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Fentanyl Related Somnolence

Official FDA Reports1,481
Social Media Events91
Active Ingredients
  • Fentanyl
Additional Terms for Somnolence
  • Fatigue
  • Sleepiness
  • Drowsiness
  • Groggy
  • Very Sleepy
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  This report is for all products sharing this active ingredient. For more details, please use our Workbench for research on individual brands like Duragesic-100.


The quarterly trend chart illustrates changing levels of adverse events over time. Results from both the FDA Adverse Event Database (AERS) and adverse events extracted from social media by Druginformer are plotted side-by-side for easy comparison.

List of Possible Side Effects Reported

Report Date Dosage Indication Outcome Country Gender Age Weight (lbs)

* DrugInformer calculates alarm using a proprietary algorithm. Alarm should not be taken as an ofiicial signal from the FDA or other regulatory entity.

Social Media Comments From Around the Web

The following are comments from users that experienced side effects while taking Milnacipran Hydrochloride


... months later, and NO NARCOTICS or pain medications, I can honestly say that the pain is really no different than when I was taking all medications and making me feel dopey, confused, drowsy and out of...

Source:" Fentanyl-Transdermal-Patch-review-13cb5

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Did the author experience somnolence while taking fentanyl?

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Side Effects: On the 4th day on the medication the patient who had been very responsive and alert was groggy , not alert and fell several times in attempts to go to the bathroom, something he had no p...

Source:" Duragesic (Fentanyl Transdermal)

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Side Effects: After 6-16 hours I became quite sleepy and tired. After a couple of hours of sleep, I awoke feeling as I usually do first thing in the morning. A couple of hours later the sleepiness ...

Source:" Duragesic (Fentanyl Transdermal)

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Tell us about your Experience with Fentanyl Related Somnolence

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Share Your Experience

Druginformer Identified Side Effects: Constipation, Drug dependence, Euphoric mood, Somnolence

Posted By Anonymous in askapatient.com on June 27, 2014 @ 12:00 am

Side Effects: Constipation, drowsiness. Note: these do not make me high, though I am sure that my body is physically addicted to them - I have been taking them for 14 years now. The Fen...

Druginformer Identified Side Effects: Fatigue, Restlessness, Somnolence

Posted By Anonymous in drugs.com on November 9, 2013 @ 12:00 am

... having some real bad side affects from the drug. After about 24-36 hours of putting on the patch I would start to get pain, agitation,sick feeling all over my body, fatigue, restlessness, very tired, ...

Druginformer Identified Side Effects: Disturbance in attention, Somnolence, Withdrawal syndrome

Posted By Anonymous in askapatient.com on May 9, 2013 @ 12:00 am

Has helped but have horrendous brain fog. Tiredness which is threatening my job security. I had to choose this drug, morphine continuous release,, or methadone for my pain relief after m...

Druginformer Identified Side Effects: Somnolence

Posted By mommazitta in fdb.rxlist.com on February 10, 2013 @ 12:00 am

... patch was the 3rd opiod pain killer prescribed to me, and of them all, the pain was minimal, but wow,I'm not sure if its normal but the Sweating and Fatigue were uncomfotably frequent...Im weaning off...

Druginformer Identified Side Effects: Back pain, Headache, Chills, Hyperhidrosis, Somnolence

Posted By Anonymous in drugs.com on May 23, 2012 @ 12:00 am

... loss and decay, this just after spending $2000 to get my teeth put into shape. I go from hot flashes and drenching sweats to chills every 10 to 15 minutes. I have severe backache, headache and urine...

Druginformer Identified Side Effects: Thought withdrawal, Somnolence

Posted By Anonymous in askapatient.com on March 19, 2012 @ 12:00 am

... no creepy withdrawals and they work well. Good luck to everybody :) hope your pain becomes better n easier. The side effects are some tiredness and feeling a little checked out sometimes. ...

Druginformer Identified Side Effects: Nausea, Vomiting, Somnolence

Posted By Anonymous in askapatient.com on November 25, 2011 @ 12:00 am

Side Effects: Nausea, vomiting, tiredness I tried over 60 various medications to control the intense chronic pain caused by my generalized internal chronic RSD (Reflex Sympathetic Dystrophy...

Druginformer Identified Side Effects: Euphoric mood, Drug ineffective, Somnolence

Posted By Anonymous in drugs.com on November 1, 2011 @ 12:00 am

My Pain is completely alleviated with this medication when in normal use. I am on a 3 day schedule in changing the patches. I did try to go on a 2 day schedule as well, but then I experience too man...

Druginformer Identified Side Effects: Constipation, Somnolence

Posted By MRSDJMCW in drugs.com on October 30, 2011 @ 12:00 am

... raised it to 150 over the course of a few years. Currently I am able to control my pain to about a "4" out of 10, by adding Oxycontin for breakthrough pain. Drowsiness and constipation are the most an...

Druginformer Identified Side Effects: Hypersomnia, Exostosis, Somnolence

Posted By painsux in fdb.rxlist.com on May 31, 2011 @ 12:00 am

... strips to keep it in place. After using this for almost 6 months, I have gone from the lowest dose to almost 100mcg. I find myself sleeping 12-17 hours a day, falling asleep while driving, my pa...

* Warning: The facts and figures contained in these reports are accurate to the best of our capability; however, our metrics are only meant to augment your medical knowledge, and should never be used as the sole basis for selecting a new medication. As with any medical decision, be sure to work with your doctor to ensure the best choices are made for your condition.

* About FAERS: The FDA Adverse Event Reporting System (FAERS) is used by FDA for activities such as looking for new safety concerns that might be related to a marketed product, evaluating a manufacturer's compliance to reporting regulations and responding to outside requests for information. Reporting of adverse events is a voluntary process, and not every report is sent to FDA and entered into FAERS. The FAERS database may contain duplicate reports, the report quality is variable, and many factors may influence reporting (e.g., media attention, length of time a drug is marketed, market share). For these reasons, FAERS case reports cannot be used to calculate incidence or estimates of risk for a particular product or compare risks between products.