Little is known about morbidity due to drug-related hyponatraemia, despite hyponatraemia being a common side effect of frequently prescribed medicines. We conducted a 12-month retrospective service evaluation of hospital admissions due to drug-related hyponatraemia to determine what drugs are contributing factors, describe patient demographics and burden of morbidity. This was undertaken at a large acute UK hospital and drug-related hyponatraemia was defined by admissions where hyponatraemia was coded as the principal diagnosis and specific medication(s) were recorded as either contributory factor(s) or the principal cause of hyponatraemia and these medication(s) were discontinued. Of 131 hyponatraemia admissions, 71 (54%) were drug-related. Angiotensin converting enzyme inhibitors/ angiotensin receptor blockers, proton pump inhibitors and thiazide diuretics were drug classes most commonly associated. 61% of patients were women, median age 81 (IQR15.5) years, 61% were on more than 2 implicated drugs. The median length of stay was 4 (2-9 days IQR). This study highlights that elderly woman on more than 2 drugs that can cause hyponatraemia, constituted the majority of patients admitted to hospital with drug-related hyponatraemia.

Vaccines have reduced the transmission and severity of COVID-19 but there remains a paucity of efficacious treatment for drug resistant strains and more susceptible individuals. Repurposing existing drugs is a timely, safe and scientifically robust method for treating pandemics such as COVID-19. Here, we review the pharmacology and scientific rationale for repurposing niclosamide, an anti-helminth already in human use as a treatment for COVID-19. In addition to potent antiviral activity, niclosamide has shown pleiotropic anti-inflammatory, antibacterial, bronchodilatory and anticancer effects in numerous pre-clinical and early clinical studies. The advantages and rationale for nebulised and intranasal formulations of niclosamide, which target the site of primary infection in COVID-19, are reviewed. Finally, we discuss the TACTIC-E clinical trial, an international COVID-19 therapeutic platform trial for the use of licensed and novel therapeutic agents, which is investigating niclosamide as a promising candidate against SARS-CoV-2.