Prescription medication · Potassium-Sparing Diuretic / Aldosterone Antagonist
spironolactone
Also sold as Aldactone. Spironolactone is used to treat heart failure by reducing fluid build-up and helping you live longer.
Data updated 2026-05-15
- 133,996
- FDA reportsHeavily reported
- 23
- InteractionsSeveral interactions
- In shortage
- FDA status
What the data shows
spironolactone (Aldactone) is a prescription Potassium-Sparing Diuretic / Aldosterone Antagonist, more reported than roughly 9 in 10 tracked drugs (133,996 FDA reports), with 23 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
spironolactone (Aldactone) is a prescription Potassium-Sparing Diuretic / Aldosterone Antagonist. Spironolactone is used to treat heart failure by reducing fluid build-up and helping you live longer.
Spironolactone is a medicine that helps remove extra fluid from your body and lower blood pressure. It also helps your heart work better if you have heart failure.
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
spironolactone is currently listed as to be discontinued by the FDA. Affected manufacturer: Pfizer Inc..
View all drug shortages →Drug Pricing (NADAC)
Generic Price
$0.16/unit
Generic Available
Yes (14 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: SPIRONOLACTONE 100 MG TABLET
Same CMS presentation as the headline generic unit price above (2 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: +1.6% vs prior release.
| Effective | NADAC / unit | vs prior | NDCs |
|---|---|---|---|
| May 22, 2024 | $0.1618/EA | - | 3 |
| December 18, 2024 | $0.1644/EA | +1.6% | 24 |
What it does
Spironolactone is used to treat heart failure by reducing fluid build-up and helping you live longer.
Common side effects
Breast enlargement in men, Dizziness, Headache
Key warnings
Spironolactone can cause your potassium levels to get too high, which can be dangerous.
The sections below are summarized in plain English from spironolactone's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Spironolactone belongs to a class of drugs called aldosterone antagonists. It works by blocking the effects of aldosterone, a hormone that causes your body to hold onto salt and water. By blocking aldosterone, spironolactone helps your body get rid of extra fluid and salt, which lowers blood pressure and reduces strain on the heart.
Side Effects (from patient reports)
Based on 133,996 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for spironolactone, by number of reports
- Dyspnoea
Dyspnoea
10,389 reports
- Fatigue
Fatigue
8,178 reports
- Nausea
Nausea
7,818 reports
- Diarrhoea
Diarrhoea
7,418 reports
- Acute Kidney Injury
Acute Kidney Injury
6,785 reports
- Dizziness
Dizziness
6,238 reports
- Headache
Headache
5,859 reports
- Hypotension
Hypotension
5,819 reports
- Fall
Fall
5,094 reports
- Asthenia
Asthenia
4,987 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for spironolactone each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where spironolactone sits
spironolactone has more FDA adverse-event reports than 91% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is spironolactone; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 133,996 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2001–2025.
Total Reports
133,996
Reports Mentioning Death
17,638
13.2% of reports — not proof of cause
Hospitalization Reports
64,112
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DYSPNOEA | 10,389 |
| 2 | FATIGUE | 8,178 |
| 3 | NAUSEA | 7,818 |
| 4 | DIARRHOEA | 7,418 |
| 5 | ACUTE KIDNEY INJURY | 6,785 |
| 6 | DIZZINESS | 6,238 |
| 7 | HEADACHE | 5,859 |
| 8 | HYPOTENSION | 5,819 |
| 11 | FALL | 5,094 |
| 12 | ASTHENIA | 4,987 |
| 13 | HYPERKALAEMIA | 4,929 |
| 14 | DEATH | 4,916 |
| 15 | VOMITING | 4,849 |
| 16 | CARDIAC FAILURE | 4,485 |
| 17 | PNEUMONIA | 4,410 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Spironolactone can cause your potassium levels to get too high, which can be dangerous. Your doctor will check your potassium levels regularly, especially if you have kidney problems or are taking other medicines that can raise potassium. This medicine can also cause low blood pressure or make kidney problems worse. Tell your doctor if you have side effects.
Known Drug Interactions
Lithium: Increased risk of lithium toxicity ( 7.2 ). Examples of drugs that can increase potassium include: ACE inhibitors angiotensin receptor blockers non-steroidal anti-inflammatory drugs (NSAIDs) heparin and low molecular weight heparin trimethoprim 7.2 Lithium Like other diuretics, spironolactone reduces the renal clearance of lithium, thus increasing the risk of lithium toxicity. Monitor lithium levels periodically when spironolactone is co-administered [see Clinical Pharmacology (12.3) ] .
