What Are the Most Common Theophylline Side Effects?

Theophylline is a drug that is recommended for humans and animals with breathing difficulties. Although the drug is considered safe when used as prescribed, some people can experience side effects. The most common theophylline side effects are a result of the drug's close relationship to caffeine and include restlessness, jitters, insomnia and a racing heartbeat. Theophylline can also cause upset stomach, increased urination, irritability and headaches.

One of the most effective treatments for asthma, chronic bronchitis, emphysema and other lung-based breathing problems in humans and animals is the drug theophylline. It works by relaxing air passages in the lungs to increase airflow. The drug can help alleviate wheezing and shortness of breath, but does not cure the underlying ailment.

Ordinarily, theophylline is considered safe when used as directed. Like many drugs, however, taking theophylline can cause side effects in some people. The most common theophylline side effects that a person can experience are considered mild, as compared to other types of prescription drugs. Theophylline is related to caffeine, which can also be used to treat breathing difficulties, but it is used instead of caffeine because it has less of a likelihood of causing side effects.

The most common theophylline side effects are the same sorts of reactions that a person would experience as a result of a negative reaction to the caffeine in coffee, tea or chocolate. These include restlessness, jitters, insomnia and headaches. Theophylline can also cause a person's heart to race, resulting in irregular heartbeats. The drug is also a diuretic, so it can cause increased urination in some people. Other side effects include upset stomach, irritability and diarrhea.

Theophylline side effects can be exacerbated by certain interactions. For example, additional intake of caffeine can multiply the likelihood and severity of side effects. Doctors tend to recommend that people taking theophylline avoid foods and drinks that contain high levels of caffeine. The drug is also metabolized through the liver. If it is taken in conjunction with other drugs that are metabolized in the same way, the chemical composition of the drug can change, causing dangerous side effects.

Blood tests are used to monitor the levels of theophylline in humans. This procedure helps control theophylline side effects because certain effects can be avoided by decreasing the drug's dosage or increasing it gradually. Although blood tests are an effective way to mange side effects in humans, the procedure is not similarly effective for animals on the drug.