Investigation of the impact of urine handling procedures on interpretation of urinalysis findings and product safety in subjects treated with ezogabine

Anti-seizure medications-associated bladder and urethral symptoms: a pharmacovigilance analysis based on the FAERS database

BACKGROUND

In clinical practice, observations have been made regarding bladder and urethral symptoms (BUS), notably urinary frequency and urgency, among patients prescribed the anti-seizure medication (ASM) lacosamide. However, the precise association between ASMs and BUS events in real-world settings remains elusive.

RESEARCH DESIGN AND METHODS

Data from the FDA Adverse Event Reporting System (FAERS) database were employed and the analysis focused on ASMs-associated BUS events utilizing disproportionality analysis methods, including the reporting odds ratio (ROR) and the proportional reporting ratio (PRR). Furthermore, co-administration, time to onset of ASMs-associated BUS events, and severity assessments were conducted.

RESULTS

Several ASMs demonstrated statistically meaningful associations with BUS signals, notably ezogabine, valproic acid/valproate sodium, and clorazepate (p < 0.05). And ASMs-associated BUS events predominantly occurred within the first week and persisted for more than 180 days afterward. Diazepam, gabapentin, and brivaracetam exhibited distinct risk profiles for severe BUS events compared to valproic acid/sodium valproate (p < 0.05). And the nomogram constructed in this study exhibited robust predictive performance.

CONCLUSION

This study yields valuable insights into the association between ASMs and BUS events, but several limitations warrant consideration. Nonetheless, these findings emphasize the significance of vigilance and proactive management of ASMs-associated BUS events.

Kv7 channels a potential therapeutic target in fibromyalgia: A hypothesis

Fibromyalgia is characterized by the primary symptoms of persistent diffuse pain, fatigue, sleep disturbance and cognitive dysfunction. Persistent pain conditions, such as fibromyalgia, are often refractory to current available therapies. An involvement of K⁺ channels in the pathophysiology of fibromyalgia is emerging and supported by drug treatments for this condition exhibiting action at these molecular processes. K⁺ channels constitute potential novel target candidates for pain therapy offering peripheral and/or central actions. The Kv7 channel activators, flupirtine and retigabine, have exhibited pharmacological profiles compatible to the requirements needed for use as a therapeutic approach to fibromyalgia. Clinical trials to address the multidimensional challenges of fibromyalgia with flupirtine and retigabine will provide important insight to the role of K⁺ channels in this condition.

Lack of effect of ezogabine/retigabine on the pharmacokinetics of digoxin in healthy individuals: results from a drug-drug interaction study

Introduction

The potential for ezogabine/retigabine (EZG/RTG) and its N-acetyl metabolite (NAMR) to inhibit the transporter protein P-glycoprotein-(P-gp)-mediated digoxin transport was tested in vitro. EZG/RTG did not inhibit P-gp. However, NAMR inhibited P-gp in a concentration-dependent manner. Based on these in vitro results, NAMR had the potential to inhibit P-gp at therapeutic doses of EZG/RTG (600–1,200 mg/day). As digoxin has a narrow therapeutic index, inhibition of digoxin clearance may have an impact on its safety.

Methods

An open-label, single-center, two session, fixed-sequence study was conducted to assess the effect of co-administration of therapeutic doses of EZG/RTG on digoxin pharmacokinetics in healthy adults. In session 1, subjects received a single dose of digoxin 0.25 mg. In session 2, EZG/RTG was up-titrated over 6 weeks. Digoxin 0.25 mg was co-administered at EZG/RTG steady-state doses of 600, 900, and, based on tolerability, 1,050/1,200 mg/day. Blood samples were collected over 144 hours for determination of digoxin, EZG/RTG, and NAMR concentrations. Urine samples were collected over 48 hours for determination of digoxin concentrations.

Results

Of 30 subjects enrolled, 29 were included in the pharmacokinetic analysis. Compared with digoxin alone, co-administration with EZG/RTG led to small increases in the digoxin plasma area under the concentration–time curve (AUC)_0–120 at doses of 600, 900, and 1,050/1,200 mg (geometric mean ratio 1.08, 90% confidence interval [CI] 1.01–1.15; 1.18, 90% CI 1.10–1.27; 1.13, 90% CI 1.05–1.21, respectively). Safety was consistent with previous repeat-dose studies of EZG/RTG in healthy subjects.

Conclusion

Co-administration of EZG/RTG across the therapeutic range resulted in small, non-dose-dependent and non-clinically relevant increases in digoxin systemic exposure, suggesting that digoxin dose adjustment is not necessary.