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What the label lists and what reports show

Theophylline side effects

Theophylline's FDA label lists its adverse reactions in its own words. FAERS holds 12,327 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is dyspnoea (2,440 reports).

  • Generic listed

Check it at the source: the theophylline FDA label on DailyMed (effective March 10, 2026, Strides Pharma Science Limited); the FDA FAERS public dashboard.

What does the label list?

From the label: adverse reactions

Adverse reactions associated with theophylline are generally mild when peak serum theophylline concentrations are <20 mcg/mL and mainly consist of transient caffeine-like adverse effects such as nausea, vomiting, headache, and insomnia. When peak serum theophylline concentrations exceed 20 mcg/mL, however, theophylline produces a wide range of adverse reactions including persistent vomiting, cardiac arrhythmias, and intractable seizures which can be lethal (see OVERDOSAGE ). The transient caffeine-like adverse reactions occur in about 50% of patients when theophylline therapy is initiated at doses higher than recommended initial doses (e.g., >300 mg/day in adults and >12 mg/kg/day in children beyond >1 year of age). …

Source: FDA drug label, Strides Pharma Science Limited, effective March 10, 2026 (SPL set b7a90ccf-9c32-40cc-9008-7e55b3da4dfd), via openFDA; the full label on DailyMed

What do FAERS reports show?

12,327 reports list theophylline among the medicines taken, each a report of something that happened, not proof the medicine caused it; 1,787 are coded as a death and 5,350 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 4 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.

Reports received each year

The 25 most reported reactions

  • Dyspnoea2,440
  • Asthma (a use or a product term, not a reaction)2,098
  • Pneumonia1,468
  • Wheezing1,417
  • Vomiting (named in the label)1,230
  • Cough1,117
  • Drug Hypersensitivity940
  • Malaise825
  • Drug Ineffective (a use or a product term, not a reaction)805
  • Oedema770
  • Pain766
  • Chest Pain686
  • Nausea (named in the label)668
  • Chronic Obstructive Pulmonary Disease (named in the label)660
  • Fatigue504
  • Dizziness502
  • Off Label Use (a use or a product term, not a reaction)477
  • Condition Aggravated (a use or a product term, not a reaction)466
  • Productive Cough459
  • Pyrexia451
  • Respiratory Tract Infection440
  • Therapeutic Product Effect Incomplete (a use or a product term, not a reaction)439
  • Chest Discomfort405
  • Drug Interaction (a use or a product term, not a reaction)402
  • Headache (named in the label)402

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms

What next?

Theophylline: the full record
label, generics, price, shortages, recalls
Side effects hub
the most reported medicines and reactions