As pharmaceutical companies are approaching the final stages of development for a new type of painkiller said to be 10 times stronger than Vicodin, addiction experts worry a new wave of abuse may soon follow.
Four companies have begun patient testing on the pills which contain a pure version of the highly addictive painkiller hydrocodone, and one of them - Zogenix of San Diego - plans to apply early next year to begin marketing its product, Zohydro.
If approved, it would mark the first time patients could legally buy pure hydrocodone. Existing products combine the drug with nonaddictive painkillers such as acetaminophen.
Hydrocodone belongs to family of drugs known as opiates or opioids because they are chemically similar to opium. They include morphine, heroin, oxycodone, codeine, and methadone.
Critics are especially worried about Zohydro, a timed-release drug meant for managing moderate to severe pain, because abusers could crush it for an intense, immediate high.
"I have a big concern that this could be the next OxyContin," said April Rovero, president of the National Coalition Against Prescription Drug Abuse. "We just don't need this on the market."
OxyContin, introduced in 1995 by Purdue Pharma of Stamford, Conn., was designed to manage pain with a formula that dribbled one dose of oxycodone over many hours. Abusers quickly discovered they could defeat the timed-release feature by crushing the pills. Purdue Pharma changed the formula to make the pill more tamper-resistant, but addicts have moved onto generic oxycodone and other drugs that are not time-released.
Oxycodone is now the most-abused medicine in the U.S., with hydrocodone second, according to the Drug Enforcement Administration.
The latest drug studies come as more pharmaceutical companies are getting into the $10 billion-a-year legal market for powerful yet highly addictive opioid narcotics.
"It's like the wild west," said Peter Jackson, co-founder of Advocates for the Reform of Prescription Opioids. "The whole supply-side system is set up to perpetuate this massive unloading of opioid narcotics on the American public."
Pharmaceutical companies say the new drugs give doctors another tool to help patients in legitimate pain.
"Sometimes you circulate a patient between various opioids, and some may have a better effect than others," said Karsten Lindhardt, chief executive of Denmark-based Egalet, which is testing its own pure hydrocodone product.
Pure hydrocodone pills would avoid liver problems linked to high doses of acetaminophen, an ingredient in products like Vicodin, according to the drug companies. They also say patients will be more closely supervised because they will have to return to their doctors each time they need more pills. Prescriptions for the weaker, hydrocodone-acetaminophen products can be refilled up to five times.
Zogenix has completed three rounds of patient testing, and last week it announced it had held a final meeting with FDA officials to talk about its upcoming drug application. It plans to file the application in early 2012 and have Zohydro on the market by early 2013.
Purdue Pharma and Cephalon, a Frazer, Pa.-based unit of Israel-based Teva Pharmaceuticals, are conducting late-stage trials of their own hydrocodone drugs, according to documents filed with federal regulators. In May, Purdue Pharma received a patent applying extended-release technology to hydrocodone.
Egalet has finished the most preliminary stages of safety testing and could have a product on the market as early as 2015 but wants to see how the other companies fare with the FDA before deciding whether to move forward, Lindhardt said.
Critics are troubled because a new narcotic painkiller can lead to more murders, pharmacy robberies, and millions of dollars lost by hospitals to treat overdose victims. Thousands of legitimate pain patients are becoming addicted to powerful prescription painkillers, they say, in addition to the thousands more who abuse them illegally.
The CDC said last month that prescription painkillers caused 15,000 U.S. deaths in 2008, more than triple the 4,000 deaths in 1999.
Emergency room visits related to hydrocodone abuse have shot from 19,221 in 2000 to 86,258 in 2009, according to the DEA. In Florida alone, hydrocodone caused 910 deaths and contributed to 1,803 others between 2003 and 2007.
Opiates block pain but also unleash intense feelings of well-being and can create physical dependence. Withdrawal symptoms can be intense, causing cramps, diarrhea, muddled thinking, nausea and vomiting. After a while, opiates stop working, forcing users to take stronger doses.
"You've got a person on your product for life, and a doctor's got a patient who's never going to miss an appointment, because if they did and they didn't get their prescription, they would feel very sick," said Andrew Kolodny, president of Physicians for Responsible Opioid Prescribing. "It's a terrific business model, and that's what these companies want to get in on."
The U.S. consumes 99 percent of the world's hydrocodone and 83 percent of its oxycodone, according to a 2008 study by the International Narcotics Control Board.