Plasma concentrations of lidocaine resulting from instillation of lidocaine jelly into genitourinary tract prior to cystoscopy.

Plasma concentrations of lidocaine were measured over a period of three hours following the instillation of lidocaine jelly (Xylocaine 2% Jelly) into the genitourinary tract of 30 patients (15 male, 15 female) scheduled for cystoscopy. The mean quantity of jelly instilled was 21.4 Gm (11-27.5 Gm) and of lidocaine HCl administered thereby 428 mg (218-550 mg). Plasma concentration reached measurable levels in only 5 cases, never exceeding 0.2 microgram/ml.