Intravesical alkalinized lidocaine (PSD597) offers sustained relief from symptoms of interstitial cystitis and painful bladder syndrome

To assess the immediate and sustained relief of the symptoms of interstitial cystitis/painful bladder syndrome (IC/PBlS) after a consecutive 5-day course of treatment with intravesical alkalinized lidocaine (PSD597), and to characterize the pharmacokinetics of single and multiple doses of intravesical PSD597 in a subgroup of patients. In all, 102 adult patients (99 women) with a clinical diagnosis of IC/PBlS were randomized from 19 centres in the USA and Canada to receive a daily intravesical instillation of PSD597 (200 mg lidocaine, alkalinized with a sequential instillation of 8.4% sodium bicarbonate solution, to a final volume of 10 mL) or placebo (double-blind), for 5 consecutive days. Patients were followed at intervals up to 29 days after the first instillation. Efficacy was assessed by changes in the Global Response Assessment (GRA), Likert scales for bladder pain, urgency and frequency, and validated O'Leary-Sant IC symptom and problem indices. Significantly more patients treated with PSD597 rated their overall bladder symptoms as moderately or markedly improved on the GRA scale 3 days after completing the 5-day course of treatment (30% and 9.6%, respectively, for patients treated with PSD597 and placebo; P = 0.012). The treatment effects were also maintained beyond the end of treatment and are further supported by the secondary endpoints, including symptom and problem indices. The peak serum lidocaine concentration during the study was < 2 mu g/mL, and well below the toxic level (> 5 mu g/mL). This preliminary study showed that PSD597 was effective for providing sustained amelioration of symptoms of IC/PBlS beyond the acute treatment phase. The drug was safe, well tolerated and devoid of the systemic side-effects often experienced with oral drug administration. Long-term studies are needed to determine the optimum regimen to maintain this favourable treatment effect.