ALDOCLOR-250
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ALDOCLOR-250 (ALDOCLOR-250).
Aldoclor-250 is a combination of methyldopa and chlorothiazide. Methyldopa is a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brain, decreasing peripheral vascular resistance and blood pressure. Chlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, increasing urinary output and reducing plasma volume.
| Metabolism | Methyldopa: Primarily hepatic metabolism via catecholamine pathways; conjugated to sulfate and other metabolites. Chlorothiazide: Not extensively metabolized; excreted unchanged in urine. |
| Excretion | Renal (70-80% unchanged), biliary/fecal (15-25% as metabolites); total clearance ~250 mL/min. |
| Half-life | 1.5-3 hours; prolonged in renal impairment (up to 20 hours with CrCl <10 mL/min). |
| Protein binding | 25-40% bound primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.6-1.0 L/kg; indicates distribution into total body water and some tissue binding. |
| Bioavailability | 70-90% (oral); 100% (IV). |
| Onset of Action | Oral: 2-4 hours; IV: 15-30 minutes. |
| Duration of Action | 6-8 hours (oral); 4-6 hours (IV); extended with reduced renal function. |
| Molecular Weight | 323.13 |
250 mg orally twice daily
| Dosage form | TABLET |
| Renal impairment | CrCl >50 mL/min: no adjustment; CrCl 10-50 mL/min: 250 mg once daily; CrCl <10 mL/min: 250 mg every 48 hours |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: use with caution, reduce dose by 50%; Child-Pugh C: avoid use |
| Pediatric use | Not recommended for use in pediatric patients due to lack of safety and efficacy data |
| Geriatric use | Start at lower end of dosing range; monitor renal function closely; adjust dose based on CrCl |
| 1st trimester | Contraindicated due to risk of fetal chloramphenicol toxicity including gray baby syndrome. |
| 2nd trimester | Contraindicated; no safe dose established; potential for serious adverse effects. |
| 3rd trimester | Contraindicated; risk of gray baby syndrome in neonate due to immature hepatic metabolism. |
Clinical note
Comprehensive clinical and safety monograph for ALDOCLOR-250 (ALDOCLOR-250).
| Placental transfer | Chloramphenicol readily crosses the placenta; fetal serum concentrations may reach 30-80% of maternal levels. |
| Breastfeeding | Chloramphenicol is excreted into breast milk; may cause bone marrow suppression and gray baby syndrome in nursing infants. Avoid breastfeeding during therapy. |
| Lactation Rating |
■ FDA Black Box Warning
None explicitly listed. However, methyldopa carries a warning for hepatotoxicity and hemolytic anemia; chlorothiazide carries a warning for electrolyte disturbances and hypersensitivity reactions.
| Serious Effects |
Hypersensitivity to chloramphenicolPregnancy (all trimesters)BreastfeedingHistory of serious hematologic toxicity with chloramphenicolHepatic impairment (in neonates)
| Precautions | Hepatotoxicity (methyldopa), hemolytic anemia, positive direct Coombs test, sedation, depression, bradycardia, orthostatic hypotension, electrolyte imbalance (hypokalemia, hyponatremia, hypomagnesemia), hyperuricemia, hyperglycemia, photosensitivity, lupus-like syndrome, and hypersensitivity reactions. |
| Food/Dietary | Avoid high-potassium foods (bananas, oranges, spinach) unless specifically advised; chlorothiazide may cause potassium loss, but methyldopa can cause potassium retention. Avoid excessive alcohol intake as it may potentiate hypotension. Take with food to reduce gastrointestinal upset. May decrease glucose tolerance; monitor in diabetic patients. |
Loading safety data…
| Avoid |
| Teratogenic Risk | FDA Pregnancy Category D. First trimester: Associated with cardiovascular defects (e.g., VSD), neural tube defects, and oral clefts. Second and third trimesters: Fetal nephrotoxicity (oligohydramnios, renal failure), premature closure of ductus arteriosus, pulmonary hypertension, and intracranial hemorrhage. Avoid in third trimester. |
| Fetal Monitoring | Monitor maternal blood pressure, serum electrolytes, renal function, and fetal growth via ultrasound. Assess amniotic fluid volume (risk of oligohydramnios). Fetal echocardiography if exposure after 20 weeks. |
| Fertility Effects | Chlorothiazide may impair erectile function and cause reversible gynecomastia in males. No direct evidence of female fertility impairment; however, electrolyte disturbances could affect ovulation. |
| Clinical Pearls | Aldoclor-250 is a combination of methyldopa (250mg) and chlorothiazide. Methyldopa can cause a positive direct Coombs test (10-20% of patients) which may interfere with blood cross-matching; obtain a hematocrit and Coombs test before therapy and at 6 and 12 months. Chlorothiazide may cause hypokalemia; monitor potassium and consider potassium supplementation. Onset of methyldopa is 3-6 hours; delay full effect for 48-72 hours. Avoid use in patients with active liver disease or history of previous methyldopa-induced liver dysfunction. |
| Patient Advice | Take exactly as prescribed; do not skip doses or stop suddenly. · May cause drowsiness or dizziness; avoid driving or operating machinery until you know how it affects you. · Rise slowly from sitting or lying to prevent lightheadedness. · Report any unexplained fever, jaundice, or dark urine immediately. · Use sun protection; this drug may increase sensitivity to sunlight. · Do not use potassium supplements or salt substitutes without consulting your doctor. · If you miss a dose, take it as soon as you remember unless it's near the next dose; do not double. |