What it means
theophyllinethee-OFF-ih-linA bronchodilator taken by mouth that relaxes and opens the airways, used long term for asthma and COPD.Full entry , an older drug for asthma and COPD, has a narrow therapeutic range. Smoking lowers the level, while heart failure, liver disease, older age and drugs such as ciprofloxacin and cimetidine raise it. Too high a level causes nausea, vomiting, restlessness, a fast heart rate and, in severe cases, dangerous heart rhythms and seizures.
For the nurse
Teach clients to tell the provider if they start or stop smoking, to limit caffeine, and to report nausea, a racing heart or tremors.
At a glance
| Normal range | Often 5–15 mcg/mL [28–83 µmol/L]; some labs use 10–20 mcg/mL [55–111 µmol/L]. |
|---|---|
| Critical range | Toxicity becomes likely above 20 mcg/mL [111 µmol/L]; each lab sets its own critical value. |
| Also written | serum theophylline level, theophylline levels |
Related terms
COPD
Chronic obstructive pulmonary disease: a long-term lung disease that makes it hard to move air out of the lungs.
asthma
A long-term lung disease in which the airways become inflamed and narrow from time to time.
theophylline
A bronchodilator taken by mouth that relaxes and opens the airways, used long term for asthma and COPD.