Prescription medication · Methylxanthine Bronchodilator
theophylline
Also sold as Theo-24, Elixophyllin. Theophylline treats the symptoms of long-term asthma and other lung diseases.
Data updated 2026-05-15
- 11,723
- FDA reportsModerately reported
- 86
- InteractionsMany interactions
- 1
- Recall record
What the data shows
theophylline (Theo-24) is a prescription Methylxanthine Bronchodilator, reported less often than most tracked drugs (11,723 FDA reports), with 86 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.
theophylline (Theo-24) is a prescription Methylxanthine Bronchodilator. Theophylline treats the symptoms of long-term asthma and other lung diseases.
Theophylline is a medicine that helps you breathe easier. It treats the symptoms of asthma and other lung problems.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.09/unit
Generic Available
Yes (21 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: THEOPHYLLINE 80 MG/15 ML SOLN
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 |
|---|---|---|---|
| October 23, 2024 | $0.0961/ML | - | 1 |
| December 18, 2024 | $0.0945/ML | -1.6% | 2 |
What it does
Theophylline treats the symptoms of long-term asthma and other lung diseases.
Common side effects
Nausea, Vomiting, Headache
Key warnings
If your theophylline levels get too high in your blood, it can cause serious side effects.
The sections below are summarized in plain English from theophylline's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Theophylline is a bronchodilator. It works by relaxing the muscles in your airways. This allows more air to flow in and out of your lungs.
Side Effects (from patient reports)
Based on 11,723 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for theophylline, by number of reports
- Dyspnoea
Dyspnoea
2,273 reports
- Asthma
Asthma
1,942 reports
- Pneumonia
Pneumonia
1,318 reports
- Wheezing
Wheezing
1,306 reports
- Vomiting
Vomiting
1,101 reports
- Cough
Cough
1,058 reports
- Drug Hypersensitivity 824
Drug Hypersensitivity
824 reports
- Malaise 751
Malaise
751 reports
- Pain 699
Pain
699 reports
- Oedema 667
Oedema
667 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 theophylline 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 theophylline sits
theophylline has more FDA adverse-event reports than 43% 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 theophylline; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 11,723 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 1995–2025.
Total Reports
11,723
Reports Mentioning Death
1,708
14.6% of reports — not proof of cause
Hospitalization Reports
5,109
Top Indication
Asthma
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DYSPNOEA | 2,273 |
| 2 | ASTHMA | 1,942 |
| 3 | PNEUMONIA | 1,318 |
| 4 | WHEEZING | 1,306 |
| 5 | VOMITING | 1,101 |
| 6 | COUGH | 1,058 |
| 7 | DRUG HYPERSENSITIVITY | 824 |
| 9 | MALAISE | 751 |
| 10 | PAIN | 699 |
| 11 | OEDEMA | 667 |
| 12 | CHEST PAIN | 633 |
| 13 | NAUSEA | 630 |
| 14 | CHRONIC OBSTRUCTIVE PULMONARY DISEASE | 626 |
| 15 | FATIGUE | 480 |
| 16 | DIZZINESS | 474 |
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
If your theophylline levels get too high in your blood, it can cause serious side effects. These include severe vomiting, irregular heartbeats, and seizures. These can be life-threatening.
Known Drug Interactions
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...
Mechanism: Metoprolol is a beta-blocker that can block the airway-opening effects of theophylline. This combination can make it harder for you to breathe and may change the amount of medicine in your blood.
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...
Mechanism: Both of these medicines are used to open the airways, and taking them together can cause a racing heart, shakiness, or other stimulant-like side effects.
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...
Mechanism: Omeprazole does not change how fast your body breaks down and gets rid of theophylline.
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...
Mechanism: Amoxicillin does not change the way your body processes or removes theophylline.
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...
Mechanism: Famotidine does not affect the amount of theophylline that stays 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 chew or crush the tablets?
What should I do if I miss a dose?
Can I take this medicine with other medicines?
What are the common side effects?
How should I store this medicine?
Can I drink coffee or other caffeinated drinks while taking this?
How long does it take for the medicine to work?
What if I accidentally take too much?
Can I split the tablets?
Should I take this with food?
What are the common side effects of theophylline?
Does theophylline interact with other medications?
What drug class is theophylline?
What pregnancy or breastfeeding source fields are listed for theophylline?
Has theophylline been recalled?
Active Recalls
OOS results reported for the Dissolution (by UV) test.
Glenmark Pharmaceuticals Inc., USA
Related Medications in Methylxanthine Bronchodilator
Other drugs grouped near theophylline - same-class peers and common alternatives.
aclidinium
Tudorza Pressair
Compare with theophylline →
albuterol
Ventolin, ProAir
Albuterol is a drug that helps you breathe easier.
Compare with theophylline →
albuterol/ipratropium
Combivent Respimat, DuoNeb
Combivent Respimat is a combination medicine that helps open your airways.
Compare with theophylline →
beclomethasone
Qvar
Qvar Redihaler is an inhaled medicine that helps control asthma symptoms.
Compare with theophylline →
benralizumab
Fasenra
Fasenra is a medicine that can help treat severe asthma and EGPA.
Compare with theophylline →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for theophylline: 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: 11,723.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 14.57%.
- quetiapine Δ 0.03 pts · 185,533 reports · Atypical Antipsychotic 14.54%death share
- roflumilast Δ 0.05 pts · 6,450 reports · PDE4 Inhibitor 14.62%death share
- diltiazem Δ 0.06 pts · 33,620 reports · Calcium Channel Blocker 14.63%death share
- fluvastatin Δ 0.06 pts · 3,948 reports · HMG-CoA Reductase Inhibitor (Statin) 14.51%death share
Medication Guides
Understanding Drug Interactions
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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 theophylline
The FDA label for theophylline (sold under brand names such as Theo-24, Elixophyllin) classifies it as a prescription-only medication in the Methylxanthine Bronchodilator class. Theophylline treats the symptoms of long-term asthma and other lung diseases. Official labeling lists 4 commonly reported side effects, including Nausea, Vomiting, Headache.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 11,723 voluntary reports. The database also lists 86 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $0.09.
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 1 recall record 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).
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: December 4, 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