In the
past decade, the introduction of anti-inflammatory drops,
gel-forming tear substitutes, new punctal plug designs and a new
appreciation for the importance of omega-3 essential fatty acideour
ability to effectively treat ocular surface disease acids has
enhanced our ability to effectively treat ocular surface disease.
There's never been a time when we've had so many options for patient
care.
But there
are times when we need more than drops. In cases of severe
inflammatory dry eye, it may benefit patients to add an oral
medication.
When Drops Aren't Enough
Sj�gren's
syndrome is characterized by dry eye and xerostomia (dry mouth).
Findings that confirm the diagnosis include lymphocytic
infiltration, apoptosis, alteration of neurogenic control of
secretory function and clinical dryness. Laboratory findings that
demonstrate an autoimmune process include the presence of a positive
autoantibody to SS-A antigen or a confirmatory lip biopsy.
Sj�gren's
may present as an isolated finding, but it's often associated with
systemic autoimmune diseases such as systemic lupus, rheumatoid
arthritis and polymiositis. All of these features confirm the
inflammatory nature of this disease.
The
impairment of neural control may result from the production of
autoantibodies that interfere with muscarinic type 3 acetylcholine
receptors. Secretory dysfunction in Sj�gren's syndrome may occur in
the absence of glandular destruction.
Medication Options
Practitioners have used oral pilocarpine (Salagen) to treat severe
dry eye for years. It's available in 5mg and 7.5mg tablets taken
every eight hours. Papas et al (2004) conducted an 11-center,
256-patient, placebo-controlled study to evaluate the safety and
efficacy of oral pilocarpine (20mg to 30mg daily) for relief of
Sj�gren's-related dry mouth and dry eye. At 12 weeks the pilocarpine
group demonstrated statistically significant improvement in global
assessment of dry eye relief in six of eight related symptoms.
Aragona
et al (2006) evaluated the effect of oral pilocarpine therapy on the
conjunctival epithelium of patients who had Sj�gren's syndrome over
a period of two months. They noted a statistically significant
reduction of burning, foreign body sensation and ocular dryness over
time. Goblet cell density increased 850 percent over a two-month
period. Increase in tear volume was not statistically significant.
They concluded that oral pilocarpine improved signs and symptoms,
but these changes were independent of tear secretion.
Cevimeline hydrochloride (Evoxac) is a muscarinic receptor agonist
that has recently gained popularity in treating Sj�gren's syndrome.
In a multicenter study, Petrone et al (2002) found that Sj�gren's
syndrome patients who took three 30mg doses of Evoxac experienced
substantial improvement in the rate of saliva production and tear
flow when compared to placebo. A 15mg dose afforded less improvement
than the 30mg dose. The number of adverse events in patients
receiving the active drug didn't differ significantly from those in
the placebo group.
Educate about Side Effects
The more
common side effects of cevimeline and pilocarpine include increased
sweating, urinary frequency, flushing, diarrhea and chills. Avoid
prescribing these mediations in patients who are taking
anticholinergic medications as they will essentially negate each
other. One other side effect you should know about is�tearing.