C09CA07 - Telmisartan |
Propably not porphyrinogenic |
PNP |
Rationale
Telmisartan is not metabolized by CYP450 enzymes. Telmisartan has been found to be an inhibitor of CYP2C19 and CYP2C9 in vitro, but this has not been observed in vivo.
Chemical description
Angiotensin II receptor antagonist
Therapeutic characteristics
Telmisartan is used in the treatment of essential hypertension. It is administered orally.
Hepatic exposure
Oral administration of 40 mg telmisartan gave a Cmax of 44.7 ng/ml (Wienen 2000), which is equivalent to 87 nM.
Metabolism and pharmakokinetics
Telmisartan is metabolized by glucuronidation and no CYP450 enzymes are thought to be involved (SPC).
Telmisartan was found to be an in vitro inhibitor of CYP2C9, however such inhibition is unlikely to be clinically relevant due to the low free plasma concentration obtained at therapeutic doses (Kamiyama 2007). An in vivo study with co-administration of telmisartan and the CYP2C9 substrate, warfarin, did not demonstrate a clinically relevant drug-drug interaction (Stangier 2000).
In vitro testing showed that telmisartan inhibited CYP2C19, but this was not clinically relevant (Wienen 2000).
IPNet drug reports
Uneventful use reported in 1 patient with acute porphyria.
References
- Scientific articles
- Kamiyama E, Yoshigae Y, et al. Inhibitory effects of angiotensin receptor blockers on CYP2C9 activity in human liver microsomes. Drug Metab Pharmacokinet. 2007 Aug;22(4):267-75. #1315
- Stangier J, Su CA, et al. Steady-state pharmacodynamics and pharmacokinetics of warfarin in the presence and absence of telmisartan in healthy male volunteers. J Clin Pharmacol. 2000 Dec;40(12 Pt 1):1331-7. PMID 11185631. #4415
- Wienen W, Entzeroth M, et al. A Review on Telmisartan: A Novel, Long-Acting Angiotensin II-Receptor Antagonist. Cardiovascular Drug Reviews. 2000. Vol. 18, No. 2, pp. 127–154 #1318
- Summary of Product Characteristics
- The electronic Medicines Compendium (emc). Summary of Product Characteristics (SPC). (Micardis). #1317
Similar drugs
© NAPOS 2024