Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
TECZEM vs ALDORIL 15
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Enalapril inhibits angiotensin-converting enzyme (ACE), reducing angiotensin II formation, leading to vasodilation and decreased aldosterone secretion. Diltiazem inhibits calcium ion influx across cardiac and smooth muscle cells, causing coronary vasodilation and decreased myocardial contractility.
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.
Hypertension,Stable angina,Chronic stable angina
Hypertension
1 to 2 tablets (enalapril 5 mg/diltiazem 180 mg) orally once daily. Maximum: 2 tablets daily.
1 tablet (hydrochlorothiazide 15 mg, methyldopa 250 mg) orally twice daily; increase as needed up to 2 tablets twice daily.
Terminal elimination half-life: 3-4 hours for diltiazem; clinical context: requires twice-daily dosing due to short half-life.
Terminal half-life: 12–17 hours; clinical context: steady-state achieved within 2–3 days; effect persists 12–24 hours
Enalapril is hydrolyzed to active enalaprilat, mainly hepatically. Diltiazem is extensively metabolized in the liver via CYP3A4.
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.
Renal: 40-50% unchanged; hepatic/biliary/fecal: 50-60% as metabolites.
Renal: ~70% unchanged; biliary/fecal: ~30% as metabolites
70-80% bound to albumin and alpha-1-acid glycoprotein.
~90%, primarily to albumin
5-7 L/kg; indicates extensive tissue distribution.
2–4 L/kg; clinical meaning: extensive tissue distribution, concentrating in vascular smooth muscle
Oral: 35-60% due to first-pass metabolism; IV: 100%.
Oral: 50–60% (extensive first-pass metabolism)
GFR >30 m L/min: No adjustment. GFR 10-30 m L/min: Use with caution, monitor potassium and creatinine. GFR <10 m L/min: Avoid use.
GFR 30-50 m L/min: maximum 1 tablet twice daily. GFR <30 m L/min: avoid use.
Child-Pugh A: No adjustment. Child-Pugh B: Use with caution, consider starting at lowest dose. Child-Pugh C: Contraindicated.
Child-Pugh A: caution, reduce dose. Child-Pugh B: avoid. Child-Pugh C: contraindicated.
Safety and efficacy not established for patients <18 years.
Not recommended for pediatric use; safety in children under 12 years not established.
Start at lowest dose, monitor renal function and electrolytes due to age-related decreased renal function and increased sensitivity.
Start with 1 tablet once daily; monitor for hypotension and electrolyte imbalance. Reduce initial dose by 50%.
Use in pregnancy: ACE inhibitors can cause injury and death to the developing fetus. Discontinue as soon as possible when pregnancy is detected.
None
Hypotension,Angioedema,Hepatic injury,Heart block,Bradycardia,Renal impairment,Hyperkalemia
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.
Hypersensitivity to enalapril, diltiazem, or any component,History of angioedema related to ACE inhibitors,Second- or third-degree AV block (except with pacemaker),Sick sinus syndrome,Severe hypotension,Cardiogenic shock,Concurrent use with riociguat
Active hepatic disease (e.g., acute hepatitis, cirrhosis),Prior methyldopa therapy associated with liver disorders,Hypersensitivity to methyldopa or hydrochlorothiazide,Anuria,Sulfonamide allergy (cross-sensitivity with thiazides)
Avoid high-potassium foods (e.g., bananas, oranges, spinach) due to potential for hyperkalemia from enalapril. Grapefruit juice may increase diltiazem levels and should be limited or avoided. Alcohol can exacerbate hypotension.
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.
TECZEM (enalapril maleate and felodipine) is contraindicated in pregnancy. ACE inhibitors can cause fetal and neonatal morbidity and death when administered to pregnant women. First trimester exposure may be associated with a small increased risk of congenital anomalies; second and third trimester exposure is associated with oligohydramnios, fetal renal dysfunction, skull ossification defects, and neonatal hypotension, anuria, and renal failure. Felodipine: No teratogenic effects in animal studies at clinically relevant doses; however, limited human data. Combined use should be avoided in pregnancy.
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.
Enalapril is excreted in human milk in trace amounts; the M/P ratio is approximately 0.01. Felodipine is excreted in human milk; the M/P ratio is unknown. Due to potential for adverse effects in the nursing infant, especially renal effects from enalapril, breastfeeding is not recommended during TECZEM therapy.
Methyldopa and hydrochlorothiazide are excreted into human milk. M/P ratio for methyldopa is approximately 0.5-1.0; for hydrochlorothiazide, M/P ratio ~2.0. Methyldopa is considered compatible with breastfeeding. Hydrochlorothiazide may suppress lactation and cause neonatal electrolyte disturbances. Use with caution; monitor infant for signs of diuresis or electrolyte imbalance.
TECZEM is contraindicated in pregnancy. If a woman becomes pregnant while on TECZEM, discontinue the drug immediately. No dose adjustments are recommended as the drug should not be used. Alternative antihypertensive therapy should be considered if needed.
Pharmacokinetic changes in pregnancy may include increased volume of distribution and enhanced renal clearance. No specific dose adjustment routine is recommended; dosing should be guided by clinical response. Methyldopa starting dose 250 mg twice daily, titrated to effect. Hydrochlorothiazide dose not typically adjusted, but caution due to potential volume depletion.
TECZEM (enalapril/diltiazem ER) combines an ACE inhibitor and a non-dihydropyridine calcium channel blocker. Monitor renal function and serum potassium; avoid in patients with pre-existing high-grade AV block or severe left ventricular dysfunction. Use with caution in patients with hepatic impairment due to diltiazem metabolism. May cause reflex tachycardia less frequently than dihydropyridines.
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.
Take this medication exactly as prescribed; do not crush or chew the extended-release tablet.,Monitor blood pressure regularly and report symptoms such as dizziness, fainting, or irregular heartbeat.,Avoid salt substitutes containing potassium unless directed by your doctor.,Report any signs of angioedema (swelling of face, lips, tongue, or difficulty breathing) immediately.
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.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about TECZEM vs ALDORIL 15, answered by our medical review team.
TECZEM is a Antihypertensive combination that works by Enalapril inhibits angiotensin-converting enzyme (ACE), reducing angiotensin II formation, leading to vasodilation and decreased aldosterone secretion. Diltiazem inhibits calcium ion influx across cardiac and smooth muscle cells, causing coronary vasodilation and decreased myocardial contractility.. ALDORIL 15 is a Antihypertensive Combination that works by 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.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between TECZEM and ALDORIL 15 depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of TECZEM is: 1 to 2 tablets (enalapril 5 mg/diltiazem 180 mg) orally once daily. Maximum: 2 tablets daily.. The standard adult dose of ALDORIL 15 is: 1 tablet (hydrochlorothiazide 15 mg, methyldopa 250 mg) orally twice daily; increase as needed up to 2 tablets twice daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between TECZEM and ALDORIL 15 in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. TECZEM is classified as Category C. TECZEM (enalapril maleate and felodipine) is contraindicated in pregnancy. ACE inhibitors can cause fetal and neonatal morbidity and death when administered to pregnant women. Firs. ALDORIL 15 is classified as Category C. 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: . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.