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
- Nausea (45%)
- Weakness (38%)
- Vomiting (31%)
- Shortness of breath (22%)
- Constipation (20%)
- Headache (20%)
- Dizziness (16%)
- Anxiety (15%)
- Sleepiness (15%)
Less Common Side Effects
- Accidental injury
- Stiff muscles
- Confusion
- Depression
- Trouble sleeping
- Dry mouth
- Abnormal walking
- Nervousness
- Rash
- Sweating
Fentanyl Citrate serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Overdose: not responding to sound or touch, slowed breathing, sleepiness, muscle weakness, small pupils, cold or clammy skin, slow heart rate, coma
- Serious allergic reaction: hives, shortness of breath, chest tightness, swelling of lips, tongue, face, or eyes
- Slowed breathing
- Withdrawal in newborn babies: irritability, overactivity, abnormal sleeping pattern, excessive or high-pitched crying, body shaking (tremor), vomiting, diarrhea, unable to gain weight, breathing problems, fever, sweating, seizures
- Adrenal insufficiency (low cortisol levels): nausea, vomiting, stomach pain, low appetite, tiredness, weakness, dizziness, low blood pressure
- Withdrawal: restlessness, runny nose, yawning, sweating, chills, widened pupils, irritability, anxiety, suicidal thoughts
Source: DailyMed
The following Fentanyl Citrate 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
Black, tarry stools
blurred vision
confusion
convulsions
decreased urine
difficult or labored breathing
dizziness
fainting
fever or chills
increased thirst
irregular heartbeat
lightheadedness
loss of appetite
lower back or side pain
mood changes
muscle pain or cramps
nausea or vomiting
nervousness
numbness or tingling in the hands, feet, or lips
painful or difficult urination
pale skin
pounding in the ears
rapid breathing
sunken eyes
swelling of the hands, ankles, feet, or lower legs
tightness in the chest
troubled breathing with exertion
ulcers, sores, or white spots in the mouth
unusual bleeding or bruising
unusual tiredness or weakness
wrinkled skin
Less common
Abdominal or stomach pain
change in walking and balance
clumsiness or unsteadiness
decreased awareness or responsiveness
decreased frequency of urination
headache
muscle twitching or jerking
pounding in the ears
rhythmic movement of the muscles
seeing, hearing, or feeling things that are not there
seizures
severe constipation
severe sleepiness
shakiness in the legs, arms, hands, or feet
slow or fast heartbeat
thinking abnormalities
trembling or shaking of the hands or feet
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
Extremely shallow or slow breathing
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
Back pain
difficulty having a bowel movement (stool)
difficulty with moving
discouragement
feeling sad or empty
irritability
lack or loss of strength
loss of interest or pleasure
muscle stiffness
pain in the joints
sleepiness or unusual drowsiness
tiredness
trouble concentrating
trouble sleeping
Less common
Changes in vision
excessive muscle tone
feeling of constant movement of self or surroundings
feeling of warmth or heat
flushing or redness of the skin, especially on the face and neck
irritation, pain, or sores at the site of application
itching skin
muscle tension or tightness
rash
sensation of spinning
sweating
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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