What is Molnupiravir: Uses, Dosage, Side Effects and More

Molnupiravir is an antiviral medication that helps treat COVID-19 in adults who have mild to moderate symptoms. This oral medication works by interfering with the virus's ability to make copies of itself, helping to reduce the severity and duration of your illness.

Think of molnupiravir as a tool that disrupts the virus's reproduction process. When you take it early in your COVID-19 infection, it can help prevent the virus from multiplying as quickly in your body, potentially keeping you out of the hospital.

What is Molnupiravir Used For?

Molnupiravir is specifically designed to treat mild to moderate COVID-19 in adults who are at high risk for severe illness. Your doctor will prescribe this medication if you test positive for COVID-19 and have symptoms that started within the last five days.

The medication works best for people who have underlying health conditions that put them at higher risk for complications from COVID-19. These conditions include diabetes, heart disease, chronic kidney disease, or being over 65 years old.

It's important to understand that molnupiravir is not a prevention medication. You cannot take it to avoid getting COVID-19, and it won't help if you've already been hospitalized with severe symptoms.

How Does Molnupiravir Work?

Molnupiravir belongs to a class of medications called nucleoside analogues, which trick the virus into making mistakes when it tries to copy itself. When the COVID-19 virus enters your cells, it needs to make copies of its genetic material to spread throughout your body.

This medication interferes with that copying process by introducing errors into the virus's genetic code. Think of it like giving the virus faulty instructions so it can't build working copies of itself.

As a relatively newer antiviral medication, molnupiravir is considered moderately effective when taken early in the infection. It's not as strong as some other COVID-19 treatments, but it can still provide meaningful benefits for the right patients.

How Should I Take Molnupiravir?

You should take molnupiravir exactly as your doctor prescribes, typically four capsules twice daily for five days. Take the medication with or without food, but try to take it at the same times each day to maintain consistent levels in your body.

Swallow the capsules whole with a full glass of water. Don't crush, chew, or open the capsules, as this can affect how the medication works in your body.

You don't need to avoid any specific foods while taking molnupiravir, but eating something light before taking it might help if you experience any stomach upset. Many people find it helpful to take the medication with a small snack or meal.

Start taking molnupiravir as soon as possible after your COVID-19 diagnosis, ideally within five days of symptom onset. The medication works best when the virus is still actively multiplying in your system.

How Long Should I Take Molnupiravir For?

The standard treatment course for molnupiravir is exactly five days, taking four capsules twice daily. This means you'll take a total of 40 capsules over the entire treatment period.

It's crucial to complete the full five-day course even if you start feeling better before finishing all the medication. Stopping early might allow the virus to continue replicating and could reduce the medication's effectiveness.

Your doctor will not extend the treatment beyond five days, as studies have shown this timeframe provides the optimal balance of benefits and safety. Taking it longer doesn't improve outcomes and may increase the risk of side effects.

What Are the Side Effects of Molnupiravir?

Most people tolerate molnupiravir well, but like any medication, it can cause side effects. The good news is that serious side effects are uncommon, and most people experience only mild to moderate symptoms.

Here are the most common side effects you might experience while taking molnupiravir:

• Diarrhea, which affects about 1 in 10 people taking the medication
• Nausea or feeling queasy, especially when first starting the medication
• Headache that may feel similar to tension headaches
• Dizziness or feeling lightheaded when standing up
• Fatigue or feeling more tired than usual

These common side effects typically improve as your body adjusts to the medication and usually resolve once you complete the treatment course.

While rare, some people may experience more concerning side effects that require medical attention. These uncommon but serious reactions include:

• Severe allergic reactions with difficulty breathing, swelling of face or throat
• Persistent vomiting that prevents you from keeping the medication down
• Severe diarrhea with blood or signs of dehydration
• Unusual muscle pain or weakness
• Confusion or difficulty thinking clearly

If you experience any of these serious side effects, contact your healthcare provider immediately or seek emergency medical care.

Who Should Not Take Molnupiravir?

Molnupiravir is not safe for everyone, and your doctor will carefully consider whether it's right for you based on your health history and current medications.

You should not take molnupiravir if you are pregnant or might become pregnant during treatment. This medication can potentially harm a developing baby, so reliable contraception is essential during treatment and for four days after your last dose.

Men should also use effective contraception during treatment and for at least three months afterward, as the medication might affect sperm and potentially harm future pregnancies.

People who are breastfeeding should discuss the risks and benefits with their healthcare provider, as it's not yet known whether molnupiravir passes into breast milk.

Your doctor will also be cautious about prescribing molnupiravir if you have severe kidney or liver disease, as these conditions can affect how your body processes the medication.

Molnupiravir Brand Names

Molnupiravir is marketed under the brand name Lagevrio in most countries, including the United States. You might see this name on your prescription bottle or hear your pharmacist refer to it by this brand name.

The medication is manufactured by Merck Sharp & Dohme, and you'll typically receive it as orange and blue capsules in a blister pack designed for the five-day treatment course.

Some countries may have different brand names for molnupiravir, but the active ingredient and dosing remain the same regardless of the brand name on the packaging.

Molnupiravir Alternatives

Several other COVID-19 treatments are available, and your doctor might recommend an alternative based on your specific situation, health conditions, or the severity of your symptoms.

Paxlovid (nirmatrelvir-ritonavir) is another oral antiviral medication that's often considered for mild to moderate COVID-19. It may be more effective than molnupiravir but has more drug interactions and side effects.

For people who cannot take oral medications or have more severe symptoms, intravenous treatments like remdesivir might be recommended in a hospital or infusion center setting.

Monoclonal antibody treatments are also available in some cases, though their effectiveness varies depending on the specific COVID-19 variant causing your infection.

Your healthcare provider will help determine which treatment option is best for your particular circumstances, considering factors like your other medications, health conditions, and symptom severity.

Is Molnupiravir Better Than Paxlovid?

Both molnupiravir and Paxlovid are effective COVID-19 treatments, but they have different strengths and considerations that make one more suitable than the other for different people.

Paxlovid appears to be more effective at reducing hospitalizations and deaths from COVID-19, with studies showing it can reduce the risk of severe outcomes by about 89% compared to molnupiravir's 30% reduction.

However, molnupiravir has fewer drug interactions and may be a better choice if you take multiple medications that could interact with Paxlovid. It's also easier on your stomach for most people.

Paxlovid requires more careful monitoring because it interacts with many common medications, including blood thinners, heart medications, and some antidepressants. Your doctor needs to review all your medications before prescribing it.

The choice between these medications depends on your individual health profile, current medications, and your doctor's assessment of which treatment offers the best balance of benefits and risks for your situation.