The death of Hollywood actor Hayden Panettiere of ‘Heroes’ and ‘Nashville’ fame has once again drawn attention to the dangers of fentanyl, a synthetic opioid so potent that even an amount too small to see can carry a serious overdose risk.Panettiere, 36, was found unresponsive at a residence in Greenville, South Carolina. The Greenville County Coroner’s Office has now ruled her death accidental and said it was caused by the toxic effects of fentanyl, along with 4-ANPP, alprazolam, methocarbamol and quetiapine. The autopsy found no trauma that contributed to her death.Fentanyl is a potent, fast-acting synthetic opioid, meaning it can be chemically manufactured in a laboratory. To compare, opioids such as morphine and codeine are derived from the opium poppy plants. These are a class of medication usually used for the management of severe pain in cancer patients or those who have undergone various surgeries. These drugs can be extremely addictive.What makes fentanyl a bigger problem is the fact that it can be 30 to 100 times more potent than heroin or morphine and is fast acting, leading to a rapid and high number of overdose deaths.Illegally manufactured fentanyl can be sold as a powder or pressed into counterfeit pills made to look like other prescription medicines. A person taking an illicit or counterfeit product may not know that it contains fentanyl. That unpredictability is one reason fentanyl has become such a major contributor to fatal overdoses.Why is fentanyl so dangerous?Like other opioids, fentanyl acts on opioid receptors in the brain and nervous system. These receptors influence pain, breathing and other body functions.In an overdose, the drug can suppress the brain’s drive to breathe. Breathing may become extremely slow or stop altogether, depriving the brain and other organs of oxygen. Without rapid treatment, this can lead to brain injury and death.Story continues below this adIts high potency means that the margin between an amount that produces an opioid effect and an amount that causes dangerous respiratory depression can be much narrower than with less potent opioids. However, there is no single amount that can be described as a universally fatal dose. The effect depends on factors including opioid tolerance, individual health, the way the drug is taken and whether it is combined with other substances.Why can mixing drugs increase the risk?Panettiere’s toxicology report listed fentanyl alongside several other substances, including alprazolam, a benzodiazepine, and methocarbamol, a muscle relaxant. Combining opioids with other drugs that cause sedation can increase the risk of dangerous respiratory depression.What does a fentanyl overdose look like?An opioid overdose can cause:Very slow, shallow or stopped breathingExtreme sleepiness or inability to wake upPinpoint pupilsA limp bodyChoking, gurgling or unusual breathing soundsPale, blue or cold skinIf someone is unusually difficult to wake and opioid overdose is possible, it should be treated as a medical emergency.Story continues below this adCan naloxone reverse a fentanyl overdose?Naloxone, also known by the brand name Narcan, can rapidly reverse an opioid overdose by blocking the effects of opioids such as fentanyl. It can restore normal breathing within minutes when an overdose has slowed or stopped breathing, although more than one dose may be needed with potent opioids such as fentanyl. Emergency medical help should still be called, even if the person responds to naloxone. The key is speed: naloxone does not replace emergency medical care, and its effects can wear off while the opioid remains in the body.What is the health impact of fentanyl addiction?An estimated 74,702 people died of fentanyl overdose in the United States in 2023, according to the country’s Centres for Disease Control and Prevention (CDC). This, however, was a decline over the previous year’s 76,226 deaths. The CDC said that it was the first time there was a decline in overdose deaths since 2018. Nevertheless, fentanyl-related overdoses resulted in more than 69% of the total overdose deaths in the US.What of fentanyl use in India?In India, heroin and its derivatives like smack continue to be the most common opioids leading to addiction. An estimated 63 lakh people are addicted to heroin as compared to 25 lakh to pharmaceutical opioids, according to a2019 survey called Magnitude of Substance Use in India by the AIIMS National Drug Dependence and Treatment Centre.