Fentanyl is starting to hit the headlines in the UK. The drug is not so well-known this side of the Atlantic but, if experiences in America are anything to go by, that will change. Sadly, fentanyl is a problem that is unlikely to be going away.

Fentanyl is a powerful pain-relieving drug, 50 times more potent than morphine, and was originally synthesised by Belgian chemist Paul Jannsen. The drug has medical applications, for example, in anaesthesia and relieving pain from major surgery or cancer.

The drug interacts with the same opioid receptors as morphine and heroin and is therefore called an opioid, even though it is chemically unrelated to opiates (drugs derived from opium poppies). Opioid receptors are part of the body’s reward pathway. Chemicals are released in our body to make us feel good as a reward for activities that help us survive and procreate, such as eating, drinking and sex. Increasing the presence of feelgood chemicals in our body is why opiates and opioids can be so powerfully addictive.

The body responds to repeated doses of opioids by desensitising the receptors. It means more opioid drugs have to be taken to achieve the same level of pain relief, when taken for medical reasons, or to reach the same high if taken recreationally. This is the development of tolerance. Those who have been taking opioids for a a longer period can cope with quantities that would kill new users or those who have lost their tolerance through a break in taking the drug.

For regular users, reducing the dose or stopping it means the body suddenly has receptors that need huge stimulation to relieve pain but no drug to stimulate them. Withdrawal from opioids can be agony. Every bone in the body hurts, you experience severe cold and goose bumps – hence the phrase “cold turkey”. With fentanyl the high is greater and so is the withdrawal. The desire to take more of the drug can be overwhelming.

Since the 1960s the fentanyl backbone has been modified and tinkered with to produce a huge number of variants that will differ in their interactions in the body. Some variants are more powerful sedatives than others and they differ in how long before they take effect. Carfentanil, for example, is thousands of times more powerful than morphine and is used to tranquilise elephants. It is so powerful that those who work with elephants, park rangers etc., are required to have two people present if they are planning to use carfentanil darts. One person is there to fire the dart, and the other, sitting next to them with the antidote ready, in case of an accidental scratch. Incredibly there have been cases of human consumption of carfentanil, spiked in heroin or cocaine.

Because fentanyl interacts with the same receptors as morphine, the same antidote can be used. Naloxone, also marketed as Narcan, binds to opioid receptors but doesn’t stimulate them, it simply blocks the site where the opioid would bind and reverses all the opioid’s effects. However, fentanyl binds much more strongly to these receptors meaning a much larger dose of the antidote is needed. Emergency staff in the US have been known to administer a dozen or more doses of naloxone in cases of fentanyl overdose with no appreciable effect.

The intense and rapid high produced by fentanyl has made it attractive drug for recreational use. Cutting fentanyl with drugs like heroin and cocaine dramatically intensifies the potency and makes it far more addictive, benefiting drug dealers with very dependent consumers. It also dramatically increases in chances of dying. Just two milligrams of fentanyl can be fatal for an adult. Fentanyl has become a large part of America’s opioid crisis.

Fentanyl kills for the same reasons that opiates kill – they slow respiration until it stops. Death is by suffocation. Drugs administered by prescription or in hospital environments are quality controlled and used where the effects can be monitored and action taken if something goes wrong. By definition there is no such control in the illegal drugs trade. What is sold on the street could be anything from a little heroin, diluted with something fairly innocuous, to pure fentanyl.

It was recently reported that fentanyl has claimed the lives of at least 60 people in the UK over the last eight months. Sixty is a large number but it pales in comparison to the number of lives claimed by the drug in the US.

The process of making drugs is often frighteningly easy. For example, converting morphine to its far more addictive form heroin is an easy process that can be carried out with minimal knowledge and equipment. It is an attractive prospect for those wanting to make a quick profit. The biggest problem would be obtaining the raw materials, which in the case of morphine/heroin isn’t particularly difficult if you know where to look.

Fentanyl offers much greater profits per kilo than heroin but also presents greater problems. The chemistry needed to make fentanyl and its related compounds is not that difficult, at least on paper. Obtaining the raw materials is not the hardest part. The real problems occur in the practicalities of the chemical process needed to manufacture the drugs. These compounds are so potent that accidentally inhaling tiny quantities of fentanyl powder, or getting small amounts in a cut on the skin, could prove fatal. But, because it requires relatively specialised knowledge, the number of people producing fentanyl drugs illegally is quite small. However, because what they produce is so potent, a little bit goes a long way, and there is the potential to affect huge numbers of drug users.

On the positive side, if law enforcement can shut down just a few fentanyl factories it can dramatically reduce the number drug-related deaths. But even shutting down these factories is not straightforward. Drug raids have to be carefully planned. Going in all guns blazing can result in fentanyl powder being blown up into the air and officers needing emergency medical treatment. A police officer in the US was hospitalised simply because of brushing fentanyl powder off his uniform after an arrest.

There is no obvious quick fix to this growing problem. Reducing the number of opioid prescriptions may help lower the number of people who become addicted. Knowledge of the appalling effects of fentanyl may at least raise awareness but the chances of it deterring people from taking the drug seems a vain hope. One way of maybe reducing the number of deaths is making the opioid-blocker naloxone more widely available, but this is far from being a solution to the problem. Other ideas put forward have included making safer supplies of drugs available to users, at least temporarily. Leaving things as they are is not an option unless you want to see thousands more die. I sincerely hope I am wrong, but the future looks bleak.

• This article was amended on 29 May 2019 because an earlier version implied that fentanyl can be absorbed through the skin, when it said that touching equipment contaminated with the drug can prove fatal. That is actually very difficult, but it can be absorbed through mucous membranes and the article has been edited to reflect this.