Pharmacokinetic Comparison of Favipiravir Oral Solution and Tablet Formulations in Healthy Thai Volunteers.

This study compared the pharmacokinetics and safety of favipiravir oral solution with those of tablet formulations, which were agents repurposed to treat nonsevere coronavirus disease 2019 in Thailand. In an open-label, single-dose, randomized, crossover study, 24 healthy subjects under fasting conditions were randomly assigned to a single dose of 200 mg of favipiravir, either as an oral solution of 200 mg/15 mL (test product) or a tablet (reference product), separated by a 7-day washout period. Fifteen plasma samples were collected over 12 hours after drug administration. Plasma favipiravir levels were quantified using in-house developed ultra-high-performance liquid chromatography-tandem mass spectrometry. The test/reference geometric mean ratio along with 90%CI for the maximum plasma concentration, area under the concentration-time curve (AUC) to the time of the last quantifiable concentration, and AUC after single-dose administration, extrapolated to infinity were 115.3% (90%CI, 107.7%-123.3%), 100.4% (90%CI, 96.9%-104.0%), and 100.4% (90%CI, 96.8%-104.2%), respectively. These results were within the predefined acceptance criteria for bioequivalence (80.0%-125.0%). No adverse events were observed in either group. The oral solution formulation could offer the advantage of easier swallowing in broader patient groups.

Transmissibility of SARS-CoV-2 Variants as a Secondary Attack in Thai Households: a Retrospective Study.

Objective: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads through person-to-person contact via small droplet particles, especially in poorly ventilated indoor settings such as households, estimating at 16.6% of secondary attack rate. This study aimed to explore the secondary attack rate in Thai households during the new SARS-CoV-2 variant outbreak. Methods: We obtained a retrospective study of exposed members in households among 30 sets of patients with reverse transcriptase-polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 infection (index cases) at Chulabhorn Hospital, Bangkok, Thailand, from May 1 to June 30, 2021. Characteristic of index cases and households were extracted from medical records and analyzed. Results: The 30 index cases were associated with 157 exposed household close contacts. Seventy-six were RT-PCR confirmed SARS-CoV-2 infections within 14 days after being exposed from an index case, with a secondary attack rate of 48%. However, there was no difference between secondary attack rates among the age of contact, household size, or SARS-CoV-2 variants. Conclusion: Our data show high transmissibility of SARS-CoV-2, which was notably exaggerated compared to previous studies. Therefore, developing preventive strategies such as post-exposure prophylaxis (PEP) in close contact with SARS-CoV-2 infection would be a novel supplement to the current standard of care.