Short answer: The telmisartan label names back pain, sinusitis and diarrhea as the most common side effects in blood pressure trials. Against placebo, upper respiratory infection was 7% vs 6%, back pain 3% vs 1%, sinusitis and diarrhea 3% vs 2% each. Fewer people stopped telmisartan for side effects than stopped placebo (2.8% vs 6.1%). It carries a boxed warning for harm to an unborn baby.
What Telmisartan Tablets is approved for: Telmisartan tablets are an angiotensin II receptor blocker (ARB) approved to treat high blood pressure, alone or with other blood pressure medicines. The label says lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, mainly strokes and heart attacks (section 1.1). Telmisartan is the medicine in Micardis. Brand-name Micardis tablets are discontinued (Drugs@FDA, NDA 020850) and DailyMed has no current Micardis label, so this page uses Alembic's generic telmisartan tablets label.
Source
Telmisartan tablets, for oral use, prescribing information and Patient Information. Alembic Pharmaceuticals. DailyMed, version published June 12, 2026. DailyMed setid 4be6575f-ea8d-4cd8-a49d-3d1c93f2621a
WARNING: FETAL TOXICITY
When pregnancy is detected, discontinue telmisartan as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus (Boxed Warning; sections 5.1 and 8.1).
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Telmisartan Tablets.
| Adverse event | Telmisartan (n=1455) | Placebo (n=380) |
|---|---|---|
| Upper respiratory tract infection | 7 | 6 |
| Back pain | 3 | 1 |
| Sinusitis | 3 | 2 |
| Diarrhea | 3 | 2 |
| Pharyngitis | 1 | 0 |
Placebo-controlled blood pressure trials of telmisartan alone at 20 to 160 mg for up to 12 weeks. Values are percent of patients. The label says side effects were not dose-related and did not track with gender, age or race.
Stopping because of adverse events: 2.8% of 1,455 people on telmisartan vs 6.1% of 380 on placebo.
Cough in 6 placebo-controlled trials was 1.6% on telmisartan, identical to placebo.
These occurred in at least 1% but were at least as frequent on placebo: influenza-like symptoms, dyspepsia, myalgia, urinary tract infection, abdominal pain, headache, dizziness, pain, fatigue, coughing, hypertension, chest pain, nausea and peripheral edema.
Lab changes: a hemoglobin drop of more than 2 g/dL in 0.8% on telmisartan vs 0.3% on placebo, and a creatinine rise of 0.5 mg/dL or more in 0.4% vs 0.3%. One person stopped because of rising creatinine and blood urea nitrogen.
In early studies, one case of angioedema was reported among 3,781 people treated.
Symptomatic dizziness on standing after the first dose was 0.04% across all controlled trials.
Reported after approval include headache, dizziness, weakness, swelling of the face or legs, angioedema (including with fatal outcome), low blood pressure on standing, high potassium, fainting, slow heart rate, erectile dysfunction, tendon pain, kidney impairment including acute kidney failure, low blood sugar in people with diabetes, and rare rhabdomyolysis.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Who should not take it. People with a known allergy, such as anaphylaxis or angioedema, to telmisartan or any ingredient, and people with diabetes who take aliskiren.
Fetal toxicity. Medicines acting on the renin-angiotensin system in the second and third trimesters reduce the baby's kidney function and raise the risk of harm and death to the fetus and newborn. Telmisartan is stopped as soon as pregnancy is detected.
Low blood pressure. In people low on fluid or salt, such as those on high-dose diuretics, low blood pressure with symptoms can happen after starting. The fluid or salt loss is corrected first, or treatment starts at a lower dose under close supervision.
High potassium. High potassium can occur, especially with advanced kidney disease, heart failure, dialysis, or with potassium supplements, potassium-sparing diuretics, potassium salt substitutes or other medicines that raise potassium. Periodic electrolyte checks are considered.
Liver impairment. Most telmisartan leaves the body in bile, so people with bile duct blockage or liver insufficiency clear it more slowly. It is started at low doses and raised slowly.
Kidney function changes. In people whose kidney function depends on the renin-angiotensin system, such as severe heart failure, drugs like telmisartan have been linked with low urine output, rising waste levels and, rarely, acute kidney failure or death. A similar effect is expected in renal artery stenosis.
Combining with other RAS blockers. Combining an ARB with an ACE inhibitor or aliskiren raises the risk of low blood pressure, high potassium and kidney changes. In ONTARGET (25,620 people), telmisartan plus ramipril added no benefit but more kidney problems. Aliskiren is not combined with telmisartan in diabetes and is avoided when GFR is under 60.
Drug interactions. Digoxin peak levels rose a median 49% and trough levels 20%, so digoxin levels are checked when telmisartan is started, changed or stopped. Lithium levels and toxicity can rise. NSAIDs, including COX-2 inhibitors, can worsen kidney function in some people and weaken the blood pressure effect.
Breastfeeding. Breastfeeding is not advised during treatment because of possible low blood pressure, high potassium and kidney problems in the baby.
From the Patient Information that comes with Telmisartan Tablets:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.