Veklury (Remdesivir)

What Is Veklury and What Is It Used For?

Veklury (remdesivir) is an antiviral medication that treats COVID-19 by blocking the virus from multiplying inside cells. It is administered as an intravenous infusion in a clinical setting and is approved for adults and children who are at least 4 weeks old and weigh at least 3 kg.

The active ingredient in Veklury is remdesivir, a nucleotide prodrug originally developed as part of broad-spectrum antiviral research. When administered, remdesivir is metabolized inside cells into its active form – a nucleoside triphosphate analogue. This active metabolite competes with the natural building blocks of RNA and, once incorporated into the growing viral RNA chain, causes premature termination. In simpler terms, it tricks the virus’s copying machinery into using a faulty component, which halts viral replication.

COVID-19 is caused by the SARS-CoV-2 coronavirus. The disease can range from a mild respiratory infection to severe pneumonia requiring intensive care. Veklury was one of the first antiviral treatments to receive regulatory approval for COVID-19, authorized by the European Medicines Agency (EMA) in July 2020 and by the U.S. Food and Drug Administration (FDA) in October 2020. It remains an important treatment option, particularly for patients requiring hospital care.

Veklury is indicated for two primary patient populations. The first group includes hospitalized patients who have developed pneumonia and require supplemental oxygen – whether low-flow or high-flow oxygen, or non-invasive ventilation – but who are not on invasive mechanical ventilation at the start of treatment. The second group comprises non-hospitalized patients who do not need supplemental oxygen but are at increased risk of progressing to severe COVID-19, such as those with underlying health conditions, advanced age, or immunocompromise.

What Should You Know Before Taking Veklury?

Before receiving Veklury, inform your healthcare provider about any kidney problems, immune system conditions, allergies, pregnancy, or breastfeeding status. Veklury must not be used if you are allergic to remdesivir or any of its other ingredients.

Contraindications

Veklury must not be administered to patients who are allergic (hypersensitive) to remdesivir or to any of the excipients contained in the formulation, including sulfobutylbetadex sodium. If you have previously experienced an allergic reaction to remdesivir, inform your healthcare provider immediately, as re-exposure could trigger a more severe reaction.

Warnings and Precautions

Several important considerations apply before and during treatment with Veklury. Your healthcare team will evaluate these factors to ensure your safety throughout the course of therapy.

Kidney function: Patients with kidney problems require careful monitoring. Each 100 mg dose of Veklury contains 3 g of sulfobutylbetadex sodium (6 g in the loading dose), a cyclodextrin excipient that is renally cleared. In patients with impaired kidney function, this excipient may accumulate. Your doctor may order kidney function tests before and during treatment to ensure renal safety.

Immunocompromised patients: If you have a weakened immune system – whether from a medical condition, organ transplantation, or immunosuppressive medications – your doctor may monitor you more closely. Immunocompromised patients may have a reduced response to antiviral therapy, and treatment effectiveness should be carefully evaluated.

Infusion-related reactions: Veklury can cause hypersensitivity reactions during or after the infusion, including rare cases of anaphylaxis (a sudden, life-threatening allergic reaction). Signs and symptoms to watch for include:

• Changes in blood pressure or heart rate
• Low blood oxygen levels
• High body temperature (fever)
• Shortness of breath or wheezing
• Swelling of the face, lips, tongue, or throat (angioedema)
• Rash, nausea, vomiting, sweating, or chills

Blood tests: Your healthcare provider may order blood tests before starting Veklury and at intervals during treatment. These tests are used to monitor liver enzyme levels (transaminases) and kidney function, allowing your care team to detect any adverse effects early and adjust treatment accordingly.

Pregnancy and Breastfeeding

There is insufficient data to confirm the safety of Veklury during the first trimester of pregnancy. Animal reproductive studies have not demonstrated clear evidence of harm, but human data remain limited. Veklury should only be used during pregnancy if the potential benefits to the mother outweigh the possible risks to the unborn child. Women of childbearing potential should discuss effective contraception with their healthcare provider during treatment.

Remdesivir is excreted into human breast milk in very small amounts. Because clinical experience with remdesivir use during breastfeeding is limited, patients should carefully discuss with their healthcare provider whether to continue or discontinue breastfeeding during treatment. The decision should take into account the importance of the medicine to the mother and the potential exposure to the nursing infant.

Use in Children

Veklury is approved for pediatric patients who are at least 4 weeks old and weigh at least 3 kg. It must not be given to younger or smaller infants, as there is insufficient data to support safe use in this population. Dosing in children is weight-based, with children weighing 40 kg or more receiving the adult dose, and those weighing less than 40 kg receiving adjusted doses calculated per kilogram of body weight.

How Does Veklury Interact with Other Drugs?

Veklury has a limited drug interaction profile due to its intravenous administration and intracellular metabolism. However, chloroquine and hydroxychloroquine must not be taken concurrently, as they may reduce remdesivir’s antiviral efficacy.

Because Veklury is administered intravenously and metabolized intracellularly by hydrolase enzymes, it has relatively few clinically significant drug interactions compared with many oral medications. However, there are important interactions that healthcare providers must be aware of before initiating treatment.

The most critical interaction involves chloroquine and hydroxychloroquine. In vitro studies have demonstrated that these antimalarial drugs can reduce the intracellular activation of remdesivir, potentially diminishing its antiviral activity. For this reason, co-administration is contraindicated, and patients should not receive these medications while being treated with Veklury.

Always inform your healthcare team about all medications you are currently taking, have recently taken, or plan to take. This includes prescription medicines, over-the-counter drugs, herbal supplements, and vitamins. While the interaction profile of remdesivir is relatively narrow, comprehensive medication reconciliation ensures that no unexpected interactions occur.

