How do the cholinergic drugs help dryness in Sjogrens Syndrome?
Patients with SS and significant dryness have 30% to 50% of their glands destroyed by lymphocytic infiltration.
Consequently, the residual functioning tissue can be stimulated to produce more tears and saliva by the use of oral secretagogues.
Pilocarpine (Salagen up to 5 mg QID) and cevimeline (Evoxac up to 30 mg TID) are equally effective compared with placebo.
Cevimeline has a longer half-life (4 hours versus 1.5 hours) and higher specificity for the M3 receptor on lacrimal and salivary glands, resulting in less flushing and diaphoresis. Patients with narrow-angle glaucoma, asthma, or those on beta blockers should avoid these drugs or be monitored closely. Common side effects are sweating, flushing, and GI disturbances (worse with cevimeline).