Tuesday, March 27, 2007
BMJ published a one-pager on dry mouth (xerostomia). Xerostomia, xerostomia, xerostomia. Isn't just a fun word to say? If that is not fun enough for you try these: aptyalism, asialogenesis, asialisis, axerostomasialodesertion (I made the last one up.)
Dry mouth is one of my favorite symptoms. Now I say that it is one of my favorite symptoms, I obviously do not mean that I enjoy having it myself or seeing other people suffering from it. But I do find the symptom very interesting for a few reasons: ubiquity, poorly understood, limited treatments, plenty to educate on, our meds are part of the problem, etc.
Dry mouth is extremely common in the palliative care population, and comes in a range of severity from mildly annoying to very debilitating. Often times the main cause of xerostomia is the medications that we are prescribing to treat other symptoms. Opioids, anti-histamines, anti-psychotics, anti-depressants have all been implicated as contributing to dry mouth. But we have very little evidence for any treatments for dry mouth, so you have to be creative. And it is so common, you would think it would be so easy to study. The only good dry mouth articles were from the dental literature (free pdf here). A search of the palliative literature turned up little.
There is some conflicting anecdotes out there, so maybe some of you Pallimed readers can help clear some of this up by telling us what you advise for xerostomia (giving some evidence where you can).
Artificial saliva: Many articles support it, but staff often don't know about it, and patients find the thought unappealing and when they try it, I have had many patients say they don't really care for it. Do you often prescribe artificial saliva, and if so what brand works best for your patients and in what form (gel, spray, lozenge?)
Cracked lips: Articles encourage use of petroleum jelly, lip balms, carmex, etc to lock in the moisture so that your lips won't crack. But there are some out there who claim any lip balm product may actually exacerbate the problem (although lightly disproved by snopes.com). Most of us know glycerin swabs are out, but some articles I found claimed that a easy saliva substitute is glycerin mixed with water. What do you suggest for cracked lips?
Natural saliva induction using citrus: Some have advocated for pineapple, orange, lemon slices to smell, taste, or chew, but some of the basic science mentions they acidic nature actually causing more harm because of the lack of saliva and the buffering ions. Do you make suggestions about using citrus?
Do you prescribe pilocarpine? I have tried prescribing the eye drops with flavoring added by the pharmacy with minimal improvement of the underlying bitter taste. No patient has been really impressed with the results. I have not gone to Salagen (pilocarpine lozenges) yet, because the few studies I looked at minimally improved salivary output compared to placebo despite costing >$100/month (per HPC Formulary).
Sip water frequently: Makes sense right? Until you look that this may actually reduce the mucus film that builds up from the natural viscosity of saliva. And may increase nocturnal awakening secondary to fluid intake.
Sorry about all these questions, but since there is little out there I thought I would pose some of my clinical dilemmas and get input from the palliative care community. Never thought spit would be so perplexing.
As a bonus question tell us your "favorite symptom." And maybe we'll devote a post to it later.
Picture courtesy of More Altitude via flickr.com