FipDr™ GS-441524 Injectable 20mg/ml

The Standard Concentration — FipDr™'s Most Widely Used FIP Injectable

What This Product Is

FipDr™ GS-441524 20mg/ml is the lowest-concentration injectable formulation in our product range. It contains the same active antiviral compound — GS-441524 — as our 30mg/ml formulation.

The total administered dose (calculated in mg per kg of body weight) remains identical across concentrations.Concentration does not determine efficacy. It determines injection volume — and injection volume determines dosing precision.

Why Concentration Matters for Small Cats

FIP treatment dosing is calculated in mg/kg. In cats weighing less then 2.5 kg, the required dose is higher in absolute terms.

When using higher-concentration formulations, this results in extremely low injection volumes, often approaching the lower limit of accurate measurement with standard syringes.

For example:A 0.05 ml deviation in a 0.1 ml injection represents a 50% dosing error.

In FIP treatment, consistent and accurate dosing over the full 84-day protocol is critical to achieving optimal outcomes:

• Underdosing may delay clinical response and increase the risk of viral persistence

• Overdosing may impose unnecessary physiological stress

The 20mg/ml formulation provides a clinically manageable injection volume, improving dosing accuracy in small cats where precision is essential.

Indicated Cases

This formulation is appropriate for:

• Adult cats weighing less then 2.5 kg

• Kittens diagnosed with FIP

• Cats that have experienced significant weight loss and fall below 2.5 kg

• Cases where precise low-volume dosing is required

This Formulation Is Not the First Choice For

• Cats weighing more then 2.5 kg → the 30mg/ml formulation is more appropriate

• Cases requiring higher-dose protocols → the 30mg/ml formulation is preferred

Clinical Background

GS-441524 is a nucleoside analogue that functions as an inhibitor of RNA-dependent RNA polymerase (RdRp).

Following cellular uptake and intracellular phosphorylation to its active triphosphate form, it is incorporated into viral RNA, leading to premature chain termination and inhibition of viral replication.

Its efficacy in treating FIP was demonstrated in a landmark 2019 study published in Nature (Pedersen et al.), followed by extensive real-world clinical use across thousands of cases globally.

The 20mg/ml formulation contains the same pharmaceutical-grade GS-441524 as all FipDr™ injectable products.Differences in concentration reflect clinical usability and dosing precision, not product quality.

Concentration Selection Guide

Administration

• Route: Subcutaneous injection

• Frequency: Once daily

• Dose: Calculated in mg/kg based on current body weight

• Standard treatment duration: 84 consecutive days without interruption

Dose adjustments should only be made under veterinary supervision.

Early clinical response is typically observed within the first 7 days, including:

• Improved appetite

• Reduction in fever

• Increased activity

If no response is observed within 7 days, further evaluation is recommended before discontinuation.

Quality and Sourcing

FipDr™ injectable formulations are produced to pharmaceutical-grade standards, including:

• Verified API sourcing

• Concentration accuracy testing

• Stability validation

Each batch undergoes quality control prior to release to ensure consistency and reliability.Batch documentation is available upon request for veterinary or compliance purposes.