The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Feeling like you had too much caffeine (nausea, vomiting, headache, inability to sleep)
Less Common Side Effects
- Abdominal pain or stomach irritation
- Feeling anxious, irritable, or restless
- Severe allergic reaction
- Abnormal heart rhythm or fast heart rate
- Diarrhea
- Dizziness
- Muscle tremors
- High uric acid levels
- Itchiness, rash, or hives
- Urinating more, or not being able to urinate
Source: DailyMed
The following Theophylline ER side effects have also been reported
Along with its needed effects, a medicine 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 or nurse immediately if any of the following side effects occur:
Incidence not known
Blurred vision
chest pain or discomfort
dizziness
fainting
fast, slow, or irregular heartbeat
headache
increase in urine volume
infection at the injection site
lightheadedness
pain or redness at the site of injection
pale skin at the site of injection
persistent vomiting
pounding or rapid pulse
rapid breathing
seizures
shakiness
shortness of breath
swelling of the lower legs or arms
tenderness, pain, swelling, warmth, skin discoloration, and prominent superficial veins over the affected area
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
Abdominal or stomach pain
confusion
confusion about identity, place, and time
dark-colored urine
decrease in frequency of urination
decreased urine
difficulty in passing urine (dribbling)
dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
fast, pounding, or irregular heartbeat or pulse
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
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 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:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
