Theophylline

Commonly reported side effects of theophylline include: acid-base imbalance. See below for a comprehensive list of adverse effects.

Applies to theophylline: oral capsule extended release 24 hr, oral elixir, oral solution, oral tablet extended release, oral tablet extended release 12 hr, oral tablet extended release 24 hr

Other dosage forms:

• intravenous solution

Along with its needed effects, theophylline may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking theophylline:

Incidence not known

• Chest pain or discomfort
• dizziness
• fainting
• fast, slow, or irregular heartbeat
• increase in urine volume
• lightheadedness
• persistent vomiting
• pounding or rapid pulse
• seizures
• shakiness

Get emergency help immediately if any of the following symptoms of overdose occur while taking theophylline:

Symptoms of overdose

• Abdominal or stomach pain
• blurred vision
• confusion
• confusion about identity, place, and time
• dark-colored urine
• decrease in frequency of urination
• decreased urine
• diarrhea
• difficulty in passing urine (dribbling)
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• dry mouth
• fast, pounding, or irregular heartbeat or pulse
• fever
• increased thirst
• irregular heartbeat
• loss of appetite
• mood changes
• muscle cramps or spasms
• muscle pain or stiffness
• nausea or vomiting
• nervousness
• numbness or tingling in the hands, feet, or lips
• pain or discomfort in the arms, jaw, back, or neck
• painful urination
• shakiness in the legs, arms, hands, or feet
• shortness of breath
• sweating
• unusual tiredness or weakness
• vomiting of blood or material that looks like coffee grounds

Some side effects of theophylline may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

• Headache
• irritability
• restlessness
• sleeplessness
• trouble sleeping
• unable to sleep

Applies to theophylline: compounding powder, intravenous solution, oral capsule, oral capsule extended release, oral elixir, oral solution, oral syrup, oral tablet, oral tablet extended release

Adverse events are generally mild when theophylline levels are under 20 mcg/mL; the most common adverse events were caffeine-like adverse effects like nausea, vomiting, headache, and insomnia.

When theophylline concentrations exceed 20 mcg/mL, many adverse effects may occur, including persistent vomiting, cardiac arrhythmias, and intractable seizures, which may be fatal.

Very common (10% or more): Sinus tachycardia (up to 100% in acute overdose, up to 100% with chronic overdose), ventricular arrhythmias with hemodynamic instability (14% in acute overdose, 40% with chronic overdose), other supraventricular tachycardias (21% in acute overdose, 14% with chronic overdose), ventricular premature beats (21% in acute overdose, 19% with chronic overdose), hypotension/shock (21% in acute overdose, 8% with chronic overdose), atrial fibrillation or flutter (1% in acute overdose, 12% with chronic overdose)

Common (1% to 10%): Multifocal atrial tachycardia (2% with chronic overdose)

Frequency not reported: Cardiac arrhythmias (at serum concentrations over 20 mcg/mL), multifocal atrial tachycardia and flutter (at serum concentrations 15 mcg/mL and over in hypoxia secondary to COPD patients)

-A few seizures have been reported in patients with underlying neurological disease or in elderly patients with serum theophylline under 20 mcg/mL.

-Seizures in elderly patients with serum theophylline under 20 mcg/mL may be due to decreased protein binding causing higher unbound (pharmacologically active) theophylline levels.

-Seizures in patients with serum theophylline under 20 mcg/mL were generally milder (than those from overdose) such as being transient, not requiring anticonvulsants, and no neurological residuals.

-Consider the possibility of non-convulsive status epilepticus in patients with abnormal central nervous system function and theophylline use.

Very common (10% or more): Vomiting (93% in acute overdose, 61% with chronic overdose), abdominal pain (21% in acute overdose, 12% with chronic overdose), diarrhea (14% with chronic overdose)

Common (1% to 10%): Hematemesis (2% with chronic overdose)

Frequency not reported: Nausea, vomiting, persistent vomiting (at serum concentrations over 20 mcg/mL), diarrhea

Very common (10% or more): Tremors (38% in acute overdose, 16% with chronic overdose), seizures (14% in acute overdose, 14% with chronic overdose)

Frequency not reported: Headache, intractable seizures (at serum concentrations over 20 mcg/mL), seizures

Very common (10% or more): Hyperglycemia (98% in acute overdose, 18% with chronic overdose), hypokalemia (85% in acute overdose, 44% with chronic overdose), acid/base disturbance (34% in acute overdose, 9% with chronic overdose)

Frequency not reported: Hypercalcemia (in a hyperthyroid patient), hypervolemia

Very common (10% or more): Nervousness (64% in acute overdose, 21% with chronic overdose), disorientation (7% in acute overdose, 12% with chronic overdose)

Frequency not reported: Insomnia, irritability, restlessness

Uncommon (0.1% to 1%): Rhabdomyolysis (7% in acute overdose)

Frequency not reported: Fine skeletal muscle tremors

Very common (10% or more): Death (21% in acute overdose, 10% with chronic overdose)

Frequency not reported: Febrile response

Frequency not reported: Transient diuresis

Frequency not reported: Infection at the site of injection, venous thrombosis or phlebitis extending from the site of injection, extravasation