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
- Dizziness (19%)
- Vision changes (16%)
- Shortness of breath (10%)
- Headache (10%)
- Nausea (9%)
- Tiredness (8%)
- Heart pounding (6%)
- Chest pain (5%)
- Weakness (5%)
- Tremor (5%)
- Constipation (4%)
- Swelling in the arms and legs (4%)
- Stomach pain (3%)
Less Common Side Effects
- Vomiting
- Diarrhea
- Poor appetite
- Fever
- Rash
- Double vision
- Tingling or numbness
- Sweating
- Fainting
- Sleepiness
- Ringing in the ears
- Anxiety
- Trouble sleeping
Flecainide serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Abnormal heart rhythm: chest pain, chest discomfort, palpitations, shortness of breath, fatigue, weakness, sweating
- Heart failure: shortness of breath, swelling, sudden weight gain, coughing or wheezing, fast heart rate
Source: DailyMed
The following Flecainide 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 immediately if any of the following side effects occur:
More common
Difficult or labored breathing
dizziness, fainting, or lightheadedness
fast, irregular, pounding, or racing heartbeat or pulse
shortness of breath
tightness in the chest
Less common
Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
fainting
feeling of warmth
increased sweating
partial or slight paralysis
redness of the face, neck, arms, and occasionally, upper chest
shakiness and unsteady walk
shakiness in the legs, arms, hands, or feet
swelling of the feet or lower legs
trembling or shaking of the hands or feet
unsteadiness, trembling, or other problems with muscle control or coordination
Rare
Arm, back, or jaw pain
black, tarry stools
bleeding gums
blood in the urine or stools
blurred vision
chest discomfort
chest tightness or heaviness
chills
confusion
convulsions
decrease in the frequency of urination
decrease in urine volume
difficulty in passing urine (dribbling)
difficulty with breathing
dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
general feeling of discomfort or illness
headache
increased volume of pale, dilute urine
nervousness
noisy breathing
painful or difficult urination
pinpoint red spots on the skin
pounding in the ears
sensation of pins and needles
slow or fast heartbeat
sores, ulcers, or white spots on the lips or in the mouth
stabbing pain
sweating
swollen glands
thickening of bronchial secretions
troubled breathing
unusual bleeding or bruising
unusual tiredness or weakness
yellow eyes or skin
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:
More common
Blurred vision or seeing spots
Less common
Abdominal or stomach pain
acid or sour stomach
anxiety or mental depression
belching
continuing ringing or buzzing or other unexplained noise in the ears
feeling of constant movement of self or surroundings
general feeling of discomfort or illness
hearing loss
indigestion
lack or loss of strength
loss of appetite
sensation of spinning
sleepiness or unusual drowsiness
skin rash
stomach discomfort, upset, or pain
trouble with sleeping
unable to sleep
Rare
Bloated
change in color vision
change in taste
cracks in the skin
decreased awareness or responsiveness
decreased interest in sexual intercourse
difficulty seeing at night
difficulty with moving
excess air or gas in the stomach or intestines
eye pain or irritation
false or unusual sense of well-being
feeling of unreality
full feeling
hair loss or thinning of the hair
hives or welts
inability to have or keep an erection
increased sensitivity of the eyes to sunlight
itching skin
joint pain
lack of feeling or emotion
loss in sexual ability, desire, drive, or performance
loss of heat from the body
loss of memory
muscle aching or cramping
muscle pain or stiffness
passing gas
problems with memory
red, swollen skin
sense of detachment from self or body
severe sleepiness
swollen joints
swollen lips, mouth, or tongue
uncaring uncontrolled eye movements
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.
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