How Long Does Fentanyl Stay in Your System?

Powerful Synthetic Opioid Carries Risks If Not Used as Prescribed

Fentanyl is a synthetic opioid analgesic. Oral applications are mostly used for adult cancer patients who are already taking another pain medication but have sudden episodes of pain that break through their regular pain treatment. Transdermal patches are used for acute post-surgical pain or round-the-clock pain medication for patients who will need pain relief for a long time and can't be treated with other medication. Brand names for oral applications of fentanyl include Abstral, Actiq, Fentora, and Onsolis, which are lozenges, films, and tablets. Fentanyl transdermal patches include brand names Duragesic and Ionsys.

Fentanyl use is on the rise, intentionally and otherwise. In 2017, 28,400 people died from overdoses involving synthetic opioids other than methadone, according to the CDC. The CDC goes on to cite the National Center for Health Statistics, stating that 29% of all drug overdose deaths in 2016 mentioned fentanyl, a 1045% increase from 2012. Fentanyl is 50 to 100 times more potent than morphine. If you aren't sure how much you are taking, it can be very easy to overdose. The average lethal dose of fentanyl is only 2 mg. New fentanyl analogs have also started to be found in use that are more potent than fentanyl. Fentanyl is not tested for on standard drug tests but can be tested for specifically.

How Long Does It Take to Feel Effects?

Fentanyl is prescribed to pain patients as a lozenge or in the form of a transdermal patch. The patches take several hours to take effect, while the oral applications work faster. Each type of patch and oral application interacts differently in the body and it can be dangerous to switch one for another unless directed by your doctor. Fentanyl is sometimes prescribed to patients already taking other opioid medications, in which case the risk of overdose is greater.

It is critical to discuss the use of any other medications, supplements, and alcohol with your doctor if you are taking fentanyl. Many different drugs and substances can lead to dangerous interactions while you still have fentanyl in your system. You can look up the Medication Guide on the FDA website for the specific drug you are taking to see the precautions for that medication.

You must not drink alcohol or have alcohol of any kind while using fentanyl or you risk a serious reaction that could be fatal.

According to one study, people taking fentanyl outside of a prescription often obtain it from transdermal patch diversion, mixed up in oxycodone-, hydrocodone- or alprazolam-containing tablets, or mixed in with heroin or cocaine for injection or insufflation. Injecting or snorting fentanyl causes the high to come on faster than the patches.

How Long Does Fentanyl Last?

A 100 microgram patch delivers 100 micrograms of fentanyl per hour, containing 168 hours worth of fentanyl. That is the equivalent of 1.68 grams of IV morphine and is an extremely large dose. Fentanyl is measured in micrograms, not milligrams. This drug is so potent it is highly recommended to not deviate from your prescribed dose, as even a small increase can dramatically increase the dose and prolong the effects. This is also why it is so easy to overdose, especially if you did not know that fentanyl was present in the drugs you were taking. Fentanyl also interacts with Xanax, Klonopin, and Ativan, which amplify the depressing effects on the central nervous system.

It is important to know how long fentanyl remains in the system to avoid possible accidental overdose. Doctors who prescribe fentanyl and the pharmacies that dispense it have to take special training to help reduce the risk to patients. After you are instructed about the prescription, you'll have to sign that you understand these risks. Typically patients have only prescribed fentanyl who already have a tolerance to other opiates, as even the lowest dose transdermal patch taken as prescribed contains enough for someone without a tolerance to overdose.

Factors That Affect Detection Time

Fentanyl can be detected using urine, hair, and blood tests. You can test positive for fentanyl on a urine test between one and three days after the last time you used it. According to one study, Norfentanyl, a metabolite created in the process of the body breaking down fentanyl, can be detected for up to four days after last use. Fentanyl can show up on a blood test between 5 and 48 hours after the last use. Hair tests are less commonly used by employers but can detect fentanyl for up to 3 months after last use. Drug tests commonly used to detect fentanyl typically employ mass spectrometry, which is also used to test the contents of drug samples by drug checking services.

One important thing to note is that the presence of Benadryl can trigger a false positive for fentanyl using these machines. This calls into question a lot of the prevailing data around how much fentanyl is in circulation. It also means you should let your testing agency know if you have recently taken Benadryl if they are going to be testing you for opiates. If you have been prescribed fentanyl and have to take a urine drug screen, it is also wise to disclose this to the testing lab. Fentanyl does not show up as positive on typical urine drug screening panels, but it can be detected by specific tests for the substance.

How to Get Fentanyl Out of Your System

How long fentanyl is present in the body depends on whether it was absorbed through the skin, absorbed through the mouth, or taken intravenously. It will also vary depending on a person's size, metabolism, hydration, and many other factors. It can take four days for fentanyl from lozenges or patches to be eliminated in the urine. None of these factors substantially impact how long a person has to stop using before a drug test in order to test negative.

You may be wanting to get fentanyl out of your system because you feel you have taken too many opiates and you do not want to be at risk for a respiratory arrest. While naloxone will not actually remove fentanyl from your system, administering it will block the opiate receptors in the body, causing the user to go into withdrawal. This is unpleasant but definitely preferable to an overdose.

If you are frequently using opiates, it's a good idea to pick up some naloxone from your state health agency or local pharmacy and get trained on how to use it. Naloxone is hard to self-administer, as many times when there is a real need for it, the person has become unresponsive. Tell a trusted friend trained in naloxone you are going to be using and ask them to get trained to use it. With the help of a support system, you will be able to stop the effects of fentanyl on the body when you need to. Be careful not to take any more opiates after that, even to curb withdrawal effects. The initial dose of opiates is still in the body and taking more puts you at risk for another overdose.

Symptoms of Overdose

Fentanyl can have dangerous cross-reactions with many other drugs and alcohol, including serious harm or death. The following are symptoms of an overdose from an opiate such as fentanyl:

  • Fingernails and lips turn blue or purplish black
  • Pulse (heartbeat) is slow, erratic, or not there at all
  • Non-responsive to outside stimulus
  • Awake, without the ability to speak
  • Loss of consciousness
  • Very slow, shallow, erratic, or stopped breathing
  • The skin of darker-skinned people looks grayish or ashen. The skin tone of lighter-skinned people looks bluish purple
  • Vomiting
  • Making a snore-like gurgling noise or "death rattle", choking sounds
  • Body is limp
  • Face is pale or clammy

An overdose emergency should be treated immediately with naloxone. Naloxone is available in many pharmacies and from your local health department. If many people in your area are using opiates or drugs purchased illegally that may have been mixed with fentanyl, it is a good idea to start carrying naloxone. You could save a life!

Getting Help

Opiate use disorder is treatable and not something to keep to yourself. For many people, it is not the opiate use disorder that kills them, it is keeping it a secret and using it in secret. If you are not in a position to stop using or to get into a treatment program, make sure to employ harm reduction methods, like knowing your dose, testing your drugs, pursuing a safe supply where possible (seek out local safe consumption facilities and syringe exchanges where you can be supervised by a professional), and letting a loved one know you are going to be using who carries and knows how to use naloxone.

Treatment options for opiate use disorder include medication-assisted tapering with substances such as buprenorphine or methadone, harm reduction psychotherapy, and programs designed to help get you off of opiates in a sustainable way. If you have chronic pain and are worried about stopping the medication, your health provider can work with you to get access to pain-relief that is less of a problem for your substance use disorder. Dependency on fentanyl or other opiates is nothing to be ashamed of. Please let someone you trust know and seek support.

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