As of 2025, the treatment of COVID-19 has evolved significantly since the start of the pandemic in late 2019. The most popular and widely used medicines for COVID-19 have varied over time based on disease severity, new variants, emerging evidence, and regulatory approvals. While several treatments exist for different stages of the disease, Paxlovid (nirmatrelvir/ritonavir) stands out as the most widely prescribed oral antiviral medicine for COVID-19 globally.
This article will explore Paxlovid in detail, discuss other notable medications, and provide context for how COVID-19 treatment has progressed.
- Introduction to COVID-19 Treatment
COVID-19, caused by the SARS-CoV-2 virus, affects individuals differently — from mild cold-like symptoms to severe pneumonia, acute respiratory distress syndrome (ARDS), and multi-organ failure. The need for effective therapies led to the development and repurposing of several drugs. COVID-19 treatment generally falls into three categories:
Antivirals (to reduce viral replication)
Anti-inflammatory drugs (to control the immune response)
Supportive therapies (like oxygen, fluids, and mechanical ventilation)
Among antivirals, Paxlovid has emerged as a front-runner for outpatient treatment of COVID-19.https://todayliv.com/
- Paxlovid: The Most Popular COVID-19 Medicine
2.1. What is Paxlovid?
Paxlovid is a combination of two drugs: nirmatrelvir and ritonavir. Nirmatrelvir is the active antiviral agent that inhibits the main protease (Mpro) of SARS-CoV-2, a key enzyme the virus uses to replicate. Ritonavir, an older HIV drug, is included not for its antiviral action against COVID-19 but because it slows the breakdown of nirmatrelvir in the liver, allowing it to stay longer and be more effective.
2.2. Mechanism of Action
Nirmatrelvir works by blocking the activity of the viral Mpro protease, which is crucial for processing viral polyproteins into functional units. Without this processing, the virus cannot replicate effectively inside the host cells.
Ritonavir inhibits the cytochrome P450 3A4 enzyme, boosting nirmatrelvir levels in the bloodstream, allowing for effective concentrations with a lower dose.https://todayliv.com/what-is-ceftriaxone-injection-in-cattle-used-for/
2.3. Who Can Use Paxlovid?
Paxlovid is prescribed for:
Adults and some adolescents (12 years and older, weighing at least 40 kg)
Non-hospitalized patients with mild-to-moderate COVID-19
Patients at high risk of progressing to severe disease (e.g., elderly individuals, those with chronic health conditions like diabetes, heart disease, obesity, or immunocompromised status)https://todayliv.com/what-is-ceftriaxone-injection-in-cattle-used-for/
2.4. Efficacy of Paxlovid
Clinical trials and real-world data show that Paxlovid:
Reduces the risk of hospitalization and death by up to 89% when taken within 3–5 days of symptom onset
Remains effective across most SARS-CoV-2 variants, including Omicron and its subvariants, although ongoing mutations require monitoring
Is well tolerated, with common side effects including altered taste, diarrhea, and muscle aches
2.5. Limitations and Considerations
Drug interactions: Ritonavir affects the metabolism of many other drugs. Careful review of the patient’s medications is required to avoid serious interactions.
Renal impairment: Dose adjustment is needed in patients with moderate kidney disease.
Viral rebound: Some patients experience a return of symptoms after finishing the course, though typically mild and self-limiting.
Despite these limitations, Paxlovid remains the most commonly prescribed oral antiviral due to its convenience, early effectiveness, and ability to be used outside hospitals.https://todayliv.com/what-is-ceftriaxone-injection-in-cattle-used-for/
- Other Important Medicines for COVID-19
Though Paxlovid is dominant for outpatient care, other medications are also essential in the treatment landscape, especially in hospitals or special populations.
3.1. Remdesivir (Veklury)
Remdesivir was the first antiviral approved for COVID-19. Administered intravenously, it is used primarily in hospitalized patients or in high-risk outpatients who cannot take oral medications.
Effective in reducing hospitalization when given early
Requires 3-day outpatient infusions (for early treatment) or 5–10 days for hospitalized cases
Not ideal for widespread use due to logistical challengeshttps://todayliv.com/what-is-ceftriaxone-injection-in-cattle-used-for/
3.2. Molnupiravir (Lagevrio)
An oral antiviral alternative to Paxlovid for patients who cannot take it due to drug interactions.
Less effective than Paxlovid (~30–50% reduction in hospitalizations)
Concerns about mutagenicity in early studies, though not confirmed in humans
Used sparingly, primarily as a second-line option
3.3. Dexamethasone
A corticosteroid used in hospitalized patients with low oxygen levels, dexamethasone reduces mortality by suppressing overactive immune responses.
Key component of inpatient COVID-19 protocols
Not useful in early/mild disease and may worsen outcomes if given too early
3.4. Monoclonal Antibodies (mAbs)
Initially promising, mAbs like bamlanivimab and casirivimab/imdevimab lost efficacy against Omicron variants and are no longer widely used. Some newer antibodies like bebtelovimab had brief use but are also largely obsolete due to viral mutations.
3.5. Other Immunomodulators
Tocilizumab and baricitinib are used in severe or critically ill patients to reduce inflammation and improve survival
Often used in combination with steroids in ICU settings
- Global Access and Use of Paxlovid
Since its emergency use authorization by the FDA in December 2021, and full approval later, Paxlovid has been distributed to:
Over 100 countries, via direct purchase and global access programs
Low- and middle-income countries via generic production agreements coordinated by the Medicines Patent Pool
Generic versions are now produced by companies in India, Bangladesh, and elsewhere, increasing accessibility.
- Future Outlook
While Paxlovid remains the most popular COVID-19 medicine as of 2025, future changes may include:
Next-generation antivirals with fewer interactions and better resistance profiles
Broad-spectrum antivirals that target multiple coronaviruses
Long-acting prophylactic agents for immunocompromised individuals
Combination therapies to prevent rebound and resistance
Moreover, the role of vaccines and updated boosters continues to reduce the severity of infections, often making treatment unnecessary in mild cases.https://todayliv.com/what-is-ceftriaxone-injection-in-cattle-used-for/
- Conclusion
Among all available medications for COVID-19, Paxlovid remains the most popular and widely used due to its effectiveness in preventing severe disease, ease of use, and relatively favorable safety profile. It is a cornerstone of early outpatient treatment, especially for high-risk populations.
While it’s not a cure-all, and not suitable for everyone, it has significantly reduced the burden of hospitalizations and deaths worldwide. Alongside other therapeutic options and continued vaccination efforts, Paxlovid represents a major step forward in managing COVID-19 as it transitions from a pandemic to an endemic disease.