Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
KATERZIA vs ADALAT
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
KATERZIA (bosentan) is an endothelin receptor antagonist (ERA) that blocks endothelin-1 (ET-1) from binding to ETA and ETB receptors in the endothelium and vascular smooth muscle. This inhibits ET-1-mediated vasoconstriction and smooth muscle proliferation, reducing pulmonary vascular resistance and pulmonary arterial pressure.
Dihydropyridine calcium channel blocker; inhibits calcium ion influx across cardiac and vascular smooth muscle cells, reducing peripheral vascular resistance and blood pressure.
Treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) to improve exercise ability and decrease clinical worsening in patients with WHO class II–IV symptoms,Off-label: Treatment of digital ulcers in systemic sclerosis; prevention of recurrence of digital ulcers; management of inoperable chronic thromboembolic pulmonary hypertension
Hypertension,Chronic stable angina,Vasospastic angina (Prinzmetal's angina)
5 mg orally once daily for 21 days, then 7 days off, repeated in 28-day cycles.
10-20 mg orally three times daily; extended-release: 30-60 mg orally once daily; maximum 120 mg/day.
Terminal elimination half-life is approximately 9-12 hours in healthy adults. In patients with hypertension or hepatic impairment, half-life may be prolonged up to 15-20 hours, necessitating dose adjustment.
Terminal elimination half-life: 2-5 hours (immediate-release); 8-14 hours (extended-release). Context: shorter half-life necessitates multiple daily dosing for immediate-release; extended-release allows once-daily dosing.
Primarily metabolized by CYP2C9 and CYP3A4 to three major metabolites (Ro 48-5033, Ro 47-8634, Ro 64-1056). Induces CYP2C9 and CYP3A4; also induces CYP2C19.
Hepatic via CYP3A4; extensive first-pass metabolism; metabolites are inactive.
Renal elimination accounts for approximately 60-80% of the administered dose, predominantly as unchanged drug via glomerular filtration and active tubular secretion. Biliary/fecal excretion is minimal, <5%.
Renal: 70-80% as metabolites; Fecal: 15-20% as metabolites; <1% unchanged in urine
Approximately 95-98% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein. High binding limits tissue distribution and affects free drug concentration.
92-98% bound to plasma proteins (albumin and alpha-1-acid glycoprotein)
Volume of distribution is approximately 0.7-1.2 L/kg (range 50-80 L for a 70 kg adult), indicating moderate tissue distribution beyond plasma volume.
0.8-1.2 L/kg. Clinical meaning: indicates extensive tissue distribution, consistent with high lipophilicity.
Oral bioavailability is approximately 30-40% due to extensive first-pass hepatic metabolism. Food may reduce bioavailability by 20-30%, so dosing should be consistent with respect to meals.
Oral immediate-release: 45-60% (due to first-pass metabolism); extended-release: 60-85% (due to slower release and reduced first-pass effect).
No dose adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). Not recommended in severe renal impairment (Cr Cl <30 m L/min) or end-stage renal disease.
No dose adjustment required for GFR ≥30 m L/min; for GFR <30 m L/min, use with caution and reduce initial dose by 50%.
Child-Pugh A: No adjustment. Child-Pugh B: Reduce dose to 5 mg orally once daily for 21 days, then 7 days off. Child-Pugh C: Not recommended.
Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid use or reduce by 75%.
Safety and efficacy not established in pediatric patients.
0.25-0.5 mg/kg/dose orally every 6-8 hours; maximum 3 mg/kg/day. Extended-release not recommended.
No specific dose adjustment required; monitor for adverse events due to potential age-related renal and hepatic decline.
Start at 10 mg orally twice daily; titrate slowly due to increased sensitivity and risk of hypotension.
WARNING: HEPATOTOXICITY. Bosentan can cause serious hepatic injury, including acute liver failure, requiring baseline and monthly monitoring of liver enzymes. Discontinue if ALT/AST >3x ULN accompanied by symptoms or bilirubin >2x ULN.
None
Hepatotoxicity (monitor LFTs monthly), hepatorenal syndrome; peripheral edema; fluid retention; may cause hypotension; pulmonary veno-occlusive disease (PVOD) may cause pulmonary edema; decreases hemoglobin and hematocrit (monitor at 1 and 3 months, then every 3 months); decreases sperm count; reduces efficacy of hormonal contraceptives (use alternative contraception); caution in hepatic impairment (Child-Pugh Class A; contraindicated in moderate to severe impairment); caution in elderly; not recommended in patients with severe anemia.
May cause hypotension, especially in patients on beta-blockers or with poor cardiac reserve,Risk of increased angina and/or myocardial infarction upon initiation or dose increase,Peripheral edema,Stevens-Johnson syndrome and toxic epidermal necrolysis (rare),Hepatic impairment,Exacerbation of angina on withdrawal
Absolute: Hypersensitivity to bosentan or any component; moderate to severe hepatic impairment (Child-Pugh Class B or C); baseline AST/ALT >3× ULN; concomitant use with cyclosporine A (increases bosentan levels and hepatotoxicity); concomitant use with glyburide (increases risk of liver enzyme elevations); pregnancy (teratogenic in animals – can cause birth defects; must exclude pregnancy before initiation and monthly thereafter).
