- ACRONYMS AND DEFINITIONS
- COPD - Chronic obstructive pulmonary disease
- GINA - Global Initiative for Asthma
- GOLD - Global Initiative for Chronic Obstructive Lung Disease
- ICS - Inhaled corticosteroids
- LAMA - Lomg-acting muscarinic antagonist
- LABA - Long-acting beta agonists
- NHLBI - National Heart, Lung, and Blood Institute
- RCT - Randomized controlled trial
- DRUGS IN CLASS
- Methylxanthines
- Theophylline (Theo-24®, Elixophyllin®, Theochron®)
- MECHANISM OF ACTION
- Theophylline has two distinct actions in the airways of patients with reversible obstruction: smooth muscle relaxation (bronchodilation) and suppression of the response of the airways to stimuli
- While the mechanisms of action of theophylline are not known with certainty, studies in animals suggest that bronchodilation is mediated by the inhibition of two isozymes of phosphodiesterase (PDE III and to a lesser extent, PDE IV)
- Some of the adverse effects associated with theophylline appear to be mediated by inhibition of PDE III (e.g. hypotension, tachycardia, headache, and emesis) and adenosine receptor antagonism (e.g. alterations in cerebral blood flow)
- Theophylline increases the force of contraction of diaphragmatic muscles. This action appears to be due to enhancement of calcium uptake through an adenosine-mediated channel.
- FDA-APPROVED INDICATIONS
- Asthma and COPD
- Theophylline is indicated for the treatment of the symptoms and reversible airflow obstruction associated with chronic asthma and other chronic lung diseases (e.g. emphysema and chronic bronchitis)
- ASTHMA
- Overview
- Theophylline is an older drug that is used to treat asthma. Theophylline is not widely prescribed anymore because newer therapies are more effective and have fewer side effects. Another downside to theophylline therapy is that the drug requires blood monitoring due to its narrow therapeutic index.
- A study that compared theophylline to placebo in asthmatics receiving an ICS/LABA is summarized below
- STUDY
- Design: Randomized controlled trial (N=325, length = 24 weeks) in asthmatics
- Exposure: Theophylline 200 mg twice daily or Placebo. All patients received salmeterol/fluticasone 50/250 twice daily.
- Primary outcome: Level of asthma control (assessed by the Asthma Control Test) and the number of patients experiencing ≥ 1 exacerbations during the 24-week treatment period. Testing of lung function as well as measurement of the levels of inflammatory markers in induced sputum was performed.
- Results:
- Level of asthma control: No significant difference
- Number of patients with ≥ 1 asthma exacerbation: Theophylline group - 30%, Placebo - 47% (p=0.004)
- FEV1 at 24 weeks: No significant difference
- Findings: The combination of theophylline plus SFC may provide greater protection against asthma exacerbations, and its administration is accompanied by significant improvements in small airway function and airway inflammation
- Professional recommendations
- The 2019 GINA guidelines state that theophylline is not recommended for routine use due to its potential side effects and weak efficacy. The 2020 NHLBI guidelines do not mention theophylline.
- See asthma review for more
- COPD
- Overview
- Theophylline is an older drug that is approved to treat COPD. Theophylline is not widely prescribed anymore because newer therapies are more effective and have fewer side effects. Another downside to theophylline therapy is that the drug requires blood monitoring due to its narrow therapeutic index.
- Two studies that looked at the addition of theophylline to other COPD therapies are detailed below
- The TWICS trial enrolled 1578 adults with COPD who were being treated with an ICS and who had ≥ 2 exacerbations in the past year
Main inclusion criteria
- Age ≥ 40 years
- COPD diagnosis
- Receiving ICS therapy
- Smoking history ≥ 10 pack-years
- ≥ 2 exacerbations within 12 months
Main exclusion criteria
- Respiratory disease other than COPD
- Significant heart disease
- Taking drugs that interact with theophylline
Baseline characteristics
- Average age - 68 years
- Current smoker - 32%
- Receiving ICS+LABA+LAMA - 80%
- Mean FEV1 (% predicted) - 52%
- Average # of exacerbations in past year - 3.6
Randomized treatment groups
- Group 1 (788 patients): Theophylline 200 mg once or twice daily
- Group 2 (779 patients): Placebo
- Theophylline dosing was based on ideal body weight (IBW) and smoking status. Nonsmokers or smokers with IBW ≤ 60 kg took theophylline once daily. Smokers with IBW > 60 kg took theophylline twice daily.
