👤 By the CinnaRN Clinical Content Team🕐 Updated 2026-08-23🏷️ Pharmacological Therapies🔖 Free to read, print, and share
Also known as: Theo-Dur · Theo-24 · xanthine bronchodilator
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Use this quick-reference guide to spot, treat, and prevent Theophylline on the NCLEX. Keep it handy during review and on exam day!
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📒 The 1-minute cheat sheet
📌 Uses
COPD, chronic asthma (rare now)
Methylxanthine → bronchodilation
🧪 Labs
Therapeutic 10-20 mcg/mL
> 20 → toxic, monitor levels
🚩 Report
N/V, HA, insomnia = early toxicity
Tachycardia, seizures, arrhythmia
📌 Avoid
Caffeine → ↑ toxicity & jitters
Smoking ↓ levels; many drug interax
📚 Theophylline — full study notes
The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.
Theophylline is a methylxanthine bronchodilator that relaxes airway smooth muscle and is used for COPD and chronic asthma. It has a very narrow therapeutic range, so serum levels must be monitored closely. Memory aid: keep the level THEO-rapeutic at 10-20 mcg/mL.
Caffeine, smoking, and many drugs alter levels; smoking increases metabolism and lowers blood levels.
Early toxicity signs include nausea, vomiting, restlessness, insomnia, and tachycardia.
Severe toxicity causes seizures and life-threatening dysrhythmias.
Avoid caffeine-containing foods/beverages because they add to CNS and cardiac stimulation.
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Nursing priorities
What to do, in order
Monitor serum theophylline levels and report values outside 10-20 mcg/mL.
Assess heart rate and rhythm for tachycardia and dysrhythmias.
Hold the dose and notify the provider for nausea, vomiting, restlessness, or palpitations.
Review medication and smoking history for interactions that change drug levels.
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Red flags — report now
Escalate immediately
Report serum level over 20 mcg/mL or any seizures and dysrhythmias immediately.
Never ignore early GI or CNS stimulation symptoms, as they can precede severe toxicity.
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Labs & values
Numbers to know
Theophylline therapeutic level 10-20 mcg/mL
Toxicity > 20 mcg/mL
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Patient teaching
What patients must know
Take doses at the same time each day and do not chew or crush sustained-release tablets.
Limit caffeine (coffee, tea, cola, energy drinks, chocolate).
Tell your provider if you start or stop smoking, as it changes your dose needs.
Report nausea, vomiting, fast heartbeat, restlessness, or trouble sleeping.
❓ Theophylline: NCLEX FAQs
What are the priority nursing interventions for Theophylline?
Monitor serum theophylline levels and report values outside 10-20 mcg/mL. Assess heart rate and rhythm for tachycardia and dysrhythmias. Hold the dose and notify the provider for nausea, vomiting, restlessness, or palpitations. Review medication and smoking history for interactions that change drug levels.
What are the warning signs of Theophylline a nurse must report?
Report serum level over 20 mcg/mL or any seizures and dysrhythmias immediately. Never ignore early GI or CNS stimulation symptoms, as they can precede severe toxicity.
What do I need to know about Theophylline for the NCLEX?
Narrow therapeutic serum level is 10-20 mcg/mL; toxicity rises sharply above this. Caffeine, smoking, and many drugs alter levels; smoking increases metabolism and lowers blood levels. Early toxicity signs include nausea, vomiting, restlessness, insomnia, and tachycardia. Severe toxicity causes seizures and life-threatening dysrhythmias.
What patient teaching is important for Theophylline?
Take doses at the same time each day and do not chew or crush sustained-release tablets. Limit caffeine (coffee, tea, cola, energy drinks, chocolate). Tell your provider if you start or stop smoking, as it changes your dose needs. Report nausea, vomiting, fast heartbeat, restlessness, or trouble sleeping.