Pharmacologic class (EPC) · 2 drug pages

Methylxanthine: adverse event reports filed with FDA

5,061 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

5,061
reports across the class: 0% of all reports; 543
reports, 12 months to June 2026: 477 in the 12 months before; 95.3%
marked serious by the reporter: 57.4% across all reports; 2
drugs with a page: brand and generic names counted separately

Methylxanthine is a pharmacologic class (an FDA Established Pharmacologic Class) with 2 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 5,061 adverse event reports received by FDA, 0% of the database, from January 2004 to June 2026.

543 reports arrived in the 12 months to June 2026, up 14% from 477 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 95.3% of the class's reports are marked serious, 17% record death among the outcomes and 42.8% record hospitalisation, as reported.

Across the class the reactions recorded most often are asthma (35.1%), dyspnoea (33.2%) and wheezing (28.7%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Theophylline	generic	4,050	384	95.3%	Asthma
Aminophylline	generic	1,011	159	95.5%	Dyspnoea

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Asthmaasthma35.1%1,775
Dyspnoeashortness of breath33.2%1,681
Wheezingwheezing28.7%1,450
Vomitingbeing sick25.3%1,281
Drug hypersensitivityan allergic-type reaction to a medicine23%1,165
Pneumonialung infection23%1,165
Oedemaswelling from fluid19.4%982
Coughcough16.8%851
Malaisegeneral feeling of being unwell14%711
Painpain, site not specified12.8%650
Chest painchest pain11.8%595
Respiratory tract infectiona respiratory infection10.1%513
Therapeutic product effect incomplete8.2%416
Drug ineffectivethe medicine did not work as expected7.9%402
Toxicity to various agentspoisoning or toxic effect of one or more substances7.7%392
Off label useused for a purpose or in a way not on the label7.3%369
Lower respiratory tract infectiona chest infection6.7%340
Drug interactionan interaction between medicines6.7%338
Nasal oedema6.5%331
Overdosea dose above the recommended amount6%303
Loss of personal independence in daily activities5.9%301
Productive cougha cough with phlegm5.8%292
Chronic obstructive pulmonary diseaseCOPD, a long-term lung disease5.2%262
Chest discomfortchest discomfort4.9%250
Nauseafeeling sick4.9%246

Solid bar: share of all class reports. Hollow bar: the median share across the 2 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death17%862

Life-threatening12.1%611

Hospitalisation (initial or prolonged)42.8%2,164

Disability4.6%231

Congenital anomaly2.4%120

Other serious68.9%3,486

Not serious4.7%238

Patient age

Under 21.4%71

2 to 112.1%107

12 to 171.2%60

18 to 449.6%485

45 to 6417.7%898

65 to 7432.2%1,629

75 and over15.6%789

Age not given20.2%1,022

Who reported

Physician27.2%1,378

Pharmacist4.2%214

Other health professional43.8%2,217

Lawyer0%2

Consumer or non-health professional18.7%944

Not given6%306

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Methylxanthine reports

Which drugs are in the Methylxanthine class on this site?

Theophylline and Aminophylline. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

5,061 reports through June 2026, 543 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

asthma (35.1%), dyspnoea (33.2%), wheezing (28.7%), vomiting (25.3%) and drug hypersensitivity (23%).

Can the members table be used to rank the drugs?

No. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.