Molnupiravir vs Remdesivir for COVID-19: Outcomes & Failure Factors in Thailand

The treatment landscape for mild-to-moderate COVID-19 continues to evolve, with ongoing research comparing the effectiveness of different antiviral medications. A recent retrospective study conducted at King Chulalongkorn Memorial Hospital in Bangkok, Thailand, investigated the outcomes of patients treated with either five days of oral molnupiravir or three days of intravenous remdesivir. The findings, published in the Chulalongkorn Medical Journal, suggest both treatments remain viable options, though molnupiravir may be associated with faster clinical resolution.

The study, encompassing 182 adult patients diagnosed with COVID-19 during April 2022, revealed a notable difference in treatment failure rates. Treatment failure occurred in 7.8% of the 77 patients receiving molnupiravir, compared to 22.9% of the 105 patients treated with remdesivir (April 2022). This difference was statistically significant (P = 0.007), indicating a lower risk of treatment failure with molnupiravir in this cohort.

Researchers also observed a faster rate of clinical resolution among those treated with molnupiravir. By day 10, 39% of patients in the molnupiravir group had clinically resolved their symptoms, compared to 71.4% in the remdesivir group (P < 0.001). This suggests molnupiravir may lead to a quicker recovery for some individuals.

The study identified certain factors associated with treatment failure. Male gender and the presence of pneumonia at the time of diagnosis were both significantly linked to a higher risk of treatment failure. Researchers found that male patients were 3.375 times more likely to experience treatment failure, while those with pneumonia had a 2.495 times higher risk. The authors recommend close monitoring of COVID-19 patients presenting with pneumonia, regardless of the antiviral treatment chosen.

Importantly, the study reported no deaths or rehospitalizations within 30 days of antiviral therapy in either treatment group. Adverse drug reactions were relatively mild, with headaches or dizziness reported in 3.8% of the remdesivir group and diarrhea in 5.2% of the molnupiravir group. This suggests both medications are generally well-tolerated.

These findings align with a recent meta-analysis published in Immunity, Inflammation and Disease, which found no statistically significant differences in mortality, hospitalizations, viral clearance rates, or time to viral clearance between remdesivir and molnupiravir when used to treat mild-to-moderate COVID-19 outpatients. That analysis, encompassing data from 10 studies and over 5700 patients, did note a lower incidence of adverse events in the remdesivir group (OR = 0.49, 95% CI: 0.26, 0.93).

The Thai study’s conclusion echoes the broader understanding that both molnupiravir and remdesivir remain reasonable treatment options for patients at risk of developing severe COVID-19 symptoms. The choice between the two may depend on individual patient factors and clinical judgment. The availability and route of administration – molnupiravir is oral, while remdesivir is intravenous – also play a role in treatment decisions.

It’s crucial to remember that these findings are based on a retrospective study conducted at a single hospital in Thailand. While valuable, the results may not be generalizable to all populations or healthcare settings. Further research is needed to confirm these findings and to better understand the optimal use of these antiviral medications in diverse patient populations. The meta-analysis highlighted the need for additional studies to more thoroughly evaluate these treatments for COVID-19.

As of February 11, 2026, ongoing research continues to refine our understanding of COVID-19 treatment strategies. The PLATCOV trial, as reported by The Lancet, is evaluating the antiviral efficacy of molnupiravir against ritonavir-boosted nirmatrelvir in patients with early symptomatic COVID-19, adding another layer to the evolving evidence base.