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What the label lists and what reports show

Spironolactone side effects

Spironolactone's FDA label: “The most common adverse reaction with ALDACTONE treatment is gynecomastia ( 5.4 , 6 ).” FAERS holds 139,757 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 dyspnoea (10,837 reports).

  • Generic listed
  • A presentation discontinued

Check it at the source: the spironolactone FDA label on DailyMed (effective November 28, 2025, Pfizer Laboratories Div Pfizer Inc); the FDA FAERS public dashboard.

What does the label list?

From the label: adverse reactions

The most common adverse reaction with ALDACTONE treatment is gynecomastia ( 5.4 , 6 ).

From the label: adverse reactions, continued

The following clinically significant adverse reactions are described elsewhere in the labeling: • Hyperkalemia [see Warnings and Precautions (5.1) ] • Hypotension and Worsening Renal Function [see Warnings and Precautions (5.2) ] • Electrolyte and Metabolic Abnormalities [see Warnings and Precautions (5.3) ] • Gynecomastia [see Warnings and Precautions (5.4 ] • Impaired neurological function/ coma in patients with hepatic impairment, cirrhosis and ascites [see Use in Specific Populations (8.7) ] The following adverse reactions associated with the use of spironolactone were identified in clinical trials or postmarketing reports. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency, reliably, or to establish a causal relationship to drug exposure. Digestive: Gastric bleeding, ulceration, gastritis, diarrhea and cramping, nausea, vomiting. Reproductive: Decreased libido, inability to achieve or maintain erection, irregular menses or amenorrhea, postmenopausal bleeding, breast and nipple pain. Hematologic: Leukopenia (including agranulocytosis), thrombocytopenia. Hypersensitivity: Fever, urticaria, maculopapular or erythematous cutaneous eruptions, anaphylactic reactions, vasculitis. …

Source: FDA drug label, Pfizer Laboratories Div Pfizer Inc, effective November 28, 2025 (SPL set 0fed2822-3a03-4b64-9857-c682fcd462bc), via openFDA; the full label on DailyMed

What do FAERS reports show?

139,757 reports list spironolactone among the medicines taken, each a report of something that happened, not proof the medicine caused it; 18,069 are coded as a death and 66,281 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, 8 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

  • Dyspnoea10,837
  • Fatigue8,573
  • Nausea (named in the label)8,155
  • Diarrhoea (named in the label)7,805
  • Acute Kidney Injury7,007
  • Dizziness (named in the label)6,528
  • Headache (named in the label)6,229
  • Hypotension (named in the label)6,025
  • Off Label Use (a use or a product term, not a reaction)5,938
  • Drug Ineffective (a use or a product term, not a reaction)5,419
  • Fall5,249
  • Asthenia5,178
  • Death (an outcome recorded in the report)5,085
  • Vomiting (named in the label)5,058
  • Hyperkalaemia (named in the label)5,027
  • Cardiac Failure4,593
  • Malaise4,573
  • Pneumonia4,571
  • Pain4,538
  • Cough4,292
  • Drug Interaction (a use or a product term, not a reaction)3,992
  • Anaemia3,886
  • Weight Decreased3,824
  • Oedema Peripheral3,813
  • Renal Failure (named in the label)3,700

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms

What next?

Spironolactone: the full record
label, generics, price, shortages, recalls
Side effects hub
the most reported medicines and reactions