Primary outcome: Number of COPD exacerbations requiring antibiotics, oral corticosteroids, or both during the 52-week treatment period as reported by the
participant
Results
Duration: 52 weeks | |||
Outcome | Theophylline | Placebo | Comparisons |
---|---|---|---|
Primary outcome | 2.24 | 2.23 | Diff 0.01, 95%CI [−0.19 to 0.21] |
COPD hospital admissions (average per patient) | 0.17 | 0.24 | Diff -0.07, 95%CI [−0.13 to -0.01] |
Mean FEV1 % predicted at 52 weeks | 51.5% | 52.1% | N/A |
|
Findings: Among adults with COPD at high risk of exacerbation treated with inhaled corticosteroids, the addition of low-dose theophylline, compared with placebo,
did not reduce the number COPD exacerbations over a 1-year period. The findings do not support the use of low-dose theophylline as adjunctive therapy to inhaled corticosteroids for
the prevention of COPD exacerbations.
- STUDY
- Design: Randomized controlled trial (N=943, length = 12 weeks) in patients with COPD
- Exposure: Theophylline vs Salmeterol 42 mcg twice daily vs Salmeterol+Theophylline. All patients underwent an initial 7 - 10 day period where theophylline was titrated to a blood level of 10 - 20 mcg/ml.
- Primary outcome: Mean change from baseline in the area under the FEV1 vs time curve during 12-hour serial pulmonary function testing on day 1 and week 12.
- Results:
- Primary outcome: The Salmeterol+Theophylline group was significantly better than the salmeterol and theophylline groups (p≤0.008)
- Mean change in predose FEV1 at 12 weeks: Salmeterol+Theophylline +160 ml, Salmeterol +70 ml, Theophylline +50 ml
- Findings: Patients with COPD may benefit from combination treatment with salmeterol plus theophylline, without a resulting increase in adverse events or other adverse sequelae.
- Professional recommendations
- The 2017 GOLD COPD guidelines state that theophylline exerts a small bronchodilator effect in stable COPD that is associated with modest symptomatic benefits
- Theophylline is not recommended unless other long-term treatment bronchodilators are unavailable or unaffordable
- See COPD review for more
- SIDE EFFECTS
- Overview
- Theophylline and caffeine are both methylxanthines, and they share many of the same side effects
- If theophylline is initiated slowly at recommended doses, its side effects are generally mild and transient
- If therapy is initiated too quickly, up to 50% of patients may experience side effects
- In chronic therapy, < 3% of children and < 10% of adults experience side effects when levels remain < 20 mcg/ml
- Common side effects
- Nausea
- Vomiting
- Headache
- Insomnia
- Less common side effects
- Diarrhea
- Irritability
- Restlessness
- Fine skeletal muscle tremors
- Transient diuresis
- Toxicity
- When theophylline levels rise above 20 mcg/ml, side effects become much more prevalent
- Theophylline toxicity can be lethal and steps should be taken immediately to lower levels
- The table below shows the prevalence of symptoms seen in theophylline toxicity. The data is from studies where theophylline levels rose above 30 mcg/ml during chronic dosing.
Symptoms of theophylline toxicity | |
---|---|
Symptom | Prevalence |
Sinus tachycardia | 60 - 100% |
Vomiting | 30 - 60% |
Hypokalemia | 44% |
Ventricular arrhythmias | up to 40% |
Premature ventricular contractions (PVCs) | 10 - 19% |
Nervousness | 21% |
Hyperglycemia | 18% |
Tremors | 16% |
Seizures | 5 - 14% |
Supraventricular tachycardia | 14% |
Diarrhea | 14% |
Atrial fib/flutter | 12% |
Disorientation | 11% |
Acid/base disturbance | 5 - 9% |
- CONTRAINDICATIONS
- Known hypersensitivity
- PRECAUTIONS
- Kidney disease
- Adults and children > 3 months of age: no dose adjustment necessary
- < 3 months of age: see neonates below
- Liver disease
- Clearance is decreased by ≥ 50% in patients with hepatic insufficiency
- Careful attention to dose reduction and frequent monitoring of serum theophylline concentrations are required
- Seizure disorders
- Theophylline may exacerbate seizure disorders. Use caution.
