribution, concentrating in vascular smooth muscle |
| Bioavailability | Oral: 50–60% (extensive first-pass metabolism) |
| Onset of Action | Oral: 2–4 hours; peak effect at 4–6 hours |
| Duration of Action | Oral: 12–24 hours; clinical notes: antihypertensive effect may persist for 24 hours after single dose |
| Molecular Weight | Methyldopa: 211.22 g/mol; Hydrochlorothiazide: 297.74 g/mol |
1 tablet (hydrochlorothiazide 15 mg, methyldopa 250 mg) orally twice daily; increase as needed up to 2 tablets twice daily.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50 mL/min: maximum 1 tablet twice daily. GFR <30 mL/min: avoid use. |
| Liver impairment | Child-Pugh A: caution, reduce dose. Child-Pugh B: avoid. Child-Pugh C: contraindicated. |
| Pediatric use | Not recommended for pediatric use; safety in children under 12 years not established. |
| Geriatric use | Start with 1 tablet once daily; monitor for hypotension and electrolyte imbalance. Reduce initial dose by 50%. |
| 1st trimester | Avoid; associated with fetal toxicity and oligohydramnios, based on animal data. |
| 2nd trimester | Avoid; may cause fetal hypotension, reduced placental perfusion, and oligohydramnios. |
| 3rd trimester | Avoid; may cause neonatal hypotension, bradycardia, and renal impairment. |
Clinical note
Comprehensive clinical and safety monograph for ALDORIL 15 (ALDORIL 15).
| Placental transfer | Both methyldopa and hydrochlorothiazide cross the placenta; methyldopa achieves fetal concentrations similar to maternal. |
| Breastfeeding | Methyldopa is excreted into breast milk in low amounts; however, hydrochlorothiazide may suppress lactation and cause neonatal electrolyte disturbances. Use with caution. |
| Lactation Rating | L3 - Limited Data |
| Teratogenic Risk | First trimester: No increased risk of major malformations based on limited human data; animal studies show no teratogenicity at clinically relevant doses. Second/third trimesters: Fetal and neonatal adverse effects including oligohydramnios, fetal renal dysfunction, skull ossification delay, and hypotension in the neonate. Avoid use after 20 weeks gestation unless no alternative. |
| Fetal Monitoring | Monitor maternal blood pressure, renal function, serum electrolytes, and CBC. In pregnancy, monitor fetal growth by ultrasound if used after 20 weeks; assess amniotic fluid volume regularly. Watch for signs of neonatal hypotension, bradycardia, and electrolyte disturbances after delivery. |
| Fertility Effects | Methyldopa may cause reversible infertility in men due to decreased libido and impotence. Hydrochlorothiazide has no known direct effect on fertility. In women, no significant impairment of fertility reported. Reproductive studies in animals show no adverse effects on fertility at clinically relevant doses. |
■ FDA Black Box Warning
None
| Serious Effects |
Active hepatic disease (methyldopa component)History of hypersensitivity to methyldopa or hydrochlorothiazideAnuria (hydrochlorothiazide component)
| Precautions | Sedation, usually transient; may impair ability to drive or operate heavy machinery., Positive Coombs test with hemolytic anemia (rare); monitor hematocrit and Coombs test., Hepatotoxicity (hepatic necrosis) with fever, jaundice; discontinue if liver abnormalities occur., Fluid and electrolyte imbalance (hypokalemia, hyponatremia, hypercalcemia) due to thiazide., May precipitate gout in hyperuricemic patients., May exacerbate systemic lupus erythematosus. |
| Food/Dietary | Avoid high-sodium foods as they can reduce antihypertensive efficacy. Thiazides may cause hypokalemia; increase dietary potassium (bananas, orange juice) unless contraindicated. Alcohol may enhance orthostatic hypotension. |
| Clinical Pearls | Aldoril 15 (methyldopa 250mg + hydrochlorothiazide 15mg) is rarely used due to superior alternatives. Monitor for hepatotoxicity, hemolytic anemia, and lupus-like syndrome. Titrate slowly to avoid sedation. Contraindicated in active liver disease, pheochromocytoma, and anuria. |
| Patient Advice | May cause drowsiness; avoid driving until tolerance develops. · Report unexplained fever, jaundice, or dark urine immediately. · Take at bedtime to minimize sedation. · Avoid sudden discontinuation; follow prescribed tapering schedule. · Use sun protection; thiazides increase photosensitivity. |
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