Fentanyl

Fentanyl is often mixed with other substances and consumed without the user’s awareness. People who use substances that have been mixed with fentanyl are likely to experience serious and/or life-threatening adverse effects because fentanyl is a powerful opioid causing intense effects in small doses (Kuczyńska et al., 2018)

Fentanyl causes the user to experience a range of psychological and physiological effects generally causing the user to experience relaxation and euphoria (CAMH, 2021). Physiologically, fentanyl causes the user to sweat and slows their breathing (CAMH, 2021). These effects may vary depending on how much is used, frequency of use, and the route of administration. Other effects may include:

• Suppression of appetite.
• Difficulty concentrating

In small doses of as little as 2mg, fentanyl can cause serious and life-threatening adverse effects (Kuczyńska et al., 2018). These effects can occur very suddenly and can include:

• Shortness of breath or sudden respiratory difficulties.
• Blurry vision.
• Nausea and/ or vomiting.
• Anxiety, agitations/aggression.
• Paranoia and hallucinations.
• Numbness, tingling, or pins and needles in the back of the head and neck.
• Convulsions.
• Unconsciousness.
• Coma.
• Death.

The onset effects are rapid and generally last for 1-2 hours (Kuczyńska et al., 2018). Since many users are unaware that they have consumed fentanyl, they may mistake the effects of fentanyl with the substance they intended to use.

When fentanyl is knowingly being used for recreational purposes, it is most commonly sold as a powder, liquid, or tablet form (Kuczyńska et al., 2018). Fentanyl can be dissolved and injected intravenously or intramuscularly, smoked, ingested, or sprayed/snorted into the nose (Kuczyńska et al., 2018). Injecting fentanyl intravenously poses the greatest risk of life-threatening adverse effects as the onset of effects are rapid and intense (Abdulrahim & Bowden-Jones, 2018).

Prescribed Substances

Fentanyl may produce serious and life-threatening adverse effects when used with certain HIV medications, antidepressants, antifungals and antibiotics.

HIV Medications

• Ritonavir and Cobicistat are used to boost the availability of other substances (primarily other HIV medications) in the body by decreasing the breakdown speed of these substances (Nuh, 2020).
• Ritonavir and Cobicistat interact with fentanyl by increasing the availability of fentanyl in the body, leading to adverse effects (Abdulrahim & Bowden-Jones, 2018).
• Fentanyl interacts with other HIV medications including indinavir and saquinavir leading to serious and life-threatening adverse effects (Abdulrahim & Bowden-Jones, 2018)

Antidepressants

• Fentanyl may interact with Monoamine Oxidase Inhibitors (MAOIs), Selective Serotonin Reuptake Inhibitors (SSRIs), and Selective Norepinephrine Reuptake Inhibitors (SNRIs) contributing to Serotonin Syndrome/Toxicity (Abdulrahim & Bowden-Jones, 2018).
• Serotonin Agonist and Reuptake Inhibitors (SARIs) may also interact with fentanyl, leading to adverse effects (Abdulrahim & Bowden-Jones, 2018).

Antifungal and/or Antibiotics

• Fluconazole, itraconazole, and ketoconazole are antifungal medications that interact with fentanyl by increasing the availability of fentanyl in the body, leading to adverse effects (Abdulrahim & Bowden-Jones, 2018).
• Clarithromycin and erythromycin are antibiotics that interact with fentanyl by increasing the availability of fentanyl in the body, leading to adverse effects (Abdulrahim & Bowden-Jones, 2018).

Recreational Substances

When fentanyl is used with other recreational substances, this is known as polysubstance use and can lead to serious or life-threatening adverse effects.

Alcohol

• Fentanyl interacts with alcohol to exacerbate CNS depression, increasing risk of serious and/or life-threatening adverse effects (Abdulrahim & Bowden-Jones, 2018)

MDMA

• MDMA interacts with fentanyl by increasing availability of fentanyl in the body, leading to serious and/or life-threatening adverse effects (Abdulrahim & Bowden-Jones, 2018).

Benzodiazepines

• Fentanyl interacts with benzodiazepines to exacerbate CNS depression, increasing risk of serious and/or life-threatening adverse effects (Abdulrahim & Bowden-Jones, 2018).

Recently, Canada passed the “Good Samaritan Drug Overdose Act.” This means that if police attend a 911 call for an overdose and there are drugs present, anyone in attendance is protected against simple drug possession charges, even if they’re on probation or parole. See this helpful info by the Canadian HIV/AIDS Legal Network. You can download a PDF of it [here].