Expression of components of the urothelial cholinergic system in bladder and cultivated primary urothelial cells of the pig

Intravesical sustained release system of lidocaine and oxybutynin results from in vitro and animal study

PURPOSE

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic debilitating condition of unknown etiology. Intravesical lidocaine demonstrated pain relief in patients with IC/BPS. Intravesical oxybutynin has shown therapeutic efficacy in patients with urinary bladder disorders. However, loss of drug with urination requiring multiple administrations and immediate dilution of drug concentration by residual urine in the bladder mitigated intravesical use of both drugs in clinical practice. The aim of this study was to evaluate the efficacy and safety of fixed-dose combination of lidocaine and oxybutynin, forming in the urine a sustained delivery system named TRG-042.

MATERIAL AND METHODS

In-vitro, we have quantitatively tested the concentration of lidocaine and oxybutynin released from TRG-042 in artificial urine. Following the successful in-vitro study weekly formulation of TRG-042 was instilled intravesically to six pigs. All pigs were followed with cystoscopy to assess the gradual degradation of the delivery system and to evaluate bladder response over 7 days. Daily blood samples were tested for drug quantization.

RESULTS

In-vitro studies have demonstrated oxybutynin and lidocaine sustained release over 1-week period coupled with full degradation of the matrix. None of the animals demonstrated any side effects following instillation. Cystoscopy examination observed gradual disintegration of TRG-042 over 1-week with no adverse reaction to the mucosa. Plasma concentrations of oxybutynin and lidocaine were uniformly stable over the 1-week period [1.46 ± 0.176 ng/ml and 4.29 ± 2.48 ng/ml respectively(mean ± SEM)] with almost undetectable concentration of N-desethyloxybutynin (NDO)[0.032 ± 0.068 ng/ml].

CONCLUSIONS

The in-vitro and animal data demonstrated that TRG-042 can safely be used for intravesical sustained release of lidocaine and oxybutynin in the treatment of BPS/IC.

An Unusual Cause of Hemorrhagic Cystitis in a Teenager With Medulloblastoma

Hemorrhagic cystitis is a life-threatening condition in which the transitional epithelium and blood vessels of the bladder necrose leading to severe hematuria, abdominal pain, and voiding lower urinary tract symptoms. Etiology includes chemotherapy (cyclophosphamide, ifosfamide, busulfan), radiotherapy, or infectious agents. We present a pediatric case of a 15-year-old boy with medulloblastoma who developed hemorrhagic cystitis following cisplatin chemotherapy. All other causes were ruled out and it is therefore likely that the agent, in this case, was cisplatin, which has never had hemorrhagic cystitis reported as a side effect. We also suggest a mechanism for urothelial injury centered around OCT-2 receptors.