Hydrochlorothiazide vs Spironolactone: side effects in FDA adverse event reports
At a glance
| Hydrochlorothiazide | Spironolactone | |
|---|---|---|
| Drug class | Thiazide Diuretic | Aldosterone Antagonist |
| Brand names | – | – |
| FAERS reports | 144,362 | 139,599 |
| Serious | 67% | 78% |
| Death outcome | 10,118 | 18,066 |
| Boxed warning | No | No |
Signals both drugs share
| Reaction | Hydrochlorothiazide | Spironolactone | Label screen (A / B) |
|---|---|---|---|
| Nephrogenic anaemia | 531 · PRR 18.5 | 357 · PRR 12.3 | Likely indication confounding / Likely indication confounding |
| Atrial tachycardia | 436 · PRR 37.7 | 161 · PRR 12.3 | Not in label — unassessed / Not in label — unassessed |
| Hyperparathyroidism secondary | 270 · PRR 17.2 | 177 · PRR 11.2 | Not in label — unassessed / Likely indication confounding |
Labeled signals distinctive to Hydrochlorothiazide
- Vasculitis — n=630, PRR 8.2 Labeled adverse reaction
- Tension headache — n=434, PRR 16.2 Labeled (related wording)
- Respiratory symptom — n=149, PRR 8.1 Labeled (related wording)
- Pulmonary vasculitis — n=131, PRR 47.7 Labeled (related wording)
Labeled signals distinctive to Spironolactone
- Hyperkalaemia — n=5,027, PRR 25.1 Labeled adverse reaction
Common questions
Which has more reported side effects, Hydrochlorothiazide or Spironolactone?
Hydrochlorothiazide has 144,362 FAERS reports and Spironolactone 139,599. More reports does not mean more dangerous: volume follows how widely and how long a drug has been used, prescription vs over-the-counter status, and publicity. The seriousness share (67% vs 78%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Hydrochlorothiazide and Spironolactone share?
Both drugs carry disproportionality signals for nephrogenic anaemia, atrial tachycardia, hyperparathyroidism secondary. Shared signals often reflect a shared drug class or the condition both are used for.
Is Hydrochlorothiazide or Spironolactone safer?
FAERS cannot answer that: it has no denominator and no comparator. Use this page to see which risks are already on each label and which signals are unlabeled, then check the prescribing information and your clinician for your situation.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, openFDA count queries for seriousness and deaths. Pair chosen because it is a commonly searched comparison. Generated 2026-10-08.