CHOOSING AN OPIOID COMBINATION PRODUCT


David E. Weissman


There are over 50 different opioid combination products, available in a
range of tablet strengths and liquids.  Opioid combination products are
typically used for moderate pain that is episodic (e.g. breakthrough pain)
on a prn basis.  These products contain either acetaminophen, aspirin or
ibuprofen, with an opioid:  codeine (e.g. Tylenol #2-4), hydrocodone (e.g.
Lorcet, Lortab, Vicodin, Vicoprofen), oxycodone (e.g. Percocet, Percodan,
Tylox, Roxicet) or propoxyphene (e.g. Darvocet, Wygesic).   Other
formulations also may contain caffeine and/or a barbiturate.  This Fast Fact
will review information for rationally choosing among the various products.


Intrinsic Analgesic Potency

Milligram for milligram, oxycodone and hydrocodone are the most potent
opioids in this group; they are roughly equianalgesic to each other.
Codeine is less potent and propoxyphene the least potent of the group;
propoxyphene products are probably no more potent than aspirin or
acetaminophen alone.

Toxicity

The dose limiting property of all the combination products is the aspirin,
acetaminophen or ibuprofen, not the opioid (see below).  Patients receiving
any of the four opioids may experience classic opioid side effects: nausea,
constipation, pruritus or sedation, along with the potential for tolerance
and physical dependence with chronic use.  Differences in side effect
severity among the different opioids is largely idiosyncratic; there is
anecdotal experience that codeine is the most, and hydrocodone the least,
emetogenic among the four opioids.   Propoxyphene’s major metabolite is a
CNS stimulant, increasing the likelihood of seizures in an overdose
situation; it is also cardiotoxic, with lidocaine-like effects.   Because of
limited efficacy and increased toxicity, propoxyphene is not recommend,
especially in the elderly.1

Cost

Generic products are readily available and typically much less expensive.

Range of available doses

Codeine products: 15-60 mg codeine/tablet
Oxycodone or hydrocodone: 2.5–10 mg oxycodone/tablet
Propoxyphene; 50-100 mg propoxyphene/tablet
Acetaminophen doses range from 325–750 mg/tablet

Recommendations for use

1. Propoxyphene should rarely, if ever, be prescribed; it should not be used
in the elderly.
2. Prescribe generic products whenever possible.
3. Prescribe only one combination product at any given time; avoid writing
orders that include multiple products; (e.g. “X” for mild pain, “Y” for
moderate pain, etc).  Rather, prescribe only one product, assess efficacy
and toxicity, and modify accordingly.
4. Prescribe codeine, oxycodone and hydrocodone products at a q4h interval;
not q 4-6 or q6h.2
5. Pay very close attention to the total daily dose of
acetaminophen/aspirin/ibuprofen.  Note: the dose of acetaminophen per tablet
can range from 325--750 mg.  Thus, with a recommended limit of < 4 gms per
day, this equals 12 tablets @ 325 mg or 5 tablets @ 750 mg tablet.  Patients
with renal or liver dysfunction are at higher risk for adverse effects from
the non-opioid.3


References

1.  The Management of chronic pain in older persons. AGS panel on chronic
pain in older persons JAGS 1998;46:635-651.
2.  Jacox A, Carr DB, Payne R, et al. Management of Cancer Pain. Clinical
Practice Guideline No. 9. AHCPR Publication No. 94-0592. Rockville, MD.
Agency for Health Care Policy and Research, U.S. Department of Health and
Human Services, Public Health Service, 1994.
3.  Principles of analgesic use in the treatment of acute pain and cancer
pain. American Pain Society, 4th edition.1999.   www.ampainsoc.org
<http://www.ampainsoc.org/>


Edward E. Rylander, M.D.
Diplomat American Board of Family Practice.
Diplomat American Board of Palliative Medicine.