- Cardiac arrhythmias
- Theophylline may exacerbate cardiac arrhythmias. Use caution.
- Peptic ulcer disease
- Theophylline may exacerbate peptic ulcer disease. Use caution.
- Elderly
- Theophylline clearance is decreased by an average of 30% in healthy elderly adults (> 60 yrs) compared to healthy young adults
- There have been a few isolated reports of seizures at serum theophylline concentrations < 20 mcg/mL in elderly patients
- Careful attention to dose reduction and frequent monitoring of serum theophylline concentrations are required in elderly patients
- Neonates
- Renal excretion of unchanged theophylline in neonates amounts to about 50% of the dose compared to about 10% in children ≥ 3 months and adults
- Careful attention to dosage selection and monitoring of serum theophylline concentrations are required in pediatric patients
- Congestive heart failure
- Theophylline clearance is decreased by ≥ 50% in patients with CHF
- Careful attention to dose reduction and frequent monitoring of serum theophylline concentrations are required in patients with CHF
- Smokers (tobacco and THC)
- Tobacco and marijuana smoking appears to increase the clearance of theophylline by induction of metabolic pathways
- Theophylline clearance has been shown to increase by approximately 50% in young adult tobacco smokers and by approximately 80% in elderly tobacco smokers compared to non-smoking subjects
- Passive smoke exposure has also been shown to increase theophylline clearance by up to 50%
- Abstinence from tobacco smoking for one week causes a reduction of approximately 40% in theophylline clearance
- Careful attention to dose reduction and frequent monitoring of serum theophylline concentrations are required in patients who stop smoking
- Fever
- Fever can decrease the clearance of theophylline
- The magnitude and duration of the fever appear to be directly correlated to the degree of decrease of theophylline clearance
- A temperature of 39° C (102° F) for at least 24 hours is probably required to produce a clinically significant increase in serum theophylline concentrations
- Hypothyroidism
- Hypothyroidism may reduce theophylline clearance. Use caution.
- Neurologic diseases
- There have been a few isolated reports of seizures at serum theophylline concentrations < 20 mcg/mL in patients with an underlying neurological disease
- DRUG INTERACTIONS
- NOTE: Drug interactions presented here are NOT all-inclusive. Other interactions may exist. The interactions presented here are meant to encompass commonly prescribed medications and/or interactions that are well-documented. Always consult your physician or pharmacist before taking medications concurrently. CLICK HERE for more information on drug interactions.
- Drug interactions
- Because theophylline has a narrow therapeutic index, it has a long list of potentially significant drug interactions
- See the Theo-24 PI for a list of drug interactions
- Metabolism and clearance
- CYP1A2 - sensitive substrate
- CYP3A3 - substrate
- CYP2E1 - substrate
- DOSING
- Dosage forms
- Theo-24® extended-release capsule
- 100 mg
- 200 mg
- 300 mg
- 400 mg
- Generic/Cost: NO / > $100 a month
- Theophylline extended-release tablet (Theochron®)
- 100 mg
- 200 mg
- 300 mg
- 400 mg
- 600 mg
- Generic/Cost: YES / < $50 a month
- Solution, elixir (Elixophyllin®)
- 80 mg/15 ml
- Comes in 473 ml (16 oz) bottle
- Generic/Cost: YES / 473 ml is < $50
- Food effects
- Solution (Elixophyllin®): may take without regard to food
- Extended-release tablet (Theochron®): preferably taken with meals. Either way, take consistently with food or take consistently without food. Food increases absorption.
- Extended-release capsule (Theo-24®): take consistently with food or take consistently without food. Food increases absorption.
