Telmisartan was patented in 1991 and came into medical use in 1999.[7] It is available as a generic medication.[8] In 2022, it was the 228th most commonly prescribed medication in the United States, with more than 1million prescriptions.[9][10] It is available in combination with hydrochlorothiazide as telmisartan/hydrochlorothiazide;[11] with cilnidipine as telmisartan/cilnidipine;[12] and with amlodipine as telmisartan/amlodipine.[6][13]
Side effects include tachycardia and bradycardia (fast or slow heartbeat), hypotension (low blood pressure) and edema (swelling of arms, legs, lips, tongue, or throat, the latter leading to breathing problems). Allergic reactions may also occur.[6]
Interactions
Due to its mechanism of action, telmisartan increases blood potassium levels. Combination with potassium preparations or potassium-sparing diuretics could cause hyperkalaemia (excessive potassium levels). Combination with NSAIDs, especially in patients with impaired kidney function, has a risk of causing (usually reversible) kidney failure.[15]
Pharmacology
Mechanism of action
Telmisartan is an angiotensin II receptor blocker that shows high affinity for the angiotensin II receptor type 1 (AT1), with a binding affinity 3000 times greater for AT1 than AT2.
In addition to blocking the renin–angiotensin system, telmisartan acts as a partial agonist of peroxisome proliferator-activated receptor gamma (PPAR-γ), a central regulator of insulin and glucose metabolism. It is believed that telmisartan's dual mode of action may provide protective benefits against the vascular and renal damage caused by diabetes and cardiovascular disease (CVD).[16][14]: 171 As a partial agonist, it activates the receptor by 25–30%. Clinical trials have shown that telmisartan increases insulin sensitivity, reduces cardiac fibrosis and hypertrophy, and improves endothilial function; all these effects can be attributed to its activity on PPAR-γ.[17] The kidney-protecting activity of telmisartan is attributed to both angiotensin II antagonism and improved endothelial function from PPAR-γ.[17]
Telmisartan's activity at the peroxisome proliferator-activated receptor delta (PPAR-δ) receptor has prompted speculation around its potential as a sport doping agent as an alternative to GW 501516.[18] Telmisartan activates PPAR-δ receptors in several tissues. In mice, this results in effects such as enhanced endurance.[19][20][21][22] However, telmisartan does not improve the walking performance (6-minute walk distance) in people with lower extremityperipheral artery disease.[23]
Telmisartan does not cause rapid cancer growth like the PPAR-δ agonist GW 501516, but whether it causes a change in cancer rates is disputed. Short-term use is not associated with an increased incidence of cancer over other ARB drugs, according to a large 2016 analysis of UK patients.[29] A 2022 meta-analysis finds that a longer duration of taking ARBs (including telmisartan) is associated with an increase in cancer rates. Patients who have taken an ARB for more than 3 years appears 11% more likely to develop cancer.[30] A 2023 large-scale study on Lebanese patients finds that taking ARBs reduces the incidence of cancer, with greater effects on those who have taken the drug for a long time. A 2021 Korean study and a 2012 Japanese study finds similar results.[31]
^Yin SN, Liu M, Jing DQ, Mu YM, Lu JM, Pan CY (2014). "Telmisartan increases lipoprotein lipase expression via peroxisome proliferator-activated receptor-alpha in HepG2 cells". Endocrine Research. 39 (2): 66–72. doi:10.3109/07435800.2013.828741. PMID24067162.
^Stangier J, Su CA, Roth W (2000). "Pharmacokinetics of orally and intravenously administered telmisartan in healthy young and elderly volunteers and in hypertensive patients". The Journal of International Medical Research. 28 (4): 149–167. doi:10.1177/147323000002800401. PMID11014323. S2CID33299699.
Yusuf S, Teo KK, Pogue J, Dyal L, Copland I, Schumacher H, et al. (April 2008). "Telmisartan, ramipril, or both in patients at high risk for vascular events". The New England Journal of Medicine. 358 (15). Massachusetts Medical Society: 1547–1559. doi:10.1056/nejmoa0801317. hdl:2437/81925. PMID18378520.
Yusuf S, Teo K, Anderson C, Pogue J, Dyal L, Copland I, et al. (September 2008). "Effects of the angiotensin-receptor blocker telmisartan on cardiovascular events in high-risk patients intolerant to angiotensin-converting enzyme inhibitors: a randomised controlled trial". Lancet. 372 (9644): 1174–1183. doi:10.1016/S0140-6736(08)61242-8. PMID18757085. S2CID5203511.