INVESTIGATIVE UROLOGY

Role of papaverine hydrochloride administration in patients with intractable renal colic: randomized prospective trial
Yencilek F, Aktas C, Goktas C, Yilmaz C, Yilmaz U, Sarica K
Department of Urology, Yeditepe University Hospital, Istanbul, Turkey
Urology. 2008; 72: 987-90.

• Objectives: To evaluate the therapeutic effect of papaverine hydrochloride in the treatment of patients with renal colic pain unresponsive to conventional treatment.
• Methods: From March 2007 to January 2008, a total of 561 patients with severe renal colic pain due to a ureteral stone were treated with conventional agents (hyoscine-N-butylbromide and diclofenac sodium) in the emergency and urology departments. Of these 561 patients, 110, with no response to the treatment and persistent severe pain, were randomized into 3 groups for additional treatment. The patients in group 1 (n = 37) received intravenous hyoscine-N-butylbromide, those in group 2 (n = 37) received papaverine hydrochloride, and those in group 3 (n = 36) received pethidine. Before and after treatment, all patients completed a visual analog scale (VAS) questionnaire, with a scale of 0 (no pain) to 10 (maximal complaint), to measure their subjective pain. The mean VAS score of each group was compared with that of the other groups.
• Results: The pretreatment mean VAS scores of all 3 groups were not significantly different statistically from each other (4.02 +/- 1.20, 4.36 +/- 1.97, and 4.27 +/- 1.50; P > .05). However, after treatment, the mean VAS scores of the patients treated with papaverine (0.93 +/- 0.29) and pethidine (0.81 +/- 0.38) were significantly different from those of the hycosine group (3.67 +/- 2.21; P < .001). However, the mean VAS scores of groups 2 and 3 were comparable (P = .67). Unlike opioids, no papaverine-related severe side effects were observed.
• Conclusions: Our results indicate that papaverine hydrochloride can used in an effective manner in the management of renal colic pain in patients unresponsive to commonly used conventional agents.
  
  
• Editorial Comment
  Out of 561 patients with severe renal colic due to ureteral stone treated with hyoscine-N-butylbromide and diclofenac sodium, 110 who did not responded to the treatment were randomized into 3 groups for additional treatment.
  The treatment protocol for these 3 groups consisted of a second repeat dose of intravenous hyoscine-N-butylbromide (20 mg in 250 mL 0.9% physiologic saline) administered within 20 minutes to group 1 (n _ 37); papaverine HCl (60 mg in 250 mL 0.9% physiological saline) administered intravenously within 20 minutes to group 2 (n _ 37); and pethidine (50 mg in 250 mL 0.9% physiologic saline) administered intravenously within 20 minutes to group 3 (n _36). No general side effects associated with hyoscine-Nbutylbromide or papaverine HCl administration was noted. However, a mild degree of bradycardia and hypotension occurred in 2 patients (5.5%) in the pethidine group, as well as mild to moderate degree of sedation in 13 patients (36%). The authors found that the severity of the pain was significantly diminished in the papaverine and pethidine groups (without significant difference between then).
  The authors speculated that smooth muscle relaxation could be accepted as the main factor for papaverine action; nevertheless, the exact underlying mechanism of action could not be derived from the present study. The authors also proposed that possible changes caused by decreased renal output following the renovascular hemodynamic changes could also be responsible for this clinical effect.
  It was concluded that although the classic and established conventional management of renal colic pain is highly effective, before second line opioid application, papaverine administration might be a valuable alternative for these patients.

Dr. Francisco J. B. Sampaio
Full-Professor and Chair, Urogenital Research Unit
State University of Rio de Janeiro
Rio de Janeiro, RJ, Brazil
E-mail: sampaio@urogenitalresearch.org