Famotidine use and quantitative symptom tracking for COVID-19 in non-hospitalised patients: a case series

Abstract

Objective: Treatment options for non-hospitalised patients with coronavirus disease 2019 (COVID-19) to reduce morbidity, mortality and spread of the disease are an urgent global need. The over-the-counter histamine-2 receptor antagonist famotidine is a putative therapy for COVID-19. We quantitively assessed longitudinal changes in patient reported outcome measures in non-hospitalised patients with COVID-19 who self-administered high-dose famotidine orally.

Design: Patients were enrolled consecutively after signing written informed consent. Data on demographics, COVID-19 diagnosis, famotidine use, drug-related side effects, temperature measurements, oxygen saturations and symptom scores were obtained using questionnaires and telephone interviews. Based on a National Institute of Health (NIH)-endorsed Protocol to research Patient Experience of COVID-19, we collected longitudinal severity scores of five symptoms (cough, shortness of breath, fatigue, headaches and anosmia) and general unwellness on a four-point ordinal scale modelled on performance status scoring. All data are reported at the patient level. Longitudinal combined normalised symptom scores were statistically compared.

Results: Ten consecutive patients with COVID-19 who self-administered high-dose oral famotidine were identified. The most frequently used famotidine regimen was 80 mg three times daily (n=6) for a median of 11 days (range: 5-21 days). Famotidine was well tolerated. All patients reported marked improvements of disease related symptoms after starting famotidine. The combined symptom score improved significantly within 24 hours of starting famotidine and peripheral oxygen saturation (n=2) and device recorded activity (n=1) increased.

Conclusions: The results of this case series suggest that high-dose oral famotidine is well tolerated and associated with improved patient-reported outcomes in non-hospitalised patients with COVID-19.

Keywords: COVID-19; COVID-19 symptoms; Famotidine; PROMs; SARS-CoV-2; coronavirus; outpatients.

Figure 1

Symptomatic days before famotidine start. The durations of symptoms prior to starting famotidine are displayed in ascending order for individual patients.

Figure 2

Patient level symptom scores. The longitudinal data for all reported symptoms are shown for individual patients. The mean is indicated as a dashed black line. The baseline scores are indicated adjacent to the y-axis. All patients reported baseline symptoms at 1. Colour-coded lines and dots for respective symptoms are ordered alphabetically and are slightly offset to avoid overlap. Day 0 indicates the day at which patients took the first dose of famotidine. Severity score: 1=not affected, 2=little affected, 3=affected, 4=severely affected. B, baseline; Pt, patient.

Figure 3

Normalised symptom scores of all patients. The mean longitudinal normalised symptom score for all patients is shown. The SE of the mean is indicated. Statistical comparisons by two-sided t-test in comparison with day 0, the day of starting famotidine. *P<0.05; ***p<0.001; ****p<0.0001. NS, not significant.

Figure 4

Patient-level pulse oximetry and activity results. (A) The pulse oximetry data from two patients are displayed. (B–D) The device software provided display of weekly data relating to three metrices recorded using an Oura Ring are displayed for patient 8. The mean for each metric over the displayed period is indicated by a dashed line. Day 0 and week 0 represent the day and week of starting famotidine, respectively. Pt, patient.