Vol 14 Edition 2

Fentanyl and carfentanyl: what do I need to know?

Its street name is “China White”. Fentanyl, and its analogues (compounds that resemble fentanyl in structure) are rising, relative newcomers to the opioid market.  They carry a lethal potency and are dramatically more powerful than heroin.

In the US a large percentage of overdose deaths result from heroin that has been “laced” with fentanyl analogues, or from counterfeit pharmaceutical pills containing the drug. The autopsy of musician Prince ruled that he died of an overdose resulting from counterfeit hydrocodone pills that actually contained fentanyl.

Outreach Coordinator at WASUA (The Western Australian Substance Users Association) Paul Dessauer, explains, “Fentanyl is a powerful synthetic opioid with a rapid onset and short duration of action, used widely in medicine for pain relief and as a general anaesthetic.

“When used via parenteral routes – as in subcutaneous, intramuscular or intravenous – it is 100 times more potent than morphine. This means 1 milligram of fentanyl administered by injection has roughly the same effect as 100 milligrams of injected morphine. By way of comparison, an intravenous dose of pure heroin – diacetylmorphine – is ‘only’ three times as potent as the same weight of IV morphine.”

Paul says that fentanyl and its analogues can be injected, ingested, inhaled, taken across mucous membranes, and via transdermal (through the skin) routes. Fentanyl analogues might be purchased via dark-web vendors or research chemical suppliers, or may be ‘cut’ into illicit heroin. Alternatively, turning up on the black market could be the pharmaceutical products that the drugs were created for; prescription-only medicines containing fentanyl or its analogues, including trans-dermal patches, lollypops and nasal sprays, and ampoules for injecting use.

Alarmingly, Australian Customs recently intercepted a shipment of carfentanyl.

Carfentanyl (or carfentanil) is the strongest available analogue of fentanyl, roughly 10,000 times more potent than morphine. If you need to anaesthetise an elephant or a whale, this is the drug for you. If somebody is looking to self-inject, not so much.

Fatal doses compared: heroin, fentanyl and carfentanil
Image: Bruce Taylor, New Hampshire State Police Forensic Lab

Paul says that because of Australia’s geographic proximity to the primary source of high-quality salt heroin in Myanmar, and our geographic isolation from traditional North American and Latin American sources of black-market fentanyl, we’ve been largely protected until now. But Paul believes that could be changing.

He says the attraction to major traffickers is obvious. “Carfentanyl can be sourced more cheaply (per equivalent dose) than heroin; it is roughly one-thirty-three thousandth (1/3300th) the bulk of a dose-equivalent weight of heroin; and sniffer dogs and Ion-tracking equipment will not detect it,” he says.

“Once imported it could be bulked out with poorer quality heroin, or even an inert powder, to turn an insignificant pinch of dust into thousands of street-deals. To major traffickers, the risk of interdiction or arrest are significantly lower and the potential profit margins are much higher.”

The major danger to users is that such tiny amounts of carfentanyl can kill. Paul says that while the drug has never been tested on humans, it is believed a lethal dose might only be 20mcg = 0.02mg (milligrams). For comparison, the lethal human dose of pharmaceutical-grade fentanyl is 2mg, and a lethal dose of morphine is usually calculated as 200mg, (although doses as low as 60mg have killed opioid naive people).

To put it more starkly, if you want to picture what 20 mcg of carfentanyl looks like, consider a single small grain of salt. Crush that into powder or mix it into water, then add to other drugs, and users could have no idea what they’re about to absorb.

The only way to accurately measure fentanyl, carfentanyl or the other analogues is with highly precise scales costing upwards of $10,000.

“The traditional advice we offer when someone is unsure of how strong a deal of heroin might be is to test a small sample first,” Paul says.

“You know, ‘two holes in the arm are better than one hole in the ground’. However, when a fentanyl analogue is mixed into heroin, only a speck or two of difference could mean that one half of the packet is tens or even hundreds of times stronger than the other.

“The best advice for individual users is to avoid using alone, and to stagger their use – that is, take it in turns and wait long enough to ensure the first person is okay before injecting their own dose – or to use in a medically-supervised setting if one is available.”

Minimising risk to first-aiders:

In response to a suspected exposure to potent synthetic opioids:

  • Call 000 immediately and administer first-aid as per an opioid overdose.
  • Avoid handling any drug material or paraphernalia at the scene.
  • Wear nitrile or latex gloves and use a face shield if available. As a last resort a simple face shield can be improvised from a piece of plastic bag with a hole in the centre.
  • Ongoing ventilation and multiple doses of naloxone may be required.
  • If inhalation exposure is suspected, ensure the victim has fresh air.
  • If ingestion is suspected and the victim is conscious they should be encouraged to flush their mouth, eyes and nose with fresh running water.
  • If contact exposure is suspected and the person is conscious, flush the area under running water. However this will probably only help within a very short time of the contact.

– Nick Place

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