Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
TECZEM vs ALDORIL 25
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.
Combination of methyldopa, a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow, and hydrochlorothiazide, a thiazide diuretic that inhibits sodium reabsorption in the distal convoluted tubule, reducing plasma volume.
Hypertension,Stable angina,Chronic stable angina
Hypertension
1 to 2 tablets (enalapril 5 mg/diltiazem 180 mg) orally once daily. Maximum: 2 tablets daily.
Oral: 1 tablet (hydrochlorothiazide 25 mg/methyldopa 250 mg) twice daily; increase as needed to max 2 tablets twice daily.
Terminal elimination half-life: 3-4 hours for diltiazem; clinical context: requires twice-daily dosing due to short half-life.
7-16 hours (terminal). In renal impairment, half-life may exceed 24 hours, requiring dose adjustment.
Enalapril is hydrolyzed to active enalaprilat, mainly hepatically. Diltiazem is extensively metabolized in the liver via CYP3A4.
Methyldopa is metabolized primarily via hepatic conjugation and renal excretion; hydrochlorothiazide is not significantly metabolized and is excreted unchanged in urine.
Renal: 40-50% unchanged; hepatic/biliary/fecal: 50-60% as metabolites.
Renal: ~85% unchanged. Biliary/fecal: ~15% as metabolites.
70-80% bound to albumin and alpha-1-acid glycoprotein.
Methyldopa: less than 10% bound to plasma proteins. Hydrochlorothiazide: ~70% bound to plasma proteins (primarily albumin).
5-7 L/kg; indicates extensive tissue distribution.
Methyldopa: 0.3-0.6 L/kg (distributes widely, including CNS). Hydrochlorothiazide: 0.8-1.5 L/kg (distributes into extracellular fluid).
Oral: 35-60% due to first-pass metabolism; IV: 100%.
Methyldopa: oral bioavailability ~25% (first-pass metabolism). Hydrochlorothiazide: oral bioavailability ~60-80%.
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: use with caution, reduce dose. GFR <30 m L/min: not recommended.
Child-Pugh A: No adjustment. Child-Pugh B: Use with caution, consider starting at lowest dose. Child-Pugh C: Contraindicated.
Child-Pugh A: no adjustment; Child-Pugh B or C: contraindicated due to methyldopa hepatotoxicity risk.
Safety and efficacy not established for patients <18 years.
Not established; avoid use in children.
Start at lowest dose, monitor renal function and electrolytes due to age-related decreased renal function and increased sensitivity.
Start at lowest dose (1 tablet daily); monitor for orthostatic hypotension, sedation, and electrolyte imbalance.
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
May cause sedation, depression, positive direct Coombs test, hemolytic anemia, hepatotoxicity, fluid/electrolyte imbalance, and sensitivity reactions; monitor liver function, CBC, and electrolytes.
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
Hypersensitivity to methyldopa, hydrochlorothiazide, or sulfonamides; active hepatic disease; anuria; history of methyldopa-induced liver disorders.
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 to optimize antihypertensive effect. Limit alcohol intake. Do not consume large amounts of potassium-rich foods (e.g., bananas, oranges, spinach) unless advised by a healthcare provider, as hydrochlorothiazide can alter potassium levels.
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: Limited human data, but animal studies show no teratogenicity at therapeutic doses. Second and third trimesters: Associated with fetal hypotension, oligohydramnios, and renal dysfunction due to methyldopa component. Hydrochlorothiazide may cause fetal electrolyte imbalances.
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 is excreted in breast milk with M/P ratio of approximately 0.2-0.5; hydrochlorothiazide M/P ratio ~0.5-0.6. Considered compatible with breastfeeding by AAP, but monitor infant for hypotension and electrolyte disturbances.
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.
No standard dose adjustment required, but increased plasma volume in pregnancy may necessitate higher doses of methyldopa. Monitor clinical response and adjust accordingly.
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 25 is a fixed-dose combination of methyldopa (250 mg) and hydrochlorothiazide (25 mg). Monitor for hypotension, especially during initial therapy or with volume depletion. Methyldopa may cause a positive direct Coombs test and hemolytic anemia; discontinue if anemia develops. Hydrochlorothiazide can cause electrolyte imbalances, hyperglycemia, and hyperuricemia. Avoid use in patients with pheochromocytoma or active liver disease.
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.
Take this medication exactly as prescribed, usually once or twice daily.,Rise slowly from sitting or lying to prevent dizziness from low blood pressure.,Avoid alcohol, which can increase dizziness and drowsiness.,Report any signs of infection, unusual tiredness, or yellowing of skin/eyes.,Use sun protection as hydrochlorothiazide may increase sun sensitivity.,Do not use potassium supplements or salt substitutes without consulting your doctor.
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 25, 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 25 is a Antihypertensive Combination that works by Combination of methyldopa, a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow, and hydrochlorothiazide, a thiazide diuretic that inhibits sodium reabsorption in the distal convoluted tubule, reducing plasma volume.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between TECZEM and ALDORIL 25 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 25 is: Oral: 1 tablet (hydrochlorothiazide 25 mg/methyldopa 250 mg) twice daily; increase as needed to max 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 25 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 25 is classified as Category C. First trimester: Limited human data, but animal studies show no teratogenicity at therapeutic doses. Second and third trimesters: Associated with fetal hypotension, oligohydramnios. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.