Darvon and Darvocet, both built on the painkiller propoxyphene, were once among the most prescribed drugs in the US.1Saiontz & Kirk. Why Was the Darvon Medication Removed From the Market? In 2010 the FDA asked for them to be withdrawn because the drug could disrupt the heart’s rhythm, a risk judged greater than its benefit.2PubMed Central. QTc interval prolongation by d-propoxyphene: what about other analgesics? As pain relief, it did no better than safer drugs already on pharmacy shelves.3Public Citizen. Public Citizen Petitions FDA to Ban Darvon Products
How Propoxyphene Harmed the Heart
The liver turns propoxyphene into norpropoxyphene, a substance with no pain-relieving effect that is toxic to the heart.4PubMed. Propoxyphene (dextropropoxyphene): a critical review of a weak opioid analgesic that should remain in antiquity In people who died after taking propoxyphene, blood levels of norpropoxyphene were usually higher than those of the drug itself.5PubMed. Propoxyphene and norpropoxyphene tissue concentrations in fatalities associated with propoxyphene hydrochloride and propoxyphene napsylate It builds up in heart tissue.6PubMed. Norpropoxyphene-induced cardiotoxicity is associated with changes in ion-selectivity and gating of HERG currents It also crosses into the brain less easily than propoxyphene does.7PubMed. Propoxyphene and norpropoxyphene tissue concentrations in fatalities associated with propoxyphene hydrochloride and propoxyphene napsylate So the breathing trouble and drowsiness of a typical opioid overdose were only part of the risk.
The two substances also leave the body at different speeds. Propoxyphene clears faster than its breakdown product, so they don’t rise and fall together. A person could feel the pain relief fade while the heart-toxic substance was still present.
Propoxyphene blocks sodium channels, the tiny gates that carry each heartbeat’s electrical signal through heart muscle.8PubMed Central. Marked QRS complex abnormalities and sodium channel blockade by propoxyphene reversed with lidocaine With the gates partly blocked, the signal slows and can lose coordination, so the heart pumps less effectively. On a heart tracing (ECG), the signal for each beat could spread abnormally slowly, a dangerous sign doctors watch for in overdoses.9PubMed Central. Marked QRS complex abnormalities and sodium channel blockade by propoxyphene reversed with lidocaine A person in this state might feel dizzy, faint, or have a pounding or irregular heartbeat, though some had no warning before collapsing.
The drug also lengthens the QT interval, the time the heart needs to electrically reset between beats, which can show on an ECG report.10PubMed Central. QTc interval prolongation by d-propoxyphene: what about other analgesics? After each beat the heart muscle has to recharge before the next one. If the recharge runs long, an early extra signal can land at a vulnerable moment and set off an erratic, potentially deadly rhythm.
Naloxone (Narcan), the standard opioid overdose reversal drug, does not reverse the heart damage from the breakdown product.11PubMed. Norpropoxyphene-induced cardiotoxicity is associated with changes in ion-selectivity and gating of HERG currents Naloxone can restore breathing within minutes. With propoxyphene, a person could wake up and start breathing yet still have a failing heart rhythm.
The most severe heart effects were seen in overdoses, including accidental ones from taking extra for pain. Because the breakdown product lingers, repeated doses can let it build up over days.
Weak Pain Relief That Didn’t Justify the Risk
Propoxyphene grips the body’s opioid receptors about a hundred times less tightly than morphine.12Wikipedia. Dextropropoxyphene That makes it a weak opioid, but “weak” describes how tightly the drug binds, not how dangerous it is. Some people took extra doses because the relief felt modest.
It was no more effective than safer alternatives, and it could cause physical addiction.13Public Citizen. Public Citizen Petitions FDA to Ban Darvon Products Beyond heart effects, it was linked to seizures.14PubMed. Propoxyphene (dextropropoxyphene): a critical review of a weak opioid analgesic that should remain in antiquity Seizures were a separate harm from the rhythm problems, and they could occur in people who had not taken a huge amount. Physical dependence means the body adapts, so stopping suddenly after regular use could bring withdrawal symptoms.
A drug that relieves pain no better than safer options has nothing to balance a heart danger. Darvocet’s acetaminophen was the same ingredient found in Tylenol, so people could get similar relief without the propoxyphene.
Many people still took it. Doctors often saw it as milder and safer than stronger opioids, and familiar brand names made it a routine prescription for dental and injury pain.
Why Older Adults Faced the Highest Risk
For decades, propoxyphene was on the Beers list of drugs older adults should avoid.15PubMed Central. Protecting patients from adverse drug events: propoxyphene, PIMs, and drugs to avoid in older adults The Beers list is a widely used catalog of medicines that carry extra risk for people over 65. Propoxyphene earned its place because it carried risks of confusion, dependence, and poor pain relief compared with other drugs.16PubMed Central. Protecting patients from adverse drug events: propoxyphene, PIMs, and drugs to avoid in older adults
Age made the buildup worse. The kidneys filter many drugs and their breakdown products out of the blood, and that filtering generally slows with age. Kidneys that clear waste more slowly let norpropoxyphene build up.17PubMed Central. Protecting patients from adverse drug events: propoxyphene, PIMs, and drugs to avoid in older adults The same pill on the same schedule can leave more of the breakdown product in an older person’s body, so an older adult taking an ordinary prescribed dose could still reach a harmful level over days of repeated use. Older users faced extra risk of heart problems and dangerously slowed breathing and alertness.18PubMed Central. Protecting patients from adverse drug events: propoxyphene, PIMs, and drugs to avoid in older adults
The Decades-Long Road to a Ban
In 1978 the consumer group Public Citizen asked the FDA to ban propoxyphene or heavily restrict it, and the request was turned down.19citizen.org. Excerpts from the chronology of U.S. FDA inaction on Propoxyphene (Darvon, Darvocet) Public Citizen petitioned again, citing more than 2,000 accidental deaths.20Public Citizen. Public Citizen Petitions FDA to Ban Darvon Products Prescriptions kept climbing, reaching 21.3 million in 2007 alone.21Saiontz & Kirk. Why Was the Darvon Medication Removed From the Market? About 120 million prescriptions were filled in the five years before the ban.22PBS NewsHour. Darvocet, Darvon Painkillers Pulled From Market at FDA’s Request
Deaths were hard to tie to a single cause. Many involved overdoses with other drugs or alcohol, which made it easier to argue the drug itself was not the problem. Pressure built as more evidence of heart effects accumulated and other countries acted first.
