392 Propoxyphene
ings relevant to that question: In a group of 37 rheumatic patients using a
combination pharmaceutical containing propoxyphene, none were abusing the
drug. When a group of 135 hospitalized psychiatric patients received unlim-
ited access to the drug, the level of use roughly correlated with the level of
personality disturbance, but all used it for proper medical purposes. Com-
pared to a general population, hospitalized psychiatric patients should be
more prone to drug abuse, so their lack of interest in propoxyphene is note-
worthy.
Drug interactions. Propoxyphene’s actions can be impeded if a person
smokes tobacco cigarettes. Propoxyphene can lengthen the time span of effects
produced byalprazolamanddiazepam. Studies have found that blood levels
from a dose of the epilepsy medicine carbamazepine will be higher if a person
also takes propoxyphene, possibly high enough to cause harm. Propoxyphene
should be used with particular caution if a person is also usingalcohol,
antidepressants, antihistamines, or tranquilizers. Conceivably the alcohol-
propoxyphene combination could seriously impair driving skills, although sci-
entists testing various mental and physical performance effects of the
combination found that alcohol had more impact than propoxyphene.
Cancer.The drug has been suspected of promoting a form of cancer called
multiple myeloma, but analysis of several hundred sets of medical records
failed to link propoxyphene with the disease.
Pregnancy. Rats with prenatal exposure to propoxyphene have seemed
physically normal but show some abnormal behavior. Studies with hamsters
led an investigator to warn that the drug may cause congenital malformations.
A case report discusses birth defects in a child born to a woman who routinely
used propoxyphene during pregnancy, but we do not know if those malfor-
mations were caused by the drug. Such reports about propoxyphene are rare.
A small survey of medical records found no association between propoxy-
phene and birth defects. The drug passes into a human fetus, and infants born
to pregnant women taking propoxyphene can be dependent on the drug. The
drug passes into human milk but apparently causes no harm to nursing in-
fants.
Additional information.Propoxyphene napsylate (CAS RN 17140-78-2 or
monohydrate form 26570-10-5) is another variety of this drug. Differences be-
tween the hydrochloride version and the napsylate version may lead a medical
practitioner to choose one over the other for a particular patient, but they are
used for the same purposes and have about the same actions. Rat studies
found no evidence that the napsylate form caused birth defects.
Additional scientific information may be found in:“Dangers of Dextropropoxyphene.”British Medical Journal1 (1977): 668.
Jonasson, U., B. Jonasson, and T. Saldeen. “Middle-Aged Men—A Risk Category Re-
garding Fatal Poisoning Due to Dextropropoxyphene and Alcohol in Combi-
nation.”Preventive Medicine31 (2000): 103–6.
Miller, R.R., A. Feingold, and J. Paxinos. “Propoxyphene Hydrochloride: A Critical
Review.”Journal of the American Medical Association213 (1970): 996–1006.
Ng, B., and M. Alvear. “Dextropropoxyphene Addiction—A Drug of Primary Abuse.”
American Journal of Drug and Alcohol Abuse19 (1993): 153–58.