Remdesivir

BRAND NAMES

• Veklury: The most widely recognized brand of remdesivir, marketed globally by Gilead Sciences. It is used primarily for hospitalized COVID-19 patients.

• Generic Remdesivir: Available in some countries under non-branded or generic names, depending on local regulatory approvals.

• Formulation: Available as a sterile intravenous (IV) solution, intended for hospital administration.

• Purpose: Specifically indicated for treating moderate to severe COVID-19 in patients requiring hospitalization.

MECHANISM OF ACTION

Remdesivir is a prodrug that mimics nucleotides and works by blocking viral RNA replication. Once metabolized in cells, it converts to its active triphosphate form, which competes with natural nucleotides. It binds to RNA-dependent RNA polymerase, causing premature termination of viral RNA synthesis. This mechanism prevents the virus from replicating effectively in host cells. It has demonstrated broad-spectrum activity against several RNA viruses, including coronaviruses.

PHARMACOKINETICS:

Absorption: Remdesivir is administered intravenously, so it bypasses gastrointestinal absorption, ensuring complete bioavailability.

Distribution: It is widely distributed in the body tissues, including the lungs, and is highly protein-bound in plasma (~88–93%).

Metabolism: Remdesivir is metabolized in the liver to its active triphosphate metabolite and other inactive metabolites.

Excretion: The drug and its metabolites are primarily excreted in urine and feces, with a plasma half-life of approximately 1 hour, while the active metabolite persists longer.

PHARMACODYNAMICS

The antiviral activity of remdesivir is concentration-dependent against SARS-CoV-2. It inhibits viral RNA synthesis, limiting viral replication in host cells. This effect reduces viral load and may shorten disease progression. Remdesivir does not directly neutralize the virus but prevents further infection of cells. Its clinical effect is greatest when administered early in the course of infection.

ADMINISTRATION

Remdesivir is administered intravenously, usually starting with a single loading dose followed by daily maintenance doses. It is generally given in a hospital setting under medical supervision. Infusion times range from 30 to 120 minutes, depending on the protocol. Dose modifications may be necessary for patients with kidney or liver impairment, and ongoing monitoring of liver function and potential side effects is recommended throughout treatment.

DOSAGE AND STRENGTH

For adults with COVID-19, the recommended dosage is 200 mg IV on day 1 (loading dose), followed by 100 mg IV once daily for 5–10 days. Pediatric dosing is weight-based for patients ≥3.5 kg. It is available as a 100 mg lyophilized powder or solution for injection. Duration is typically 5 days for moderate cases and up to 10 days for severe cases. Dosage may be adjusted in renal or hepatic dysfunction.

DRUG INTERACTIONS

Remdesivir may interact with strong CYP3A4 inducers, which could reduce its efficacy. Using this medication alongside other hepatotoxic drugs may heighten the risk of liver damage. There are limited data on interactions with anticoagulants or antivirals, so caution is advised. Co-administration with chloroquine or hydroxychloroquine is not recommended due to reduced antiviral activity. Monitoring is essential when given alongside other experimental COVID-19 therapies.

FOOD INTERACTIONS

Remdesivir has no significant known food interactions because it is administered intravenously. Nutritional status does not appear to affect its pharmacokinetics. Patients do not need to fast before infusion. Oral intake of food or supplements does not impact its efficacy. Supportive nutrition may help improve overall recovery during COVID-19 treatment.

CONTRAINDICATIONS

Remdesivir is contraindicated in patients with known hypersensitivity to remdesivir or any component of the formulation. It should be avoided in individuals with severe hepatic impairment (ALT >5 times the upper limit of normal). Caution is required in severe renal impairment (eGFR <30 mL/min). Not recommended in pregnant or breastfeeding women unless benefits outweigh risks. Close monitoring is needed for patients with multi-organ dysfunction.

SIDE EFFECTS

• Nausea – may occur during or after infusion.

• Headache – a common mild side effect.

• Elevated liver enzymes (ALT/AST) – indicates potential liver stress; requires monitoring.

• Infusion-related reactions – such as fever, chills, or shortness of breath during IV administration.

• Hypotension (rare) – drop in blood pressure, especially during infusion.

• Rash or allergic reactions (rare) – can occur in sensitive individuals.

• Shortness of breath or fever – may appear during the infusion process.

• Reversibility – most side effects are mild to moderate and resolve after discontinuation.

• Monitoring – liver function tests should be checked before and during treatment.

OVER DOSE

There is limited experience with remdesivir overdose. Excessive doses may increase the risk of hepatotoxicity, kidney dysfunction, and infusion reactions. Supportive care and monitoring of vital signs and liver/renal function are essential. 

TOXICITY

Remdesivir toxicity is mainly hepatic, with elevated ALT/AST levels reported in clinical trials. Other toxic effects may include renal impairment and infusion-related hypotension. Toxicity is more likely with prolonged use or pre-existing organ dysfunction. Close monitoring of liver and kidney function can prevent serious complications. Most adverse effects are reversible after discontinuation of the drug.