What the label lists and what reports show
Atenolol and chlorthalidone side effects
Atenolol and chlorthalidone's FDA label lists its adverse reactions in its own words. FAERS holds 753 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 nausea (101 reports).
- Generic listed
Check it at the source: the atenolol and chlorthalidone FDA label on DailyMed (effective January 16, 2024, Unichem Pharmaceuticals (USA), Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsAtenolol and chlorthalidone tablets are usually well tolerated in properly selected patients. Most adverse effects have been mild and transient. The adverse effects observed for atenolol and chlorthalidone tablets are essentially the same as those seen with the individual components. Atenolol The frequency estimates in the following table were derived from controlled studies in which adverse reactions were either volunteered by the patient (US studies) or elicited, e.g., by checklist (foreign studies). The reported frequency of elicited adverse effects was higher for both atenolol and placebo-treated patients than when these reactions were volunteered. Where frequency of adverse effects for atenolol and placebo is similar, causal relationship to atenolol is uncertain.
A table the label prints in its adverse reactions section without a title; its column headings name the groups compared
| Reaction | Atenolol (n=164) % | Placebo (n=206) % | Atenolol (n=399) % | Placebo (n=407) % |
|---|---|---|---|---|
| Bradycardia | 3 | 0 | 3 | 0 |
| Cold Extremities | 0 | 0.5 | 12 | 5 |
| Postural Hypotension | 2 | 1 | 4 | 5 |
| Leg Pain | 0 | 0.5 | 3 | 1 |
| Dizziness | 4 | 1 | 13 | 6 |
| Vertigo | 2 | 0.5 | 2 | 0.2 |
| Light-Headedness | 1 | 0 | 3 | 0.7 |
| Tiredness | 0.6 | 0.5 | 26 | 13 |
| Fatigue | 3 | 1 | 6 | 5 |
| Lethargy | 1 | 0 | 3 | 0.7 |
| Drowsiness | 0.6 | 0 | 2 | 0.5 |
| Depression | 0.6 | 0.5 | 12 | 9 |
| Dreaming | 0 | 0 | 3 | 1 |
| Diarrhea | 2 | 0 | 3 | 2 |
| Nausea | 4 | 1 | 3 | 1 |
| Wheeziness | 0 | 0 | 3 | 3 |
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.
Source: FDA drug label, Unichem Pharmaceuticals (USA), Inc., effective January 16, 2024 (SPL set a85d28c1-e812-4c12-aa67-136bff3610e5), via openFDA; the full label on DailyMed
What do FAERS reports show?
753 reports list atenolol and chlorthalidone among the medicines taken, each a report of something that happened, not proof the medicine caused it; 61 are coded as a death and 264 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 21 reactions below, 7 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?
- Atenolol and chlorthalidone: 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