Mechanism: Spironolactone makes it harder for the kidneys to remove lithium from the body. This can cause lithium to build up to dangerous levels.
Examples of drugs that can increase potassium include: ACE inhibitors angiotensin receptor blockers non-steroidal anti-inflammatory drugs (NSAIDs) heparin and low molecular weight heparin trimethoprim 7.2 Lithium Like other diuretics, spironolactone reduces the renal clearance of lithium, thus increasing the risk of lithium toxicity.
Mechanism: Both of these medications can cause your body to hold onto potassium. Taking them together increases the risk of having too much potassium in your blood.
Examples of drugs that can increase potassium include: ACE inhibitors angiotensin receptor blockers non-steroidal anti-inflammatory drugs (NSAIDs) heparin and low molecular weight heparin trimethoprim 7.2 Lithium Like other diuretics, spironolactone reduces the renal clearance of lithium, thus increasing the risk of lithium toxicity.
Mechanism: Both drugs can raise the amount of potassium in your blood. Using them at the same time makes it more likely that your potassium levels will become too high.
Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) or potassium supplements can increase the risk of hyperkalemia. Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) or potassium supplements can increase the risk of hyperkalemia.
Mechanism: Both of these medications can cause your body to hold onto potassium instead of flushing it out. This can lead to dangerously high levels of potassium in your blood.
Hyperkalemia Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) can increase the risk of hyperkalemia.
Mechanism: Both of these medicines cause the body to hold onto potassium instead of getting rid of it through urine. This can lead to a dangerous buildup of potassium in your blood.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
Can I take spironolactone with food?
What should I do if I experience dizziness while taking spironolactone?
Will spironolactone affect my ability to drive?
How long does it take for spironolactone to start working?
Can spironolactone cause any changes in my period?
Does spironolactone interact with other medications?
Can I drink alcohol while taking spironolactone?
Will I need blood tests while taking spironolactone?
Can spironolactone cause breast enlargement in men?
What do the numbers on my pills mean?
What are the common side effects of spironolactone?
Does spironolactone interact with other medications?
What drug class is spironolactone?
What pregnancy or breastfeeding source fields are listed for spironolactone?
Has spironolactone been recalled?
Is spironolactone currently in shortage?
Active Recalls
Presence of foreign substance: identified as aluminum.
SUN PHARMACEUTICAL INDUSTRIES INC
Labeling: Label Mix-Up - Prepackaged bottles labeled spironolactone 50 mg may contain spironolactone 25 mg tablets.
Bryant Ranch Prepack, Inc. dba BRP Pharmaceuticals
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Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for spironolactone: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 133,996.
- insulin lispro Δ 202 reports · Rapid-Acting Insulin 134,198reports
- citalopram Δ 483 reports · Selective Serotonin Reuptake Inhibitor (SSRI) 133,513reports
- escitalopram Δ 540 reports · Selective Serotonin Reuptake Inhibitor (SSRI) 134,536reports
- abatacept Δ 769 reports · T-Cell Co-Stimulation Modulator 133,227reports
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 13.16%.
- calcitriol Δ 0.02 pts · 20,452 reports · Active Vitamin D (1,25-dihydroxy) 13.14%death share
- rivaroxaban Δ 0.04 pts · 203,269 reports · Direct Oral Anticoagulant (Factor Xa Inhibitor) 13.20%death share
- cyclosporine Δ 0.05 pts · 106,440 reports · Calcineurin Inhibitor (Immunosuppressant) 13.12%death share
- febuxostat Δ 0.05 pts · 16,005 reports · Xanthine Oxidase Inhibitor 13.11%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for spironolactone
The FDA label for spironolactone (sold under brand names such as Aldactone) classifies it as a prescription-only medication in the Potassium-Sparing Diuretic / Aldosterone Antagonist class. Spironolactone is used to treat heart failure by reducing fluid build-up and helping you live longer. Official labeling lists 3 commonly reported side effects, including Breast enlargement in men, Dizziness, Headache.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 133,996 voluntary reports. The database also lists 23 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.16.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 2 recall records on file), and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: January 13, 2025
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages