The FDA-recommended oral dosage of Elmiron is 100 mg, 2 tablets 2 times a day. Patients may not feel relief from IC pain for the first 2 to 4 months. A decrease in urinary frequency may take up to 6 months. Patients are urged to continue with therapy for at least 6 months to give the drug an adequate chance to relieve symptoms. Hydroxyzine (Atarax).