This morning, I attended the concurrent session on the evidence-based cutaneous treatment of nausea, pain, and neuropathy. This was overall a good session, although it reinforced the need for more research in this area since some of what we are practicing in this area is not highly evidence-based. Some of the salient points:
Cutaneous treatment of nausea:
- N/V represents a common reason for PC consultation and admission, and is one of the most common admissions for ‘hospice failure’
- We should have clinical practice guidelines since they reduce practice variation and may lead to better less costly care at the end of life
- Topical gels are widely used in ~60% hospice pts; Advantages- known and inexpensive (eg NSAIDS for arthritis). Disadvantages – limited data about absorption and effectiveness of other commonly used gels (lorazepam, benadryl, haloperidol)
- ABH (ativan, benadryl, haldol) gel guideline formation would be helpful.
- However, there is no data showing that any of the drugs are absorbed from the skin in patients in therapeutic amounts
- There was a paper by Bleicher, et al in 2008 – improved nausea, vomiting- but retrospective, no control group, other agents allowed.
- ABH is <$1 a dose . If it works- great- could possibly avoid admission for symptom control, if not, admission for N/V might mean $2500/5 days
- Study ongoing to collect pilot data on absorption of ABH gel.
- Take home point: data for absorption and utility of ABH gel is limited, prelim evidence shows absorption is poor, and more research in this area is needed (and some recent efforts to obtain funding on this topic have been less successful)
Cutaneous Absorption of Morphine
- Recent paper in J pain symptom mgmt (JPSM) – Judith Paice, March 2008: “Morphine bioavailability from a topical gel formulation in volunteers” – she noted in her experience that providers were using topical morphine, but since the drug is not lipid soluble , she asked whether there is really any evidence that this is absorbed?
- Some studies of topical morphine delivered to open skin ulcers– there is some bio-availability (Ribero JPSM 2004)… but does it impair wound healing?
- For this study, Judith Paice compounded a morphine gel formulation with PLO matrix applied to wrist
- Randomized, placebo controlled, small sample of healthy volunteers, studied the topical morphine alongside SC morphine
- SC – showed 100% bioavailability
- Topical – showed very very low Cmax, bioavailability -> N/A (All plasma samples obtained after topical morphine admin had either no detectable morphine present or something below the limit of quantification)
- Take home points: Bioavailability of morphine when administered SC is consistent with what we arleady know, and morphine is a poor candidate for transdermal drug delivery (at least, on INTACT skin)
Speaker #3 discussed other SC and IV medications for treatment of nausea, and consider checking the handout for this discussion since many medications were mentioned- too many to list here!
Overall this was a great seminar and the speakers illustrated the need for continued evidence-based studies for our practice patterns, and hopefully these will lead to development of clinical guidelines.
Aaron Olden, MD
University of Rochester Faculty