Fentanyl (Systemic)

Brand Names : Actiq

Side Effects of This Medicine

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 as soon as possible if any of the following side effects occur:

More common

Dizziness, feeling faint, lightheadedness, unusual tiredness or weakness; shortness of breath

Less common

Anxiety; confusion; decrease in urine volume; decreased frequency of urination; drowsiness; false sense of well-being; nervousness; seeing, hearing, or feeling things that are not there

Symptoms of overdose

Cold, clammy skin; convulsions (seizures); feeling faint; pinpoint pupils of the eyes; severe dizziness, drowsiness, nervousness, restlessness, or weakness; slow or troubled breathing

Other 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. However, check with your doctor if any of the following side effects continue or are bothersome:

More common

Constipation; dry mouth; nausea and/or vomiting

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this period of time check with your doctor if you notice any of the following side effects:

Diarrhea; nausea and/or vomiting; restlessness or irritability; speech disorder; stomach cramps; trouble in sleeping; weakness

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.