The withdrawal of a popular painkiller from the market in the United Kingdom has led to a dramatic decrease in the number of suicides and accidental overdoses in that country, according to a study conducted by researchers from Oxford University’s Centre for Suicide Research and published in the British Medical Journal.

The drug in question is a combination of the narcotic painkiller dextropropoxyphene (in the opioid family) with the over-the-counter painkiller acetaminophen, also known as paracetamol or Tylenol. In the United Kingdom, the drug was marketed as co-proxamol, but it is also known as Darvon with APAP, Capadex, Di-Antalvic, Di-Gesic and Lentogesic.

In 2005, the British Medicines and Healthcare Products Regulatory Agency (MHRA) decided to remove co-proxamol from the market after statistics emerged suggesting that the drug was particularly dangerous, causing between 300 and 400 self-poisoning deaths every year. Approximately 80 percent of these deaths were intentional suicides.

The agency instructed doctors to phase out use of the drug by 2007, and over that period prescriptions of co-proxamol fell 59 percent and deaths from the drug fell 62 percent. This translated into 295 fewer suicides and 54 fewer accidental overdoses from the drug. Significantly, there was no concurrent increase in suicides or accidental overdoses from other painkillers, even though use of those drugs increased correspondingly.

“This marked reduction in suicides and accidental poisonings involving co-proxamol during this period, with no evidence of an increase in deaths involving other analgesics, suggests the initiative has been effective,” lead researcher Keith Hawton said.

“Co-proxamol is extremely dangerous in overdose — only a small overdose can be fatal, and death can occur very rapidly — before medical attention can be sought,” an MHRA spokesperson said. “[In addition,] there is no robust evidence that co-proxamol offers any advantage over paracetamol or ibuprofen at normal doses.”

The FDA is currently considering whether to withdraw the drug from the U.S. market.

Sources for this story include: news.bbc.co.uk.