Europe moved first. The UK decided in January 2005 to withdraw co-proxamol, its propoxyphene-acetaminophen combination, finishing on 31 December 2007.23BMJ. Effect of withdrawal of co-proxamol on prescribing and deaths from drug poisoning in England and Wales: time series analysis In June 2009 the European Medicines Agency recommended withdrawing propoxyphene products across the European Union, because their risk of potentially fatal overdose outweighed their benefits.24HCPLive. Pain Medication Propoxyphene Banned25European Medicines Agency (EMA). European Medicines Agency recommends withdrawal of dextropropoxyphene-containing medicines
The US followed. An FDA advisory committee, a panel of outside experts that reviews evidence and votes on a recommendation the agency can follow or not, examined the heart rhythm data. On November 19, 2010, the FDA recommended against any further use, because the danger of a delayed heart rhythm reset was greater than the drug’s benefit.26Taylor & Francis Online / PubMed Central. Food and Drug Administration recommends against the continued use of propoxyphene27PubMed Central. QTc interval prolongation by d-propoxyphene: what about other analgesics? All forms of the drug, brand name and generic, were removed from the US market.28Taylor & Francis Online / PubMed Central. Food and Drug Administration recommends against the continued use of propoxyphene
The withdrawal was technically voluntary: the FDA asked the makers to stop selling the drug, and they agreed. For patients the effect was the same as a ban, and pharmacies stopped filling prescriptions.
If you find leftover Darvon or Darvocet at home, don’t take it, even for mild pain. Bring it to a pharmacy take-back kiosk or a drug take-back day. If neither is available, mix the pills with something unappealing such as used coffee grounds, seal them in a bag, and put them in the trash.
Did the Ban Save Lives
In Florida, deaths involving propoxyphene fell 84%, from 580 to 92, after the withdrawal.29PubMed. Fatal poisonings involving propoxyphene before and after voluntary withdrawal from the United States’ market: An analysis from the state of Florida Researchers also checked whether deaths from other opioids rose to take their place, and most switches did not cause extra harm.
Most former users moved to tramadol or hydrocodone, usually at low doses.30PubMed Central. Response to Propoxyphene Market Withdrawal: Analgesic Substitutes, Doses, and Adverse Events Serious side effects after switching were rare and no more common than in people who never took propoxyphene. Some stopped opioids entirely. About a third of former users in one large insurance group did, nearly twice the rate of people who hadn’t been taking it.31PubMed Central. Response to Propoxyphene Market Withdrawal: Analgesic Substitutes, Doses, and Adverse Events Among veterans, a quarter of long-term opioid users stopped after the withdrawal, compared with about one in seven earlier.32PubMed Central. The Influence of Propoxyphene Withdrawal on Opioid Use in Veterans For many, the drug apparently had not been doing much they needed.
Fewer people also took the risky amount of 4 grams or more of acetaminophen a day, dropping from 12% to 2%.33PubMed Central. Response to Propoxyphene Market Withdrawal: Analgesic Substitutes, Doses, and Adverse Events Darvocet contained acetaminophen, so heavy users often took a lot of it, and very high daily amounts can damage the liver.34PubMed Central. Response to Propoxyphene Market Withdrawal: Analgesic Substitutes, Doses, and Adverse Events
Can You Still Sue Over Darvon or Darvocet
In 2014 a federal appeals court sided with drug makers in the main Darvocet and Darvon lawsuit.35Lexology. Sixth Circuit delivers big win for drug manufacturers People who took generic propoxyphene could not hold the brand-name maker responsible under the laws of 22 states.36Lexology. Sixth Circuit delivers big win for drug manufacturers Courts mostly won’t blame a brand maker for a pill it didn’t make, and most Darvocet users by the end took generics, so this shut out many claims.
Claims against generic makers faced very demanding requirements just to avoid dismissal.37Southwestern Law Review. Beyond Preemption of Generic Drug Claims Federal rules require a generic label to match the brand’s, so a generic maker generally cannot change warnings on its own. Courts have often treated that as a reason it can’t be blamed for failing to warn, which leaves plaintiffs searching for a different legal theory that is hard to prove. Few new cases are likely to succeed, though facts and state law vary, and a local product-liability lawyer can say whether your state’s rules differ.
A lawyer will likely ask which product you took and who made it, often shown in old pharmacy records. They will want to know what harm occurred and when, with medical records to support it. They will also check time limits for filing, which may already have passed.