theophylline
Brand names: Theo-24, Elixophyllin
Theophylline is a medicine that helps you breathe easier. It treats the symptoms of asthma and other lung problems.
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 →
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.
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.
How to Take It
Take theophylline tablets once a day, either in the morning or evening. It is best to take it with food. Always take it the same way, either always with food or always without food. Do not chew or crush the tablets, but you can split the scored tablet.
Pregnancy & Breastfeeding
It is not known if theophylline can harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if theophylline passes into breast milk, so talk to your doctor if you are breastfeeding.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and take your next dose at the regular time.
Storage
Store the medicine at room temperature (68° to 77°F) in a tightly closed, light-resistant container.
Side Effects (from patient reports)
Based on 12,026 FDA adverse event reports.
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
Death-Related Reports
1,708
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 |
| 8 | DRUG INEFFECTIVE | 756 |
| 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 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) 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, s...
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.
What to do: Your doctor may need to adjust your dosages or monitor your blood levels closely. Report any new breathing difficulties to your healthcare provider immediately.
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, s...
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.
What to do: Your doctor should monitor you for side effects like a fast heartbeat or tremors. They may need to adjust your doses to ensure the combination is safe for you.
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, s...
Mechanism: Omeprazole does not change how fast your body breaks down and gets rid of theophylline.
What to do: You can usually take these two medicines together without changing your dose.
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, s...
Mechanism: Amoxicillin does not change the way your body processes or removes theophylline.
What to do: No special changes to your medication are usually needed when taking these together.
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, s...
Mechanism: Famotidine does not affect the amount of theophylline that stays in your blood.
What to do: These medicines are generally safe to use together.
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?
Is theophylline safe during pregnancy?
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
Duaklir Pressair is a combination medicine used to help people with COPD breathe better.
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 →
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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 12,026 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 further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
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. Always consult a healthcare professional before making medication decisions.
Last updated: December 4, 2025
Read our methodology — how this data is sourced, computed, and verified.
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