Prescription medication · Methylxanthine Bronchodilator

theophylline

Name: theophylline - FDA Drug Safety & Adverse Event Data
Creator: PlainMeds
License: https://creativecommons.org/publicdomain/zero/1.0/

Also sold as Theo-24, Elixophyllin. Theophylline treats the symptoms of long-term asthma and other lung diseases.

Compiled by PlainMeds Editorial, Drug Information Editorial Team

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 →

View Alternatives → Compare with Another Drug → Full Side Effects Report →

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.

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.

This is a plain-language summary of theophylline's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.

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.

This is a plain-language summary of theophylline's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.

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.

This is a plain-language summary of theophylline's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.

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 11,723 FDA adverse event reports.

Difficulty breathing

2,273
Asthma

1,942
Pneumonia

1,317
Wheezing

1,306
Vomiting

1,101
Cough

1,058
Allergic reaction to the medicine

824
Feeling unwell

751
Pain

698
Swelling

667

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.

fewest reports most reports

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

Female 6,422 (59%)

Male 4,405 (40%)

Age Distribution

0–17 334

18–44 895

45–64 2,683

65–74 2,662

75+ 1,909

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

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

Reactions in Hospitalization Reports

DYSPNOEA 1,026

ASTHMA 850

PNEUMONIA 595

CHRONIC OBSTRUCTIVE PULMONARY DISEASE 497

WHEEZING 477

COUGH 407

VOMITING 383

NAUSEA 379

THERAPEUTIC PRODUCT EFFECT INCOMPLETE 316

CONDITION AGGRAVATED 302

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

major metoprolol

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.

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.

major albuterol

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.

major omeprazole

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.

major amoxicillin

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.

major famotidine

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.

Check all your medications →

This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.

Common Questions

Can I chew or crush the tablets?

No, do not chew or crush the tablets. Swallow them whole or split them if they are scored.

What should I do if I miss a dose?

Take it as soon as you remember. If it's almost time for your next dose, skip the missed dose.

Can I take this medicine with other medicines?

Theophylline can interact with many other medicines. Tell your doctor about all the medicines you take.

What are the common side effects?

Common side effects include nausea, vomiting, headache, and trouble sleeping.

How should I store this medicine?

Store it at room temperature in a tightly closed, light-resistant container.

Can I drink coffee or other caffeinated drinks while taking this?

Theophylline has caffeine-like effects, so limit caffeine intake to avoid increased side effects.

How long does it take for the medicine to work?

It may take a few days to feel the full effects of the medicine. Talk to your doctor if you don't feel better.

What if I accidentally take too much?

Seek medical attention immediately. Overdoses can be dangerous.

Can I split the tablets?

Yes, the scored tablet may be split.

Should I take this with food?

Yes, it is recommended to take theophylline with food.

What are the common side effects of theophylline?

The most commonly reported side effects of theophylline include Nausea, Vomiting, Headache, Trouble sleeping (insomnia). Based on 11,723 FDA adverse event reports. Always consult your healthcare provider about potential side effects.

Does theophylline interact with other medications?

Yes, theophylline has 86 known drug interactions. Notable interactions include metoprolol, albuterol, omeprazole. Always inform your doctor about all medications you are taking.

What drug class is theophylline?

theophylline belongs to the Methylxanthine Bronchodilator drug class. It requires a prescription (Rx). Theophylline treats the symptoms of long-term asthma and other lung diseases.

Is theophylline safe during pregnancy?

It is not known if theophylline can harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.

Has theophylline been recalled?

There is 1 recall associated with theophylline products. OOS results reported for the Dissolution (by UV) test. Check the recalls section below for full details and affected products.

Active Recalls

Class II May 15, 2025

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.

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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 theophylline vs aclidinium side-by-side →

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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 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.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.

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