Investigating the efficacy of melatonin, topical sodium citrate, and multivitamin with zinc as a potential treatment for postinfectious loss of smell

Braz J Otorhinolaryngol. 2024 Nov-Dec;90(6):101496. doi: 10.1016/j.bjorl.2024.101496. Epub 2024 Aug 31.

Abstract

Objectives: Upper respiratory tract infections, including COVID-19, are associated with olfactory dysfunction and there is a need for novel therapeutic approaches. The aim of study was evaluating the effectiveness of adding melatonin, multivitamin and sodium citrate to olfactory training for the treatment of olfactory loss caused by COVID-19.

Methods: We evaluated olfactory function using University of Pennsylvania Smell Identification Test (UPSIT ®) scores and self-reported patient outcomes in post-infectious smell loss cases. We investigated the effectiveness involved olfactory training combined with sodium citrate, melatonin, and multivitamin supplements with zinc over a three-month period compared to an olfactory training alone.

Results: A total of 66 patients were included, with 33 in each group. There was no significant difference in the proportion of participants who showed improvement in UPSIT scores between the groups (OR = 1.43, 95% CI 0.43-4.8, p = 0.56). Both groups showed improvement in average test scores, but there were no significant differences in self-reported olfactory ability or discomfort with olfactory loss. Qualitative symptoms, such as parosmia and phantosmia, were reported by a similar proportion in both groups before and after the treatment (p = 0.11, p = 1, respectively).

Conclusions: Olfactory training alone and olfactory training with associated with melatonin, multivitamins and topical sodium citrate did not show significant differences in improving olfactory function in post-COVID-19 patients.

Keywords: Anosmia; COVID-19; Melatonin; Smell; Zinc.

MeSH terms

  • Administration, Topical
  • Adult
  • Aged
  • COVID-19 / complications
  • Female
  • Humans
  • Male
  • Melatonin* / administration & dosage
  • Melatonin* / therapeutic use
  • Middle Aged
  • Olfaction Disorders* / drug therapy
  • Olfaction Disorders* / etiology
  • Sodium Citrate* / administration & dosage
  • Sodium Citrate* / therapeutic use
  • Treatment Outcome
  • Vitamins* / administration & dosage
  • Vitamins* / therapeutic use
  • Zinc* / administration & dosage
  • Zinc* / therapeutic use

Substances

  • Melatonin
  • Sodium Citrate
  • Zinc
  • Vitamins