Telmisartan tablets are angiotensin II receptor blockers (ARB) indicated for the treatment of hypertension to lower blood pressure. These tablets are also indicated for risk reduction of myocardial infarction, stroke, or death from cardiovascular (CV) causes in patients' ≥55 years of age at high risk of developing major CV events that are unable to take ACE inhibitors. Telmisartan blocks the angiotensin receptor. By blocking the action of angiotensin, telmisartan widens blood vessels (vasodilate) and reduces blood pressure.
Indications and Usage
- To treat high blood pressure
- To reduce the risk of non-fatal heart attack or non-fatal stroke
Telmisartan is a member of a family of drugs called angiotensin receptor blockers (ARBs). Angiotensin, formed in the blood by the action of angiotensin converting enzyme (ACE), is a powerful chemical that attaches to angiotensin receptors found in many tissues but primarily on muscle cells of blood vessels. Angiotensin's attachment to the receptors causes muscle cells to shorten and narrow the blood vessels (vasoconstrict), which leads to an increase in blood pressure (hypertension). Telmisartan blocks the angiotensin receptor. By blocking the action of angiotensin, telmisartan widens blood vessels (vasodilate) and reduces blood pressure.
High blood pressure is a common condition and when not treated, can cause damage to the brain, heart, blood vessels, kidneys and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.
Mechanism of Action
● Angiotensin II is the principal pressor agent of the renin-angiotensin system, with effects that include vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium.
● Telmisartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues, such as vascular smooth muscle and the adrenal gland. Its action is therefore independent of the pathways for angiotensin II synthesis
● There is also an AT2 receptor found in many tissues, but AT2 is not known to be associated with cardiovascular homeostasis. Telmisartan has much greater affinity (>3000-fold) for the AT1 receptor than for the AT2 receptor
● Telmisartan does not bind to or block other hormone receptors or ion channels known to be important in cardiovascular regulation
● Blockade of the angiotensin II receptor inhibits the negative regulatory feedback of angiotensin II on renin secretion, but the resulting increased plasma renin activity and angiotensin II circulating levels do not overcome the effect of telmisartan on blood pressure.
The small reduction in AUC is not expected to cause a reduction in the therapeutic efficacy. There is no linear relationship between doses and plasma levels. Cmax and to a lesser extent AUC increase disproportionately at doses above 40 mg.
Distribution: Telmisartan is largely bound to plasma protein (>99.5 %), mainly albumin and alpha-1 acid glycoprotein. The mean steady state apparent volume of distribution (Vdss) is approximately 500 l.
Biotransformation: Telmisartan is metabolised by conjugation to the glucuronide of the parent compound. No pharmacological activity has been shown for the conjugate.
Elimination: Telmisartan is characterised by biexponential decay pharmacokinetics with a terminal elimination half-life of >20 hours. The maximum plasma concentration (Cmax) and, to a smaller extent, the area under the plasma concentration-time curve (AUC), increase disproportionately with dose.
After oral administration telmisartan is nearly exclusively excreted with the faeces, mainly as unchanged compound. Cumulative urinary excretion is <1 % of dose. Total plasma clearance (Cltot) is high (approximately 1,000 ml/min) compared with hepatic blood flow (about 1,500 ml/min).
Back or leg pain, muscle cramps, joint pain, muscle spasms headache, anxiety diarrhea, constipation, nausea, vomiting, upset stomach, abdominal pain, flatulence dry mouth rash, eczema, skin eruptions drowsiness, insomnia, fatigue visual disturbances upper respiratory infection.
If any of these affects you severely, tell your doctor or pharmacist.
● Are allergic to telmisartan or to any non-medicinal ingredient in the formulation.
● Have experienced an allergic reaction with swelling of the face, lips, tongue, throat, or sudden difficulty breathing or swallowing to any ARB. Be sure to tell your doctor or pharmacist that this happened to you.
● Are pregnant or intend to become pregnant. Taking telmisartan during pregnancy can cause injury and even death to your baby.
● Are breastfeeding. It is possible that this medicine passes into breast milk.
● Are allergic to some sugars (fructose and/or sorbitol intolerant).
● Are already taking a blood pressure-lowering medicine that contains aliskiren and you having diabetes or kidney disease.
Fertility, Pregnancy And Lactation
The use of angiotensin II receptor antagonists is not recommended during the first trimester of pregnancy .The use of angiotensin II receptor antagonists is contraindicated during the second and third trimesters of pregnancy.
Here are no adequate data from the use of Telmisartan in pregnant women. Studies in animals have shown reproductive toxicity.
When pregnancy is diagnosed, treatment with angiotensin II receptor antagonists should be stopped immediately, and, if appropriate, alternative therapy should be started.
Exposure to angiotensin II receptor antagonist therapy during the second and third trimesters is known to induce human fetotoxicity (decreased renal function, oligohydramnios, skull ossification retardation) and neonatal toxicity (renal failure, hypotension, and hyperkalaemia).
Because no information is available regarding the use of Telmisartan during breast-feeding, Telmisartan is not recommended and alternative treatments with better established safety profiles during breast-feeding are preferable, especially while nursing a newborn or preterm infant.
In preclinical studies, no effects of Telmisartan on male and female fertility were observed.
Effects On Ability Drive And Use Machines
● Blood pressure lowering drugs, including diuretics ("water pills"), aliskiren-containing products (e.g. Rasilez), or angiotension-converting-enzyme inhibitors (ACEI).
● Lithium, used to treat mood disorder.
● Nonsteroidal anti-inflammatory drugs (NSAIDs) used to reduce pain and swelling. Examples include acetylsalicylic acid (ASA), celecoxib, naproxen and ibuprofen.
● Digoxin to treat many heart conditions.
● Warfarin, used to prevent blood clots (blood thinner).
● Have experienced an allergic reaction to any drug used to lower blood pressure.
● Have narrowing of a heart valve, diabetes, liver or kidney disease, heart or blood vessel disease.
● Are dehydrated or if you suffer from excessive vomiting, diarrhea, or sweating.
● Are taking a medicine that contains aliskiren, used to lower high blood pressure. The combination with telmisartan is not recommended.
● Are taking an angiotensin-converting-enzyme inhibitor (ACEI).
● Are taking a salt substitute that contains potassium, potassium supplements, or a potassium-sparing diuretic (a specific kind of "water pill" that makes your body keep potassium).
● Are on a low salt diet.
● Are on dialysis.
● Are less than 18 years old.
● Have been told by your doctor that you have intolerance to some sugars.
Proper use Of this Medication
Do not stop taking your medication before informing your doctor or pharmacist.
Overdose: If you think you have taken too much telmisartan contact your doctor, nurse, pharmacist, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.
Missed dose: If you have forgotten to take your dose during the day, carry on with the next one at the usual time. Do not double dose.