Theophylline Solution Dosing (Elixophyllin®) | |
---|---|
Children (1 - 15 years) < 45 kg without risk factors for impaired clearance✝ | |
Titration step | Dosing |
Step 1: Starting dose | 12 - 14 mg/kg/day up to a maximum of 300 mg/day divided every 4 - 6 hrs |
Step 2: After 3 days, if tolerated, increase dose to: | 16 mg/kg/day up to a maximum of 400 mg/day divided every 4 - 6 hrs |
Step 3: After 3 more days, if tolerated, increase dose to: | 20 mg/kg/day up to a maximum of 600 mg/day divided every 4 - 6 hrs |
Children > 45 kg and adults without risk factors for impaired clearance✝ | |
Titration step | Dosing |
Step 1: Starting dose | 300 mg/day divided every 6 - 8 hrs |
Step 2: After 3 days, if tolerated, increase dose to: | 400 mg/day divided every 6 - 8 hrs |
Step 3: After 3 more days, if tolerated, increase dose to: | 600 mg/day divided every 6 - 8 hrs |
Extended-release Tablet and Capsule Dosing (Theo-24®, Theochron®) | |
---|---|
Children (12 - 15 years) < 45 kg without risk factors for impaired clearance✝ | |
Titration step | Dosing |
Step 1: Starting dose | 12 - 14 mg/kg once daily up to a maximum of 300 mg/day* |
Step 2: After 3 days, if tolerated, increase dose to: | 16 mg/kg once daily up to a maximum of 400 mg/day* |
Step 3: After 3 more days, if tolerated and if needed, increase dose to: | 20 mg/kg once daily up to a maximum of 600 mg/day* |
Children > 45 kg and adults without risk factors for impaired clearance✝ | |
Titration step | Dosing |
Step 1: Starting dose | 300 - 400 mg once daily* |
Step 2: After 3 days, if tolerated, increase dose to: | 400 - 600 mg once daily* |
Step 3: After 3 more days, if tolerated and if needed, increase dose to: | As with all theophylline products, doses greater than 600 mg should be titrated according to blood level |
- Lab monitoring
- For most patients, steady state will be reached after 3 days (see pharmacokinetics below), so lab monitoring should occur at 3 day intervals during dose adjustments
- After an appropriate maintenance dose is determined, serum theophylline concentrations should be monitored at 6 month intervals for rapidly growing children and at yearly intervals for all others
- Dose adjustments are based on peak levels
- Peak levels (Theo-24® capsules): 12 hours after a dose at steady state
- Peak levels (Extended-release tablet): 12 hours after an evening dose or 9 hours after a morning dose at steady state
- Peak levels (Solution): 1 - 2 hours after a dose at steady state
- Dose adjustment recommendations for serum theophylline levels are presented in the table below
Peak level (mcg/ml) |
Dose adjustment |
---|---|
< 9.9 | If symptoms are not controlled and current dosage is tolerated, increase dose about 25%. Recheck serum concentration after three days for further dosage adjustment. |
10 - 14.9 | If symptoms are controlled and current dosage is tolerated, maintain dose and recheck serum concentration at 6-12 month intervals. If symptoms are not controlled and current dosage is tolerated consider adding additional medication(s) to treatment regimen. |
15 - 19.9 | Consider 10% decrease in dose to provide greater margin of safety even if current dosage is tolerated. |
20 - 24.9 | Decrease dose by 25% even if no adverse effects are present. Recheck serum concentration after 3 days to guide further dosage adjustment. |
25 - 30 | Skip next dose and decrease subsequent doses at least 25% even if no adverse effects are present. Recheck serum concentration after 3 days to guide further dosage adjustment. If symptomatic, consider whether overdosage treatment is indicated. |
> 30 | Treat overdose as indicated (see theophylline PI and contact poison control). If theophylline is subsequently resumed, decrease dose by at least 50% and recheck serum concentration after 3 days to guide further dosage adjustment. |
- Pharmacokinetics
- Theophylline pharmacokinetics vary widely between individuals
- Half-life (1 - 4 years): average 3.4 hr (range 1 - 6 hr)
- Half-life (6 - 17 years): average 3.7 hr (range 1.5 - 6 hr)
- Half-life (16 - 60 years): average 8.7 hr (range 6 - 13 hr)
- Half-life (≥ 60 years): average 9.8 hr (range 1.6 - 18 hr)
- Time to steady state (adults): average 40 hr (range 30 - 65 hr)
- Time to steady state (1 - 17 years): range 5 - 40 hr
- Reference: Theo-24® PI and Quest diagnostics®
- LONG-TERM SAFETY
- Theophylline was FDA-approved in 1985
- Theophylline is not widely prescribed anymore because it has modest efficacy, potentially serious side effects, requires laboratory monitoring, and has an extensive list of drug interactions
- BIBLIOGRAPHY
- 1 - Theo-24 PI
- 2 - Theophylline ER tablet PI
- 3 - Elixophyllin PI