Valsartan vs Telmisartan
## Overview
Telmisartan has the longest half-life of any ARB (~24 h) and has partial PPAR-gamma agonist activity, providing potential metabolic benefits. Valsartan has strong heart failure and post-MI evidence. Telmisartan is notable for the ONTARGET/TRANSCEND trials.
## Mechanism of Action
Both block AT1. Telmisartan additionally activates PPAR-gamma (peroxisome proliferator-activated receptor gamma), with potential effects on insulin sensitivity and adiponectin levels. This is a unique property among ARBs.
## Pharmacokinetics
Telmisartan: half-life ~24 h (longest of any ARB), bioavailability ~42–58%, almost entirely eliminated in feces (>97%), no renal excretion — making it safe in CKD without dose adjustment. Valsartan: half-life ~6 h, 83% fecal.
## Clinical Evidence
ONTARGET compared telmisartan vs. ramipril vs. combination in high-risk patients (similar to HOPE), showing telmisartan non-inferior to ramipril. TRANSCEND showed telmisartan beneficial in ACEi-intolerant high-risk patients. Valsartan has VALIANT (post-MI) and Val-HeFT (HF) data.
## Key Takeaways
- Telmisartan: longest half-life (24 h), entirely fecal excretion (safe in CKD), PPAR-gamma agonist
- Valsartan: stronger HF data; requires more frequent dosing consideration
- Telmisartan: preferred in CKD, diabetic patients, once-daily adherence concern
บทสรุป
Telmisartan is preferred in patients with CKD (entirely fecal elimination) and as once-daily therapy for adherence-challenged patients. Valsartan is preferred in heart failure (Val-HeFT, VALIANT data). For hypertension without HF or renal impairment, both are comparable.