About theophylline
Methylxanthine bronchodilator
Used for
- Long-term control of asthma symptoms
- Relief of airflow limitation in chronic obstructive pulmonary disease
Usual adult dose
Usually 200–400 mg every 12 hours; dosing is adjusted using blood levels and clinical response.
Usual dose in children
For children over 1 year, dosing is individualized by weight and blood-level monitoring.
Common side effects
- Nausea, vomiting, or stomach upset
- Headache, restlessness, or insomnia
- Fast or irregular heartbeat
- Seizures, especially with toxic blood levels
Important warnings
- Narrow safety range; blood-level monitoring is often needed.
- Toxicity can cause dangerous heart rhythms or seizures.
- Smoking, illness, and changes in liver function can alter blood levels.
- Swallow prolonged-release tablets whole; do not crush or chew.
Pregnancy
Use only when needed under medical supervision; pregnancy can change theophylline levels.
Breastfeeding
Passes into breast milk and may cause irritability or poor sleep in infants.
Interactions
- Some antibiotics, including ciprofloxacin, can raise theophylline levels.
- Cimetidine can raise levels; rifampicin can lower them.
- Smoking lowers levels; stopping smoking may raise them.
- Caffeine may increase stimulant effects and side effects.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.