Drug side effects
propylthiouracil Side Effects
The reactions most often reported to the FDA for propylthiouracil (also sold as PTU), with demographics, serious outcomes, and reporting trends.
Data updated 2026-05-15
- 1,982
- FAERS reports
Data from the FDA Adverse Event Reporting System (FAERS), 2004 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.
The most commonly reported side effects of propylthiouracil come from 1,982 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.
This page analyzes 1,982 reports to the FDA Adverse Event Reporting System (FAERS) for propylthiouracil (PTU): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.
Total Reports
1,982
Reports Mentioning Death
170
8.6% of reports — not proof the medicine caused the death
Hospitalizations
907
45.8% of reports
Top Indication
Hyperthyroidism
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 170 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| CARDIAC ARREST | 23 |
| DEATH | 21 |
| MULTIPLE ORGAN DYSFUNCTION SYNDROME | 19 |
| ACUTE KIDNEY INJURY | 14 |
| RENAL FAILURE | 13 |
| CARDIAC FAILURE CONGESTIVE | 11 |
| ACUTE HEPATIC FAILURE | 10 |
| PNEUMONIA | 10 |
| CIRCULATORY COLLAPSE | 9 |
| DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS | 9 |
| HYPERTHYROIDISM | 9 |
| HYPOTENSION | 9 |
| NAUSEA | 9 |
| SEPTIC SHOCK | 9 |
| CARDIOGENIC SHOCK | 8 |
| CHRONIC KIDNEY DISEASE | 8 |
| END STAGE RENAL DISEASE | 8 |
| THYROTOXIC CRISIS | 8 |
| CARDIO-RESPIRATORY ARREST | 7 |
Reactions in Hospitalization Reports
Top reactions in 907 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| HYPERTHYROIDISM | 82 |
| HYPOTENSION | 49 |
| NAUSEA | 45 |
| AGRANULOCYTOSIS | 42 |
| PYREXIA | 41 |
| VOMITING | 36 |
| ACUTE KIDNEY INJURY | 35 |
| ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY POSITIVE VASCULITIS | 35 |
| THYROTOXIC CRISIS | 35 |
| ACUTE HEPATIC FAILURE | 33 |
| CARDIOGENIC SHOCK | 31 |
| CONDITION AGGRAVATED | 30 |
| PNEUMONIA | 30 |
| CARDIAC ARREST | 29 |
| DIARRHOEA | 28 |
| ANAEMIA | 27 |
| FATIGUE | 27 |
| FOETAL EXPOSURE DURING PREGNANCY | 26 |
Nearby, Related Medications
What the FAERS Data Reveals About propylthiouracil Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 1,982 voluntary reports linked to propylthiouracil and its brand equivalents (PTU), spanning 2004 through 2025. Of those, 170 (8.6%) listed death as an outcome and 907 (45.8%) involved hospitalization. The most common indication reported alongside adverse events was Hyperthyroidism.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 73% were female and 26% male; age distribution skews toward 18-44, with 577 reports in that bracket. The single most reported reaction is hyperthyroidism with 135 submissions, followed by foetal exposure during pregnancy and nausea.
How to read these numbers
FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice, speak with a licensed clinician about any side-effect concerns.
Drugs With a Similar FAERS Report Volume
Other medications with a total FDA adverse-event report count closest to propylthiouracil's 1,982.
Read our methodology - how this data is sourced, computed, and verified.