What Is the Correct Dosage of Veklury?

Veklury is given once daily as an IV infusion. Adults receive a 200 mg loading dose on day 1, followed by 100 mg daily. Treatment lasts 3 days for high-risk non-hospitalized patients or 5–10 days for hospitalized patients with pneumonia.

Veklury is administered exclusively by healthcare professionals in a clinical setting. The drug is given as a slow intravenous infusion over 30 to 120 minutes, once per day. Patients are monitored closely during and after the infusion for signs of adverse reactions.

Adults and Children Weighing 40 kg or More

Children (4 Weeks and Older, Weighing 3 kg to Less Than 40 kg)

Treatment Duration

The duration of Veklury treatment depends on the clinical indication and the patient’s condition:

• Patients with pneumonia requiring supplemental oxygen: Treatment is given daily for at least 5 days. It may be extended up to a total of 10 days if the patient has not shown sufficient clinical improvement.
• Non-hospitalized patients at high risk of severe COVID-19: Treatment is given daily for 3 days. This shorter course must be initiated as soon as possible after COVID-19 diagnosis and within 7 days of symptom onset.

Missed Dose

Since Veklury is administered by healthcare professionals in a controlled clinical setting, it is unlikely that a dose will be missed. However, if a dose is inadvertently skipped or an extra dose is given, patients should inform their nurse or doctor immediately. Healthcare teams will determine the appropriate next steps based on the individual circumstances.

Overdose

There is no specific antidote for remdesivir overdose. In the event of an accidental overdose, supportive treatment should be provided, including monitoring of vital signs and observation of the patient’s clinical status. Because Veklury is only administered under direct medical supervision, the risk of accidental overdose is very low.

What Are the Side Effects of Veklury?

The most common side effects of Veklury include elevated liver enzymes and prolonged blood clotting time (detected via blood tests), as well as headache, nausea, and rash. Serious but rare side effects include infusion-related allergic reactions and sinus bradycardia.

Like all medicines, Veklury can cause side effects, although not everybody gets them. Most side effects are mild to moderate and resolve after the treatment course is completed. Your healthcare team will monitor you during and after each infusion to detect any adverse reactions early.

Elevated transaminases are the most frequently observed laboratory abnormality during Veklury treatment. In clinical trials, these elevations were generally mild to moderate and reversible upon completion of therapy. However, because transaminase elevations can also be caused by the underlying COVID-19 infection itself, your healthcare team will interpret these results in the context of your overall clinical picture.

The prolongation of prothrombin time observed during treatment is also typically mild and clinically insignificant. Nevertheless, patients receiving concurrent anticoagulant therapy should be monitored carefully to avoid additive effects on coagulation parameters.

Reporting of suspected adverse reactions after authorization of the medicine is important. It allows continued monitoring of the benefit-risk balance. Healthcare professionals and patients are encouraged to report any suspected side effects to their national regulatory authority.

How Should You Store Veklury?

Veklury powder does not require special storage conditions before use. Once reconstituted, it must be diluted immediately. After dilution, the solution can be stored for up to 24 hours at room temperature or 48 hours refrigerated.

Because Veklury is administered in a hospital or clinical setting, storage is typically managed by pharmacy staff. However, understanding storage requirements helps ensure medication safety and integrity throughout the supply chain.

Before reconstitution: Veklury 100 mg powder for concentrate for solution for infusion does not require any special storage conditions prior to use. It should be stored out of sight and reach of children. The powder is white to off-white to yellow in color – color variations within this range do not affect the product’s stability or effectiveness.

After reconstitution: Once the powder is reconstituted with sterile water for injection (to produce a 5 mg/mL solution), it must be diluted immediately with 0.9% sodium chloride solution. Do not store the reconstituted concentrate.

After dilution: The diluted infusion solution should ideally be administered immediately. If immediate administration is not possible, the diluted solution can be stored for up to 24 hours at room temperature (20–25°C) or up to 48 hours in a refrigerator (2–8°C). The total time between dilution and administration must not exceed 48 hours.

Expiry date: Do not use Veklury after the expiration date printed on the vial label and carton (marked “EXP”). The expiration date refers to the last day of the stated month. Unused or expired medication should be disposed of in accordance with local regulations – do not discard in household waste or down drains.

What Does Veklury Contain?

Each Veklury vial contains 100 mg of remdesivir as the active ingredient, along with sulfobutylbetadex sodium as a cyclodextrin solubilizer, and pH adjusters (hydrochloric acid and sodium hydroxide). Each dose contains 212 mg of sodium.

Understanding the full composition of Veklury is important for patients with specific allergies or dietary restrictions, particularly regarding sodium content and the cyclodextrin excipient.

Active ingredient: Each single-use vial contains 100 mg of remdesivir. Remdesivir (also known by its research designation GS-5734) is a nucleotide prodrug with the molecular formula C₂₇H₃₅N₆O₈P. It is converted intracellularly to its active triphosphate metabolite (GS-443902), which inhibits viral RNA polymerase.

Other ingredients:

• Sulfobutylbetadex sodium: 3 g per 100 mg dose (6 g in the loading dose). This is a cyclodextrin excipient that acts as a solubilizer, helping remdesivir dissolve properly for intravenous administration. In patients with impaired kidney function (eGFR <30 mL/min), accumulation of this excipient may occur, and the potential benefits of treatment must be weighed against potential risks.
• Hydrochloric acid: Used for pH adjustment
• Sodium hydroxide: Used for pH adjustment

Appearance and packaging: Veklury is supplied as a white, off-white to yellow powder in a clear single-use glass vial. Each carton contains 1 vial. After reconstitution with 19 mL of sterile water for injection, the resulting clear solution has a concentration of 5 mg/mL remdesivir.