f) Initiation or change in dose of an antidepressant lacking significant cholinergic side effects within the 4 weeks prior to screening (use of stable doses of antidepressants for at least 4 weeks prior to screening is acceptable). g) Use of systemic corticosteroids within 3 months prior to screening. h) Medications with significant cholinergic or anticholinergic side effects (e.g. pyridostigmine, tricyclic antidepressants, meclizine, and oxybutynin) within 4 weeks prior to screening. i) Use of anti-convulsants (e.g. Phenytoin, Phenobarbital, Carbamazepine) within 2 months prior to screening. j) Use of warfarin (Coumadin) within 4 weeks prior to screening.