Fentanyl

This substance is extraordinarily potent (i.e. active in the microgram range). For this reason, it should be handled with extreme care and never be eyeballed. Fentanyl can also be fatal when combined with depressants such as opiates, benzodiazepines, barbiturates, gabapentinoids, thienodiazepines or other GABAergic substances. It is strongly encouraged to wear gloves while handling, use volumetric dosing combined with a milligram scale, and to not consume either moderate or heavy dosages of other depressants in combination with this drug.

Fentanyl
Chemical Nomenclature
Common names	Fentanyl, fentanil, Sublimaze, Actiq, Durogesic, Duragesic, Fentora, Matrifen, Haldid, Onsolis, Instanyl, Abstral, Lazanda
Systematic name	N-(1-(2-Phenylethyl)-4-piperidinyl)-N-phenylpropanamide
Class Membership
Psychoactive class	Opioid
Chemical class	Piperidine
Routes of Administration
WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section. ⇣ Sublingual Dosage Bioavailability 50% Threshold 5 - 10 μg Light 10 - 25 μg Common 25 - 50 μg Strong 50 - 75 μg Heavy 75 μg + Duration Total 1 - 4 hours Onset 15 - 30 minutes ⇣ Insufflated Dosage Bioavailability 89% Threshold 5 - 10 μg Light 10 - 25 μg Common 25 - 50 μg Strong 50 - 75 μg Heavy 75 μg + Duration Total 1 - 4 hours Onset 15 - 30 minutes ⇣ Transdermal Dosage Bioavailability 92% Threshold 5 - 12 μg Light 12 - 25 μg Common 25 - 50 μg Strong 50 - 100 μg Heavy 100 μg + Duration Total 48 - 72 hours Onset 2 - 4 hours DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.
Interactions
Stimulants
MAOIs
Nitrous
PCP
Alcohol
Benzodiazepines
DXM
GHB
GBL
Ketamine
MXE
Tramadol
Grapefruit
MAOIs
Serotonin releasers
SSRIs
5-HTP

Summary sheet: Fentanyl

Fentanyl (also known as fentanil and brand names Sublimaze, Actiq, Durogesic, Duragesic, Fentora, Matrifen, Haldid, Onsolis, Instanyl, Abstral, Lazanda and others) is a potent synthetic piperidine opioid analgesic with a rapid onset and short duration of action. It is a strong agonist at the μ-opioid receptors and approximately 40 to 50 times more potent than pharmaceutical grade (100% pure) heroin and roughly 80 to 100 times more potent than morphine. The subjective effects of fentanyl are similar to those of heroin, with the exception that many users report a noticeably less euphoric "high" associated with the drug and stronger respiratory depression, sedation and pain relief.

A wide range of medical fentanyl preparations are available, including transdermal skin patches, lollipops, buccal tablets or patches, nasal sprays and inhalers.

Chemistry

Fentanyl is a member of the phenylpiperdine class of synthetic opioids. Its structure features a piperidine ring bound at its nitrogen constituent R_N to a phenyl ring through an ethyl chain. The opposite carbon of the piperidine ring is bonded to the nitrogen member of a propanamide group, a 3 carbon chain with a nitrogen constituent adjacent to a carbon bonded to a ketone oxygen. This propanamide group is also substituted with an additional phenyl ring at R_N.

Pharmacology

The recreational effects of this compound occur because opioids structurally mimic endogenous endorphins which are naturally found within the body and also work upon the μ-opioid receptor set. The way in which opioids structurally mimic these natural endorphins results in their euphoria, pain relief and anxiolytic effects. This is because endorphins are responsible for reducing pain, causing sleepiness, and feelings of pleasure. They can be released in response to pain, strenuous exercise, orgasm, or general excitement.

Fentanyl's strong potency in relation to that of morphine is largely due to its high lipophilicity (the ability of a chemical compound to dissolve in fats, oils, and lipids). Because of this, it can more easily penetrate the central nervous system in comparison to other opioids.

Subjective effects

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.

It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.

Physical effects

• Pain relief - In comparison to other opiates, fentanyl can be described as a strong analgesic, providing relief even at non-recreational doses.
• Physical euphoria - This particular substance can be considered as less intense in its physical euphoria when compared with that of morphine or diacetylmorphine (heroin). The sensation itself can be described as strong feelings of intense physical comfort, warmth and bliss which spread throughout the body.
• Itchiness - This compound presents very little itch response due to little to no amounts of histamines being released, unlike other opioids.
• Respiratory depression - In comparison to other opiates, fentanyl displays this effect at lower doses relative to euphoria then other opiates, and even at low doses results in the sensation that the breath is slowed down mildly to moderately, but does not cause noticeable impairment. At high doses and overdoses, opioid-induced respiratory depression can result in a shortness of breath, abnormal breathing patterns, semi-consciousness, or unconsciousness. Severe overdoses can result in a coma or death without immediate medical attention.
• Sedation - Fentanyl can be described as much more sedating then other opiates. Even at moderate dosages, this compound can result in overwhelming feelings of sedation and tiredness that is considerably more sedating than that of heroin and oxycodone.
• Constipation
• Cough suppression
• Decreased libido
• Difficulty urinating
• Pupil constriction
• Increased perspiration
• Low blood pressure
• Appetite suppression
• Orgasm suppression

Cognitive effects

• Cognitive euphoria - This particular substance can be considered as less intense in its cognitive euphoria when compared with that of morphine or diacetylmorphine (heroin) due to the upper limit of how much can be converted into its active form through metabolism. It is still, however, capable of extreme intensity and overwhelming bliss at heavier dosages with a low tolerance. The sensation itself can be described as powerful and overwhelming feeling of emotional bliss, contentment, and happiness.
• Anxiety suppression
• Compulsive redosing
• Dream potentiation

Experience reports

There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:

• Erowid Experience Vaults: Fentanyl

Toxicity and harm potential

Fentanyl by New Hampshire state police forensic lab - This image serves as a portrayal of lethal doses for heroin and fentanyl.

