Potent Inhibition of Biphasic Tubular Reabsorption of Lithium by Acetazolamide and Foscarnet in Rats

Drug interactions of carbonic anhydrase inhibitors and activators

INTRODUCTION

Carbonic anhydrases (CAs, EC 4.2.1.1) have been established drug targets for decades, with their inhibitors and activators possessing relevant pharmacological activity and applications in various fields. At least 11 sulfonamides/sulfamates are clinically used as diuretics, antiglaucoma, antiepileptic, or antiobesity agents and one derivative, SLC-0111, is in clinical trials as antitumor/antimetastatic agent. The activators were less investigated with no clinically used agent.

AREAS COVERED

Drug interactions between CA inhibitors/activators and various other agents are reviewed in publications from the period March 2020 - January 2024.

EXPERT OPINION

Drug interactions involving these agents revealed several interesting findings. Acetazolamide plus loop diuretics is highy effective in acute decompensated heart failure, whereas ocular diseases such as X-linked retinoschisis and macular edema were treated by acetazolamide plus bevacizumab or topical NSAIDs. Potent anti-infective effects of acetazolamide and other CAIs, alone or in combination with other agents were demonstrated for the management of Neisseria gonorrhoea, vancomycin resistant enterococci, Acanthamoeba castellanii, Trichinella spiralis, and Cryptococcus neoformans infections. Topiramate, in combination with phentermine is incresingly used for the management of obesity, whereas zonisamide plus levodopa is highly effective for Parkinson's disease. Acetazolamide, methazolamide, ethoxzolamide, and SLC-0111 showed synergistic antitumor/antimetastatic action in combination with many other antitumor drugs.

Surveillance of drug overdose and identification of its risk factors by a multivariate analysis using the Japanese Adverse Drug Event Report database

BACKGROUND

Limited information is currently available on drug overdose in Japan. Therefore, the present study examined drug overdose using the Japanese Adverse Drug Event Report (JADER) database.

METHODS

The records of drug overdose in patients were extracted from the JADER database. Risk factors for drug overdose in patients with bipolar disorders were examined using a multiple logistic regression analysis.

RESULTS

Overdoses of 1327 medicines in 784 patients were registered in the JADER database. An overdose of lithium carbonate was the most frequently reported in 144 patients, followed by zolpidem tartrate in 88, and then quetiapine fumarate, sodium valproate, risperidone, and paroxetine hydrochloride hydrate. The number of overdoses was higher in females, and peaked in patients aged with 30-39 years. The dosages of overdosed lithium carbonate ranged between 1800 and 60,000 mg, with a median of 8400 mg, while those of overdosed zolpidem tartrate ranged between 15 and 600 mg, with a median of 105 mg. Forty-one drug overdose cases were registered in 3521 patients with bipolar disorder, bipolar I disorder, or bipolar II disorder in the JADER database. A multivariate analysis of these cases identified female sex, an age younger than 50 years, and the use of lithium carbonate as risk factors for drug overdose. Lamotrigine reduced its odds, and no relationship was observed with aripiprazole or sodium valproate.

CONCLUSION

The present study represented a surveillance of drug overdose, and identified risk factors in patients with bipolar disorders by a multivariate analysis using the JADER database.

Analysis of sex difference in the tubular reabsorption of lithium in rats

Lithium is used in the treatment of bipolar disorder. We previously demonstrated that two types of transporters mediate the tubular reabsorption of lithium in rats, and suggested that sodium-dependent phosphate transporters play a role in lithium reabsorption with high affinity. In the present study, we examined sex differences in lithium reabsorption in rats. When lithium chloride was infused at 60 µg/min, creatinine clearance and the renal clearance of lithium were lower, and the plasma concentration of lithium was higher in female rats. These values reflected the higher fractional reabsorption of lithium in female rats. In rats infused with lithium chloride at 6 µg/min, the pharmacokinetic parameters of lithium examined were all similar in both sexes. The fractional reabsorption of lithium was decreased by foscarnet, a representative inhibitor of sodium-dependent phosphate transporters, in male and female rats when lithium chloride was infused at the low rate. Among the candidate transporters mediating lithium reabsorption examined herein, the mRNA expression of only PiT2, a sodium-dependent phosphate transporter, exhibited sexual dimorphism. The present results demonstrated sex differences in the tubular reabsorption of lithium with low affinity in rats.