Urinary stones are a common illness and account for about 12% of patient visits in urology outpatient departments [1]. The treatment modalities for urinary stones include shock wave lithotripsy (SWL), laparoscopic removal, and percutaneous surgery-all of which are less invasive than open surgery. SWL is noninvasive and does not necessitate general anesthesia or hospital admission. SWL is widely used as a primary treatment of urinary stones because its clinical outcome is good and it can be performed in an outpatient setting [2,3]. Terpene combination (Rowatinex) was developed in the 1950s, and it is known to reduce pain induced by ureteral stones and to increase the spontaneous passage of urinary stones when used in a supportive role. Bak et al. [4] reported that Rowatinex can reduce the frequency of urinary stone pain and significantly increase early spontaneous expulsion of urinary stones. In this study, we evaluated the effect of Rowatinex on the expulsion rate of ureteral stones after SWL.

Group 1 included 147 patients (106 men and 41 women). The mean age of group 1 was 48.32±14.14 years (18-80 years). A total of 352 patients (234 men and 118 women) were not prescribed Rowatinex (group 2). The mean age of group 2 was 48.20±14.46 years (19-84 years). The mean size of ureteral stones was 7.49±3.11 mm in group 1 and 7.25±2.80 mm in group 2 (p=0.317) (Table 1). In group 1, 104 patients (70.7%) had upper ureteral stones, 6 patients (4.1%) had mid ureteral stones, and 37 patients (25.2%) had lower ureteral stones. In group 2, 230 patients (65.3%) had upper ureteral stones, 22 patients (6.3%) had mid ureteral stones, and 100 patients (28.4%) had lower ureteral stones (p=0.425) (Table 1).

Two weeks after the initial SWL, expulsion of ureteral stones was observed in 55 patients (37.4%) in group 1 and in 125 patients (35.5%) in group 2 (p=0.684) (Fig. 1). A total of 319 patients without stone passage were re-evaluated at their third visit 4 weeks after the initial SWL. The age, sex, stone size, and stone location were not significantly different between the two groups (Table 2). The cumulative expulsion rate of ureteral stones in group 1 was higher than that in group 2 (72.2% compared with 61.1%, p=0.022) (Fig. 1). The mean number of SWL sessions was 1.63±0.49 in group 1 and 1.64±0.48 in group 2 (p=0.645). The treatment duration, complications, and number of patients who underwent URS were not significantly different between the two groups (Table 3). Adverse effects occurred after SWL in a total of 74 patients (14.8%): 23 patients (15.6%) in group 1 and 51 patients (14.5%) in group 2 (p=0.783). Five patients in group 1 and nine patients in group 2 experienced hematuria (p=0.422). Acute pyelonephritis occurred in one patient (0.7%) in group 1 and in one patient (0.3%) in group 2 (p=0.503). Fifteen patients (10.2%) in group 1 and 40 patients (11.4%) in group 2 had to undergo URS (p=0.756).

The treatment modalities for ureteral stones are determined based on the size, number, and location of the urinary stones in the urinary tract. Because of recent technological advances in surgical instruments, the treatment of ureteral stones has become more diversified. SWL, open surgery, and URS are widely being performed. Medical expulsive therapy can be applied when the size of the stones is small [6].

After Chaussy et al. [3] introduced SWL for the treatment of urinary stones in 1980, SWL has become the primary treatment modality for urinary stones. SWL is a noninvasive treatment of urinary stones. However, stone expulsion does not occur immediately after SWL; rather, the debris is released slowly for about 1 month. The remnant stones may cause obstruction, recurrent infection, or calculus regrowth [7].

Medical treatment has been proven to be effective at inhibiting stone growth and recurrence of urinary stones [8,9]. Previous studies have reported that Rowatinex can help with the removal of remnant stone after SWL [10]. Rowatinex is an essential oil of terpenic type that consists of pinene (3%), camphene (15%), borneol (10%), anethol (4%), and cineol (3%). Rowatinex is used for the treatment of ureteral stones, kidney stones, renal colic, and other urologic conditions [11-13].

The exact mechanism of action of Rowatinex is not yet fully known. In preclinical experiments, it was confirmed that Rowatinex has antilithogenic, antibacterial, anti-inflammatory, spasmolytic, and analgesic properties [14, 15]. The antilithogenic property, which influences renal oxalate lithogenesis, is important because most urinary stones are composed of calcium oxalate aggregates. Inhibition of remnant stone formation originating after SWL might increase the long-term success rate of SWL [16]. In addition, Rowatinex has shown antibacterial effects against a variety of pathogens [10]. Rowatinex has anti-inflammatory and analgesic properties derived from cineole and anethole, which are important to patients who have urolithiasis with spasm, inflammation, pain, and infection [17,18]. According to Horvath [19], Rowatinex and its single terpenes-such as camphene, cineole, and borneol- have antispasmodic effects on smooth muscle preparations in animal models. Djaladat et al. [7] reported that Rowatinex increases urine excretion by increasing renal blood flow and has antispasmodic effects that may help with the expulsion of renal stone. Engelstein et al. [11], in their prospective, randomized, and double-blind study, showed that the expulsion rate of ureteral stones in the Rowatinex group was greater than that in the placebo group in 87 patients in the emergency room (81% compared with 59%). However, the number of subjects in that study was small, and the authors did not consider stone size and treatment duration. In a randomized trial conducted by Romics et al. [10], the expulsion rate of urinary stones was greater and the treatment duration was shorter in the Rowatiex group than in the placebo group; no significant differences in age, sex, or stone size were found between the two groups. The expulsion rate of urinary stones 2 weeks after the initial SWL was not significantly different between the two groups (37.4% compared with 35.5%, p=0.684). However, 4 weeks after the initial SWL, the cumulative expulsion rate of ureteral stones in group 1 was greater than that in group 2 (72.2% compared with 61.1%, p=0.022). This result indicates that Rowatiex was not effective at stone expulsion in the short term, but was effective over a treatment period of 4 weeks.

This finding may be explained by the properties of Rowatinex, which increases urine excretion and has an antispasmodic effect. The number of SWL sessions and the treatment duration were not significantly different between groups. The occurrence rate of complications after SWL was not significantly different between the two groups (Table 3).

Fifteen patients (10.2%) in group 1 and 40 patients (11.4%) in group 2 underwent URS because of consistent colicky pain or little effect of SWL (p=0.756) (Table 3). Acute pyelonephritis, which may have been induced by SWL, occurred in one patient (0.7%) from group 1 and in one patient (0.3%) from group 2 (p=0.503). Other adverse effects, such as diarrhea, nausea, and vomiting, were not observed.

This study is meaningful because it was a pilot study of the effects of Rowatinex on the expulsion of remnant urinary stone after SWL in Korea. This study had several limitations. First, SWL was not performed by a single operator and the observation period was only 4 weeks. Second, we were unable to routinely analyze the stone components expelled by patients with ureteral stones because it was difficult to retrieve them from the patients. Therefore, we could not determine the relationship between the stone component and the effect of Rowatinex. Third, we did not assess pain; therefore, we could not determine whether Rowatinex reduced colicky pain. Fourth, the analgesic and Tamsulosin prescribed with Rowatinex may have influenced the effects of Rowatinex. Last, the results of this study are based on a retrospective review. Thus, confounding factors and measurement bias were not able to be reduced as much as they could have been in a prospective or randomized study. Additional studies from multiple centers are thus warranted.

Rowatinex was effective at increasing the expulsion rate of ureteral stones 4 weeks after the initial SWL. Rowatinex may increase the long-term success rate of SWL, especially when used for more than 4 weeks without significant adverse effects.