Non-medical use of fentanyl by individuals without opiate tolerance can be very dangerous and has resulted in numerous deaths. It is potentially fatal at heavy dosages and even those with opiate tolerances are at high risk for overdoses. Once the fentanyl is in the user's system, it is extremely difficult to stop its course because of the nature of absorption. Because of the extremely high strength of pure fentanyl powder, it is very difficult to dilute appropriately, and often the resulting mixture may be far too strong and, therefore, very dangerous. It is also [[Toxicity::potentially lethal when mixed with depressants like alcohol or benzodiazepines]].

Like most opioids, unadulterated fentanyl at appropriate dosages does not cause many long-term complications other than dependence and constipation. Outside of the extremely powerful addiction and physical dependence, the harmful or toxic aspects of opioid usage are exclusively associated with not taking the necessary precautions in regards to its administration, overdosing and using impure products.

It is important to consider that particular care must be taken with fentanyl due to its extreme potency and ability to be absorbed through the skin. This means that simply unintentionally spilling a very small amount of fentanyl on one's skin could result in a fatal overdose.

Heavy dosages of fentanyl can result in respiratory depression, leading onto fatal or dangerous levels of anoxia (oxygen deprivation). This occurs because the breathing reflex is suppressed by agonism of µ-opioid receptors proportional to the dosage consumed.

Fentanyl can also cause nausea and vomiting; a significant number of deaths attributed to opioid overdose are caused by aspiration of vomit by an unconscious victim. This is when an unconscious or semi-conscious user who is lying on their back vomits into their mouth and unknowingly suffocates. It can be prevented by ensuring that one is lying on their side with their head tilted downwards so that the airways cannot be blocked in the event of vomiting while unconscious (also known as the recovery position). In case of overdose, it is advised to administer a dose of naloxone intravenously or intramuscularly to reverse the effects of opioid agonism.

It is strongly recommended that one use harm reduction practices when using this drug.

Tolerance and addiction potential

As with other opioids, the chronic use of fentanyl can be considered extremely addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal symptoms may occur if a person suddenly stops their usage.

Tolerance to many of the effects of fentanyl develops with prolonged and repeated use. The rate at which this occurs develops at different rates for different effects, with tolerance to the constipation-inducing effects developing particularly slowly for instance. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). Fentanyl presents cross-tolerance with [[Cross-tolerance::all other opioids]], meaning that after the consumption of fentanyl all opioids will have a reduced effect.

The risk of fatal opioid overdoses rise sharply after a period of cessation and relapse, largely because of reduced tolerance. To account for this lack of tolerance, it is safer to only dose a fraction of one's usual dosage if relapsing. It has also been found that the environment one is in can play a role in opioid tolerance. In one scientific study, rats with the same history of heroin administration were significantly more likely to die after receiving their dose in an environment not associated with the drug in contrast to a familiar environment.

Dangerous interactions

Although many drugs are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses of each but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.

• Depressants (1,4-Butanediol, 2m2b, alcohol, barbiturates, benzodiazepines, GHB/GBL, methaqualone) - This combination can result in dangerous or even fatal levels of respiratory depression. These substances potentiate the muscle relaxation, sedation and amnesia caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
• Dissociatives - This combination can result in an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
• Stimulants - It is dangerous to combine fentanyl, a depressant, with stimulants due to the risk of excessive intoxication. Stimulants decrease the sedative effect of fentanyl, which is the main factor most people consider when determining their level of intoxication. Once the stimulant wears off, the effects of fentanyl will be significantly increased, leading to intensified disinhibition as well as other effects. If combined, one should strictly limit themselves to taking a certain amount of fentanyl.

Legal issues

This legality section is a stub. As such, it may contain incomplete or wrong information. You can help by expanding it.

History

Fentanyl was first synthesized by Paul Janssen in 1960 following the medical inception of pethidine several years earlier. Janssen developed fentanyl by assaying analogues of the structurally related drug pethidine for opioid activity. The widespread use of fentanyl triggered the production of fentanyl citrate which entered the clinical practice as a general anaesthetic under the trade name Sublimaze in the 1960s. Following this, many other fentanyl analogues were developed and introduced into medical practice, including sufentanil, alfentanil, remifentanil, and carfentanil.

In the mid-1990s, fentanyl was first introduced for widespread palliative use with the clinical introduction of the Duragesic patch. It was followed in the next decade by the introduction of the first quick-acting prescription formulations of fentanyl for personal use, the Actiq lollipop and Fentora buccal through the delivery method of estradiol Mylan transdermal patches. As of 2012, fentanyl was the most widely used synthetic opioid in clinical practice with several new delivery methods now available, including a sublingual spray for cancer patients. In 2013, 1700 kilograms were used globally.

See also

• Responsible use
• Opioid
• Heroin
• Morphine
• Acetylfentanyl

External links

• Fentanyl (Wikipedia)
• Fentanyl (Erowid)
• Fentanyl (Tripsit)
• Fentanyl (The Drug Classroom)