Hypersensitivity to nifedipine,Cardiogenic shock,Significant aortic stenosis,Concurrent use with rifampin,Pregnancy (category C)
Take with food to improve tolerability and reduce gastrointestinal adverse effects. Avoid grapefruit juice as it may increase treprostinil exposure. Avoid alcohol as it may exacerbate vasodilation and hypotension.
Avoid grapefruit and grapefruit juice; they inhibit CYP3A4 and increase nifedipine serum concentrations, leading to enhanced hypotensive effects and risk of toxicity. Grapefruit interaction persists for 24 hours; separate consumption by at least 4 hours if unavoidable, but preferable to avoid entirely. Avoid alcohol which can increase hypotension. High-fat meals may reduce absorption of extended-release formulations; take consistently with or without food.
Pregnancy Category C. First trimester: animal studies show fetal toxicity; no adequate human data. Second/third trimester: may cause fetal renal impairment, oligohydramnios, and skull ossification defects due to direct renin-angiotensin system inhibition.
First trimester: Limited human data; animal studies show embryotoxicity. Second/third trimester: May cause fetal hypoxia due to maternal hypotension; risk of preterm labor inhibition. Category C.
No human data; M/P ratio unknown. Excreted in rat milk. Due to potential risk of hypotension and renal impairment in nursing infants, discontinue drug or breastfeeding, considering importance to mother.
Excreted in breast milk; M/P ratio ~0.85. Consider risks versus benefits; monitor infant for hypotension.
No specific dose adjustments established for pregnancy. However, due to increased plasma volume, efficacy may be reduced; monitor therapeutic response. Contraindicated in pregnancy; avoid use.
No standard dose adjustment; monitor clinical response and blood pressure; may require lower doses due to vasodilation effects.
KATERZIA (oral treprostinil) is a prostacyclin analogue used for pulmonary arterial hypertension (PAH). Monitor for prostacyclin-related side effects (headache, nausea, diarrhea, jaw pain, flushing). Dose titration is critical; increase by 0.25 mg BID or 0.125 mg TID every 3-4 days as tolerated. Avoid abrupt discontinuation due to risk of rebound pulmonary hypertension. Use with caution in patients with hepatic impairment; reduce starting dose in moderate impairment.
Adalat (nifedipine) is a dihydropyridine calcium channel blocker. Use immediate-release capsules only for hypertensive emergencies, not chronic treatment due to risk of reflex tachycardia and unpredictable hypotension. Extended-release formulations are preferred for stable angina and hypertension. Avoid grapefruit juice as it increases nifedipine levels via CYP3A4 inhibition. Monitor for peripheral edema, gingival hyperplasia, and constipation. Contraindicated in cardiogenic shock, severe aortic stenosis, and within 4 weeks of myocardial infarction.
Take KATERZIA exactly as prescribed, with food to reduce gastrointestinal side effects.,Do not stop taking this medication suddenly; consult your doctor before making any changes.,Common side effects include headache, nausea, diarrhea, jaw pain, and flushing; report severe or persistent symptoms.,Avoid alcohol and grapefruit juice as they may interact with the medication.,Store tablets in the original container at room temperature, away from moisture and light.,If you miss a dose, skip it and take the next dose at the scheduled time; do not double dose.,Inform your healthcare provider of all medications you are taking, especially antihypertensives, anticoagulants, and NSAIDs.
Swallow extended-release tablets whole; do not crush, chew, or split.,Avoid grapefruit and grapefruit juice while taking this medication.,Report persistent swelling of ankles/feet, gum tenderness or bleeding, or severe dizziness.,Do not stop abruptly; taper under medical supervision to avoid rebound hypertension.,Take at the same time each day; if a dose is missed, skip it if near next dose.,May cause dizziness; avoid driving until you know how it affects you.,Increase fluid and fiber intake to prevent constipation.,Store at room temperature away from light and moisture.
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 KATERZIA vs ADALAT, answered by our medical review team.
KATERZIA is a Calcium Channel Blocker that works by KATERZIA (bosentan) is an endothelin receptor antagonist (ERA) that blocks endothelin-1 (ET-1) from binding to ETA and ETB receptors in the endothelium and vascular smooth muscle. This inhibits ET-1-mediated vasoconstriction and smooth muscle proliferation, reducing pulmonary vascular resistance and pulmonary arterial pressure.. ADALAT is a Calcium Channel Blocker that works by Dihydropyridine calcium channel blocker; inhibits calcium ion influx across cardiac and vascular smooth muscle cells, reducing peripheral vascular resistance and blood pressure.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between KATERZIA and ADALAT depend on the specific clinical indication. These are both Calcium Channel Blocker agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of KATERZIA is: 5 mg orally once daily for 21 days, then 7 days off, repeated in 28-day cycles.. The standard adult dose of ADALAT is: 10-20 mg orally three times daily; extended-release: 30-60 mg orally once daily; maximum 120 mg/day.. 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 KATERZIA and ADALAT 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. KATERZIA is classified as Category C. Pregnancy Category C. First trimester: animal studies show fetal toxicity; no adequate human data. Second/third trimester: may cause fetal renal impairment, oligohydramnios, and sk. ADALAT is classified as Category C. First trimester: Limited human data; animal studies show embryotoxicity. Second/third trimester: May cause fetal hypoxia due to maternal hypotension; risk of preterm labor inhibiti. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.