What the label lists and what reports show
Hydrochlorothiazide and telmisartan side effects
Hydrochlorothiazide and telmisartan's FDA label: “The most common adverse reactions (≥2% of patients) were upper respiratory tract infection, dizziness, sinusitis, diarrhea, fatigue, influenza-like symptoms, and nausea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Boehringer Ingelheim …” FAERS holds 2,354 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is dizziness (151 reports).
- Generic listed
- Boxed warning
Check it at the source: the hydrochlorothiazide and telmisartan FDA label on DailyMed (effective December 31, 2024, Boehringer Ingelheim Pharmaceuticals, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of MICARDIS HCT tablets?MICARDIS HCT tablets may cause serious side effects, including: Injury or death to your unborn baby. See " What is the most important information I should know about MICARDIS HCT tablets? " Low blood pressure (hypotension) is most likely to happen if you also: take water pills (diuretics) are on a low-salt diet get dialysis treatments have heart problems get sick with vomiting or diarrhea do not drink enough fluids sweat a lot If you feel faint or dizzy, lie down and call your doctor right away. Kidney problems, which may get worse if you already have kidney disease. You may have changes in your kidney test results, and you may need a lower dose of MICARDIS HCT tablets. Call your doctor if you get: swelling in your feet, ankles, or hands unexplained weight gain Call your doctor right away if you get any of the symptoms listed above. […]
Source: FDA drug label, Boehringer Ingelheim Pharmaceuticals, Inc., effective December 31, 2024 (SPL set b078dae2-664d-4144-847a-3b9d9b557402), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥2% of patients) were upper respiratory tract infection, dizziness, sinusitis, diarrhea, fatigue, influenza-like symptoms, and nausea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Boehringer Ingelheim Pharmaceuticals, Inc.
Table 1 Adverse Reactions Occurring at an Incidence of ≥2% in Patients Treated with Telmisartan/Hydrochlorothiazide and at a Greater Rate Than in Patients Treated with Placebo*
| Reaction | Telmisartan/Hydrochlorothiazide (n = 414) | Placebo (n = 74) | Telmisartan (n = 209) | Hydrochlorothiazide (n = 121) |
|---|---|---|---|---|
| Fatigue | 3% | 1% | 3% | 3% |
| Influenza-like symptoms | 2% | 1% | 2% | 3% |
| Central/Peripheral nervous system Dizziness | 5% | 1% | 4% | 6% |
| Diarrhea | 3% | 0% | 5% | 2% |
| Nausea | 2% | 0% | 1% | 2% |
| Respiratory system disorder Sinusitis | 4% | 3% | 3% | 6% |
| Upper respiratory tract infection | 8% | 7% | 7% | 10% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following adverse reactions are discussed elsewhere in labeling: Hypotension [see Warnings and Precautions (5.2) ] Renal Impairment [see Warnings and Precautions (5.3) ] Electrolytes and Metabolic Disorders [see Warnings and Precautions (5.4) ] The most common adverse reactions (≥2% of patients) were upper respiratory tract infection, dizziness, sinusitis, diarrhea, fatigue, influenza-like symptoms, and nausea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Boehringer Ingelheim Pharmaceuticals, Inc. at (800) 542-6257 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. MICARDIS HCT has been evaluated for safety in more than 1700 patients, including 716 treated for hypertension for longer than 6 months and 420 for more than 1 year. Adverse reactions have been limited to those that have been previously reported with telmisartan and/or hydrochlorothiazide. Adverse reactions occurring at an incidence of ≥2% in patients treated with telmisartan/hydrochlorothiazide and at a greater rate than in patients treated with placebo, are presented in Table 1 [see Clinical Studies (14) ].
Source: FDA drug label, Boehringer Ingelheim Pharmaceuticals, Inc., effective December 31, 2024 (SPL set b078dae2-664d-4144-847a-3b9d9b557402), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,354 reports list hydrochlorothiazide and telmisartan among the medicines taken, each a report of something that happened, not proof the medicine caused it; 145 are coded as a death and 760 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 22 reactions below, 15 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Hydrochlorothiazide and telmisartan: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions