theophylline Side Effects
Also known as: Theo-24, Elixophyllin
Analysis of 11,723 adverse event reports submitted to the FDA from 1995 to 2025.
Total Reports
11,723
Death-Related
1,708
14.6% of reports
Hospitalizations
5,109
43.6% of reports
Top Indication
Asthma
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 1,708 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 351 |
| CHRONIC OBSTRUCTIVE PULMONARY DISEASE | 200 |
| DYSPNOEA | 185 |
| TOXICITY TO VARIOUS AGENTS | 152 |
| PNEUMONIA | 141 |
| RESPIRATORY FAILURE | 124 |
| COMPLETED SUICIDE | 105 |
| VOMITING | 105 |
| CONDITION AGGRAVATED | 104 |
| ANAEMIA | 103 |
| NAUSEA | 102 |
| SEPSIS | 100 |
| DRUG INEFFECTIVE | 90 |
| SOMNOLENCE | 88 |
| CARDIAC ARREST | 85 |
| DRUG INTERACTION | 83 |
| OFF LABEL USE | 83 |
| ABDOMINAL DISTENSION | 79 |
| GENERAL PHYSICAL HEALTH DETERIORATION | 78 |
| ABDOMINAL PAIN | 76 |
Reactions in Hospitalization Reports
Top reactions in 5,109 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| DYSPNOEA | 1,026 |
| ASTHMA | 850 |
| PNEUMONIA | 595 |
| CHRONIC OBSTRUCTIVE PULMONARY DISEASE | 497 |
| WHEEZING | 477 |
| COUGH | 407 |
| VOMITING | 383 |
| NAUSEA | 379 |
| DRUG INEFFECTIVE | 323 |
| THERAPEUTIC PRODUCT EFFECT INCOMPLETE | 316 |
| CONDITION AGGRAVATED | 302 |
| HYPERTENSION | 289 |
| FATIGUE | 276 |
| ANXIETY | 271 |
| PRODUCTIVE COUGH | 268 |
| ATRIAL FIBRILLATION | 261 |
| OFF LABEL USE | 257 |
| PYREXIA | 257 |
| DIZZINESS | 255 |
| DRUG INTERACTION | 237 |
Nearby — Related Medications
What the FAERS Data Reveals About theophylline Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 11,723 voluntary reports linked to theophylline and its brand equivalents (Theo-24, Elixophyllin), spanning 1995 through 2025. Of those, 1,708 (14.6%) listed death as an outcome and 5,109 (43.6%) involved hospitalization. The most common indication reported alongside adverse events was Asthma.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 59% were female and 40% male; age distribution skews toward 45-64, with 2,683 reports in that bracket. The single most reported reaction is dyspnoea with 2,273 submissions, followed by asthma and pneumonia.
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.
Read our methodology — how this data is sourced, computed, and verified.