Telmisartan belongs to a class of medications known as angiotensin II receptor antagonists. These medications reduce blood pressure by blocking the actions of a chemical (angiotensin II) that causes blood vessels to constrict or tighten. It is used to treat mild-to-moderate high blood pressure.

When blood pressure is allowed to remain high for a long time, the blood vessels of the heart, kidneys, and brain may become damaged. This puts a person at increased risk for heart attack and stroke as well as kidney failure and blindness. Keeping blood pressure in the normal range can reduce the risk for these conditions.

Telmisartan is also used to reduce the risk of death caused by a heart attack or stroke, for people who cannot use another type of medication called angiotensin-converting enzyme inhibitor.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended adult dose of telmisartan is 80 mg once a day at approximately the same time each day. It may be taken with or without food, but it should be taken the same way each time. Tablets should be swallowed whole with water.

It will take about 2 weeks for reductions in blood pressure to become noticeable and another 2 weeks until the full effects of the medication are realized. People with reduced liver function are usually given 40 mg once daily to start.

It is important to take this medication regularly and to follow your doctor's instructions regarding blood pressure monitoring to ensure that you are getting the maximum benefit from the medication.

If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Store telmisartan at normal room temperature in a dry place (not in the bathroom) and keep it out of the reach of children. Do not remove tablets from their blister-pack until you are ready to take them.

40 mg
Each white or off-white, oblong, biconvex, uncoated tablet, debossed with "TEL40" on one side and plain on the other, contains 40 mg of telmisartan. Nonmedicinal ingredients:  mannitol, meglumine, povidone, sodium hydroxide, and sodium stearyl fumarate.

80 mg
Each white or off-white, oval, biconvex, uncoated tablet, debossed with "TEL80" on one side and plain on the other, contains 80 mg of telmisartan. Nonmedicinal ingredients:  mannitol, meglumine, povidone, sodium hydroxide, and sodium stearyl fumarate.

Do not take telmisartan if you:

• are allergic to telmisartan or to any of the ingredients of the medication
• are pregnant or plan to become pregnant
• are breast-feeding
• have diabetes or kidney disease and are taking the medication aliskiren
• are allergic to certain sugars (fructose and/or sorbitol intolerant)

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• anxiety
• back or leg pain
• constipation
• diarrhea
• difficulty sleeping
• drowsiness
• dry mouth
• eczema or skin rash
• gas
• headache
• joint pain
• muscle cramps or spasms
• nausea
• rash
• tiredness
• upper respiratory tract infection (such as colds or sinus infections)
• upset stomach
• vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• chest pain
• dizziness, fainting, or lightheadedness
• symptoms of low blood sugar (e.g., cold sweat, cool pale skin, headache, fast heartbeat, weakness)
• shortness of breath
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don’t stop bleeding)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of kidney problems (e.g., decreased urination, nausea, vomiting, swelling of the feet and ankles)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of too much potassium in the body (e.g., irregular heartbeat, muscle weakness, generally feeling unwell)
• symptoms of low sodium levels in the blood (e.g., achy, stiff or uncoordinated muscles, confusion, tiredness, weakness)
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)
• unexplained muscle pain, tenderness, or weakness
• vision changes

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious blood infection (e.g., chills, confusion, fever or low body temperature, shakiness, irregular heartbeat)
• signs of a serious allergic reaction (e.g., swelling of face, lips, tongue, or throat; hives; difficulty breathing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Drowsiness/reduced alertness: Telmisartan may cause drowsiness or dizziness, affecting your ability to drive or operate machinery. Avoid these and other hazardous tasks until you have determined how this medication affects you.

Kidney disease: Telmisartan may affect kidney function, especially for people who already have kidney problems. Taking this medication along with the medication aliskiren or an angiotensin-converting enzyme inhibitor (ACEI) further increases the risk of kidney problems. If you have reduced kidney function or kidney disease, renal artery stenosis (narrowing of blood vessels in the kidneys), or congestive heart failure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of decreased kidney function, such as puffy hands, face or feet, high blood pressure, unusual muscle cramping, or darkened urine, contact your doctor as soon as possible.

Liver disease: Telmisartan is removed from the body by the liver. On rare occasions, it may cause liver problems. If you have liver disease or decreased liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Low blood pressure: If you have orthostatic hypotension (a sudden drop in blood pressure caused by standing up, which may lead to fainting), you should be cautious while taking telmisartan, as it can worsen the condition. The first time this medication is taken, it may cause dizziness, lightheadedness, or fainting. This may be reduced by taking the medication in a sitting position and being careful to rise slowly to a standing position. The dizziness usually improves after the first dose, but if the medication is stopped and then started again, it may reappear. Your doctor may also adjust the dose.

Severe, sudden decreases in blood pressure can reduce the blood flow to muscles and organs in the body. These blood pressure drops can contribute to strokes or heart attacks. If you experience frequent occurrences of decreased blood pressure, talk to your doctor.

Potassium levels: This medication may affect potassium levels in the blood, especially when used for heart failure, or when taken with other medications called ACE inhibitors, aliskiren, or diuretics such as spironolactone. Your doctor will monitor your potassium levels while on this medication. Avoid using salt substitutes that contain potassium while you are taking telmisartan.

Pregnancy: Telmisartan may cause severe harm to an unborn fetus and should not be taken during pregnancy. If you discover you are pregnant while taking this medication, stop taking the medication and tell your doctor at once.

Breast-feeding: It is not known if telmisartan passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between telmisartan and any of the following:

• aldesleukin
• aldosterone antagonists (e.g., eplerenone, finerenone, spironolactone)
• aliskiren
• alpha-blockers (e.g., alfuzosin, doxazosin, silodosin, tamsulosin)
• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• angiotensin-converting enzyme inhibitors (ACEIs; captopril, enalapril, ramipril)
• other angiotensin receptor blockers (ARBs; e.g., candesartan, irbesartan, losartan)
• antipsychotics (e.g., cariprazine, clozapine, olanzapine, quetiapine, risperidone)
• apomorphine
• barbiturates (e.g., butalbital, phenobarbital)
• brigatinib
• brimonidine
• bortezomib
• bromocriptine
• diazoxide
• digoxin
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
• drospirenone
• duloxetine
• flunarizine
• general anesthetics (medications used to put people to sleep before surgery)
• heparin
• levodopa
• lithium
• low molecular weight heparins (e.g., dalteparin, enoxaparin, tinzaparin)
• methylphenidate
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• morphine
• nabilone
• nitrates (e.g., isosorbide dinitrate, nitroglycerin)
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., celecoxib, naproxen, ibuprofen)
• obinutuzumab
• pentoxifylline
• pergolide
• phosphodiesterase 5 inhibitors (e.g., sildenafil, tadalafil, vardenafil)
• potassium supplements or medications that increase potassium in the blood
• pramipexole
• primidone
• ranolazine
• riociguat
• ropinirole
• rotigotine
• sacubitril
• sodium phosphates
• sotalol
• tacrolimus
• tizanidine
• tolvaptan
• tretinoin
• tricyclic antidepressants (e.g., clomipramine, imipramine)
• trimethoprim
• yohimbine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.