Fentanyl: Uses, Side Effects, Medicolegal Importance & PM 09Appearances

Fentanyl: Uses, Side Effects, Medicolegal Importance & PM 09Appearances

Fentanyl is a potent synthetic opioid similar to morphine and it produces analgesia to a greater extent i.e. 50-100 times more than morphine. A dose of only 100 micrograms can produce equivalent analgesia to approximately 10 milligrams of morphine.

It is a phenylpiperidine derivative which is structurally similar to pethidine and has become a common drug of abuse and an adulterant in illicit drugs because of its high potency.

Fentanyl is popular among the people with the street names such as ‘apace’, ‘china girl’, ‘china white’, ‘china town’, ‘dance fever’, etc.

Fentanyl is available in a water soluble, white crystalline powder that requires no preservative. The molecular formula for fentanyl is C₂₂H₂₈N₂O and molecular mass is 336.471g/mol.

N-(1-(2-phenethyl)-4-piperidinyl-N-phenyl propanamide

Derivatives of fentanyl include Alfentanil, Sufentanil, Remifentanil, and Carfentanil.

Uses of Fentanyl

Fentanyl is administered intravenously (IV), intramuscularly(IM), transdermally as skin patches, intranasally in the form of a volatile nasal spray and intrathecally. Fentanyl IV or IM injections are indicated for short term analgesia during induction, maintenance and recovery from general or regional anesthesia.

The injections are also used with a neuroleptic for premedication, induction and as an adjunct to maintenance of anesthesia. They are also used with oxygen for anaesthesia in high risk patients.

Fentanyl sublingual tablets, transmucosal lozenges, buccal tablets, sublingual sprays, transdermal systems and nasal sprays are indicated for the management of breakthrough pain in opioid tolerant cancer patients who require around the clock pain management.

Effects of Using Fentanyl

Fentanyl is a mu(𝜇) selective opioid agonist. However, it has the capability to activate other opioid system receptors such as delta(𝛿) and potentially kappa(𝜅) receptors. This activation produces analgesia, a significant feature of fentanyl.

Dopamine level is increased in the reward area of the brain, which elicit the stereotypically associated with the addiction to the drug.

Since fentanyl is more potent than morphine and heroin, therefore it is produces more adverse effects which are:

  • Analgesia
  • Euphoria
  • Confusion
  • Marked respiratory depression
  • Vagal inhibition which decreases heart rate
  • Drowsiness
  • Nausea
  • Visual disturbances 
  • Dyskinesia
  • Muscle rigidity
  • Constipation
  • Irregular menstruation
  • Decreased sexual desire
  • Seizures
  • Hives
  • Itching and rashes
  • Addiction
  • Loss of consciousness
  • Hypotension
  • Coma and in severe conditions death is also caused

Fentanyl along with other drugs(heroin, cocaine, alcohol, etc.) leads to synergism and causes undesirable conditions that complicate the patient’s prognosis.

Naloxone acts as a treatment drug to counteract respiratory depression and mental clouding.

Medicolegal Importance

  • Fentanyl is deliberately mixed with heroin to increase its potency and sold in the market as pure fentanyl disguising the users, which causes overdose deaths.
  • Fentanyl is manufactured clandestinely in countries like Mexico.
  • Homicide and suicide using fentanyl is not common. Since it is used medically, accidental deaths due to overdose may happen.

Postmortem Appearances

Post mortem appearances of fentanyl poisoning are similar to those of the heroin which includes the following:

  • Body emits smell of opium
  • Injection marks may be seen on the forearm, back of hands, etc.
  • Froth at the nostrils
  • Constricted/dilated pupil
  • All organs are congested, trachea contains frothy secretions 
  • Bradycardia 
  • Lungs present with gross oedema and froth coming out from the mouth and nostrils
  • Smell of opium is perceived which disappears with onset of putrefaction

Fentanyl shows postmortem redistribution (process of diffusion of drug from the tissues to blood along a concentration gradient between death and the time of specimen collection at the autopsy).

Researchers have shown that the liver fentanyl concentrations are more optimal than the blood fentanyl concentration for the determination of fentanyl concentration in the body in poisoning cases.


Fentanyl is a synthetic opioid drug and have high medical application but also one of the dangerous drugs with high potency. Therefore, it is very important to use it cautiously in the hospitals. Also regulatory bodies should ensure its limited production and supply. Strict laws should be amended to prevent the illicit supply of fentanyl.

It is also the responsibility of the general public to be aware about the drug addiction from such drugs and use them only on prescriptions by doctors.

Leave a Reply

Your email address will not be published. Required fields are marked *