Is elmiron (pentosan) a better solution than a lidocaine injection?

Takes longer. Elmiron (pentosan) takes about 3 months to start giving you relief from interstitial cystitis symptoms. Typically the other treatment is bladder instillations with a solution of lidocaine, Heparin and sodium bicarbonate. It's the Heparin that actually treats the condition, the other drugs are for symptoms. Heparin instillations work immediately but you'll typically need 8-12 treatments.