Examples
|
| aminophylline | |
| theophylline | Elixophyllin, Theo-24 |
These medicines are available in pill, liquid, injection,
or suppository form. One medicine may be available in multiple forms. Your
doctor will help you decide which type is best for you.
How It Works
The actions of methylxanthines are not
completely known.
Theophylline may:
- Slightly relax the airways in the lungs (bronchodilator).
- Improve breathing by
increasing the strength of the
diaphragm (if it is weakened) and by stimulating the
breathing control centers in the brain.
- Make it easier to get
mucus out of the lungs.
Why It Is Used
Because of their side effects,
methylxanthines are not considered first-choice medicines to treat
chronic obstructive pulmonary disease (COPD). They are
prescribed most often for people with COPD who:
- Still have major difficulty breathing despite
using both an inhaled beta2-agonist and an inhaled
anticholinergic.
- Have persistent nighttime
symptoms.
- Have frequent, rapid, and sometimes sudden
increase in shortness of breath (COPD exacerbation).
How Well It Works
A few studies have noted that,
compared to a
placebo, theophylline provides a small improvement in
lung function as measured by tests (spirometry) in
people who have stable COPD.2
In a COPD
exacerbation, methylxanthines, compared to a placebo, provide a small
improvement in lung function as measured by spirometry.1
In general, research shows that the small
improvement in lung function does not justify the severe side effects for most
people who have COPD. In most cases, newer and safer medicines
have replaced methylxanthines for treatment of people who have COPD.
Side Effects
The side effects of methylxanthines are
described as being similar to drinking too much caffeine, and they
include:
- Stomach
upset.
- Heartburn.
- Trouble sleeping
(insomnia).
- Headache.
- Nervousness or
irritability.
- Rapid heart rate (tachycardia).
- Rapid
breathing (tachypnea).
People taking the medicine may be able to reduce these side
effects by avoiding caffeine.
Serious (toxic) side effects are
seen in some people. These side effects include:
- Nausea and
vomiting.
- Seizures.
- Low blood
sugar.
- Irregular heartbeat (arrhythmia).
The difference between a dose of theophylline that helps
improve symptoms and a dangerous dose (one that causes serious side effects) is
small. Theophylline also has significant interactions with other prescribed
medicines, which can make it less effective and potentially life-threatening.
Theophylline relaxes the
esophagus near the opening into the stomach. This may
result in
heartburn (acid reflux) if stomach acid moves up into
the esophagus. Acid reflux may make airway obstruction worse (making breathing
more difficult), particularly in people with
asthma. For more information, see the topic
Gastroesophageal Reflux Disease (GERD).
See Drug Reference for a
full list of side effects. (Drug Reference is not available in all
systems.)
What To Think About
Other medicines may be a better
choice than methylxanthines for treating COPD, because the dose needed to
improve symptoms is so close to a dose that causes serious side effects.
Theophylline interacts with many different types of medicines,
such as antibiotics, antacids, birth control pills, and those used for
seizures. Ask your doctor or pharmacist if a new
medicine will affect how much theophylline you take.
Different
brands of theophylline get into the bloodstream at different rates. So you
always should use the same generic or brand-name medicine.
Because
medicines and illnesses can affect how quickly theophylline is cleared from the
body, the amount of theophylline in the blood must be measured regularly to be
certain it remains at a safe level.
Smoking increases how quickly
theophylline is cleared from the body, so a person with COPD who continues to
smoke may need larger doses of the medicine.
People taking
theophylline should avoid caffeine-containing beverages. These may make
theophylline's side effects worse, especially jittery nerves and
headaches.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
References
Citations
- Barr RG, et al. (2003). Methylxanthines for
exacerbations of chronic obstructive pulmonary disease: Meta-analysis of
randomised trials. BMJ, 327: 643–648.
- Kerstjens H, et al. (2005). Chronic
obstructive pulmonary disease. Clinical Evidence (13):
1923-1947.
Credits
| By | Healthwise Staff |
|---|
| Primary Medical Reviewer | Caroline S. Rhoads, MD - Internal Medicine |
|---|
| Specialist Medical Reviewer | Ken Y. Yoneda, MD - Pulmonology |
|---|
| Last Revised | May 4, 2010 |
|---|
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