Darvon may be in jeopardy
by Mary Helen Yarborough
The narcotic pain killer Darvon may no longer be available to patients
if the Food and Drug Administration agrees with the recommendation by
two of its advisory committees to ban it.
Based on reports citing a high incidence of fatal or serious overdoses,
the FDA’s Anesthetic and Life Support Drugs Advisory and the Drug
Safety and Risk Management Advisory committees voted in a special joint
meeting on Jan. 30 to ban the drug, and products containing
propoxyphene (Darvon and Darvocet) from the U.S. market. It was
withdrawn in Great Britain in 2005.
The advisory panels agreed to gradually withdraw the drug, which has
been available since 1957, to enable the large numbers of those
prescribed to it to transition to another therapy.
Darvon is the third most widely-used narcotic pain killer behind hydrocodone and oxycodone.
Arthur Rick Smith, M.D., assistant professor of anesthesia &
perioperative medicine, and pain management expert, said that
propoxyphene has a history of controversy, including whether the
relatively mild opioid is much stronger than acetaminophen.
“Studies have shown that it may not be any stronger than Tylenol or
aspirin,” Smith said. “On the other hand, there are some patients that
find using it helpful for their chronic pain, and it is still
prescribed a fair amount. Like all drugs, there is a risk/benefit
ratio, balancing the toxicity against the positive effects. With all
opioids one of the most important toxicities is overdose and
respiratory depression, and this is true of propoxyphene as well.”
Propoxyphene also is cardiotoxic, meaning that abusing it can cause dangerous cardiac rhythm changes.
“The result is that the safety margin between the effective and toxic
dosages for this drug is narrower than many other pain medications,”
Smith said. “Alternatives to propoxyphene include acetaminophen,
aspirin, nonsteroidal anti-inflammatory drugs like ibuprofen, or low
doses of other opioids.”
Treatment options for chronic pain vary, including the use of many
different types of medications, therapies, interventions and surgeries,
Friday, March 27, 2009