Kalium phosphoricum comp. in patients with neurasthenia: a randomized, double-blind, placebo-controlled clinical trial

Abstract

Objective: This Phase IV placebo-controlled clinical trial was designed to demonstrate the efficacy and safety of the product Neurodoron (Kalium phosporicum comp., KPC) in patients with neurasthenia. Methods: This monocenter, randomized, double-blind, placebo-controlled, parallel-group clinical trial (registration number: DRKS00003261) was conducted in an outpatient German trial site. Women and men aged 18 and above were randomized to receive either KPC or placebo if they reported typical symptoms of neurasthenia and a severe psychiatric disorder could be excluded. The primary objectives were a reduction in characteristic symptoms of nervous exhaustion and perceived stress as well as improvement in general health status after 6 weeks of treatment. Results: In total, 204 patients underwent screening, 78 were randomized in each treatment group, and 77 patients each received treatment (intention-to-treat (ITT) population = 154 patients). For none of the primary efficacy variables, an advantage in favor of KPC could be demonstrated in the pre-specified analysis (p-values between 0.505–0.773, Student’s t-test). In a post-hoc analysis of intra-individual differences after 6 weeks treatment, a significant advantage of KPC vs. placebo was shown for characteristic symptoms of nervous exhaustion (irritability (p = 0.020); nervousness (p = 0.045), Student’s t-test). Adverse event (AE) rates were similar between treatment groups, in both groups six AEs were assessed as causally related to treatment (severity mild or moderate). No AE resulted in discontinuation of treatment. Conclusions: Trial treatment was well tolerated with only a few and minor AEs reported, confirming the markedly good safety of KPC. A significant improvement of neurasthenia was seen for the total study population at the end of the treatment period. Superiority of KPC vs. placebo could not be demonstrated with the pre-specified analysis with regards to a sum score of 12 typical symptoms, perceived stress, or general health status. However, the explorative post-hoc analysis revealed that KPC is superior to placebo in the characteristic symptoms irritability and nervousness. KPC could therefore be a beneficial treatment option for symptomatic relief of neurasthenia.