Theophylline is a bronchodilator that relaxes the smooth muscle around the bronchial tubes allowing for more air to move freely though the tubes. Theophylline is metabolized by the liver and excreted by the kidneys. It can be measured in the blood. Occasional blood tests need to be done to maintain therapeutic levels.

Theophylline has been used to treat asthma for over fifty years. There are now new forms of theophylline that are long acting and only need to be taken once or twice daily.

Brand Names

Xanthines (Bronchodilators)
Aerolate -TD capsules, liquid
Quibron-T – Tablets, SA tablets (see also combinations)
Respbid – SR tablets
Slo-bid – ER capsules
Slo-phylline – ER capsules
T-Phyl – CR tablets
Theo-24 – ER capsules
Theo-Dur Sprinkle – SA capsules
Theo-X – Tablets
Theolair – Tablets, SR tablets, liquid
Uniphyl – CR tablets
Lufyllin – Tablets, injection, syrup
Choledyl -DR tablets, SA tablets
*Similar to theophylline, but rarely used any more
**Oxytriphylline is a choline salt of theophylline, and 400 mgs of it is equivalent to 254 mgs of theophylline.

Drug Action

Theophylline relaxes bronchial smooth muscles. Theophylline can also improve ciliary activity and diaphragmatic contractibility.

Side Effects

Theophylline is well tolerated by most people. Side effects may occur when theophylline is first introduced into your system, Theophylline can increase urination, increase acid in the stomach, increase the heart rate, stimulate the nervous system and worsen gastric reflux. These side effects can cause the following symptoms:

  • Nausea
  • Heartburn
  • Restlessness
  • Insomnia
  • Tremors
  • Frequent urination
  • Muscle spasms
  • Anxiety
  • Irritability
  • Headache

Toxic Side Effects

These side effects may occur if the amount of medicine in the blood reaches toxic levels. This can occur if you have a viral infection or a drug incompatibility. Notify your doctor if you have symptoms of nausea and vomiting or severe headaches. Seizures can occur with very high levels of theophylline. Never take an extra dose of theophylline without your doctor’s permission.

Available Forms

Theophylline preparations come in liquids, tablets or capsules. Liquids are short-acting and take 30 to 60 minutes to begin working. Tablets can be short-acting or long-acting. Long-acting tablets take 1 to 1/5 hours to begin working. Some once-a-day preparations don’t begin to work fully for 4 to 6 hours.

Capsules can be swallowed or opened and the beads sprinkled onto foods. It is important not to chew the beads as this will cause faster absorption. Capsules are long-acting. Intravenous aminophylline or theophylline can be given during hospitalization.

Additional Comments

Theophylline should be taken in a regularly scheduled basis. If a dose is missed, the blood levels may decrease which may cause an increase in asthma symptoms. If an extra dose is taken the blood level may increase, causing side effects.

Uniphyl and Unidur are long-acting bronchodilators that work well for those individuals who have nighttime symptoms. They are best taken between 7 and 8 PM. This will allow the peak effect to occur when it is most necessary.

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