There is significant evidence that Propoxyphene is more dangerous than its alternatives. The study "Co-proxamol overdose is associated with a 10-fold excess mortality compared with other paracetamol combination analgesic" published in 2005 in the British Journal of Clinical Pharmacology states:
When related to prescription volume overdoses involving co-proxamol in
Scotland were 10 times more likely to be fatal (24.6 (19.7, 30.4))
when compared with cocodamol (2.0 (0.88, 4.0)) or co-dydramol (2.4
The excess hazard from co-proxamol is due to inherent toxicity rather
than increased use in overdose. We estimate from this study that
withdrawal of co-proxamol would prevent 39 excess deaths per annum in
There is also strong evidence that the withdrawal in the UK lead to a reduced number of deaths. The article "Effect of withdrawal of co-proxamol on prescribing and deaths from drug poisoning in England and Wales: time series analysis" published in 2009 in BMJ states as a result:
These changes were associated with a major reduction in deaths
involving co-proxamol compared with the expected number of deaths (an
estimated 295 fewer suicides and 349 fewer deaths including accidental
poisonings), but no statistical evidence for an increase in deaths
involving either other analgesics or other drugs.
This translates into more than a hundred deaths due to Propoxyphene per year in the UK, which is similar to the number you quoted if you take the different population sizes into account. The United States have roughly 5 times the population of the UK, which would translate into roughly 2500 deaths over 5 years.
There is also evidence that Propoxyphene is not more effective than alternatives:
On the basis of data on analgesic efficacy and acute safety in both
head to head and indirect comparisons, there is little objective
evidence to support prescribing a combination of paracetamol and
dextropropoxyphene in preference to paracetamol alone in moderate pain
such as that after surgery.
If you have a drug with a questionable safety record that seems to be of limited effectiveness, it makes a strong argument to reconsider the use of this drug entirely.