CaliciX™ Max – High-Potency EIDD-1931 for Severe Feline Calicivirus Disease

1. Active Ingredient

• EIDD-1931 (β-D-N4-hydroxycytidine) – 30 mg

• Active antiviral metabolite

• RNA-dependent RNA polymerase (RdRp) mutagenic nucleoside analogue

2. Pharmacological Class

• Direct-acting antiviral (DAA)

• Broad-spectrum RNA virus inhibitor

• Viral error catastrophe inducer

Active Ingredient

• EIDD-1931 (β-D-N4-hydroxycytidine) – 30 mg per capsule
• Pharmacologically equivalent to ~133 mg of the prodrug form

3. Mechanism of Action

EIDD-1931 is intracellularly phosphorylated to its active triphosphate form and incorporated into viral RNA during replication. This results in:

• Accumulation of transition mutations

• Loss of viral genome integrity

• Suppression of productive viral replication

This mechanism is host-independent, does not rely on viral proteases, and has a high genetic barrier to resistance.

4. Indications

CaliciX™ Max is intended for use in cats with severe or refractory feline calicivirus (FCV)–associated disease, including:

Severe Oral Disease

• Severe Feline Chronic Gingivostomatitis (FCGS)

• Caudal stomatitis with extensive caudal oral inflammation

• Ulcerative stomatitis unresponsive to dental extractions

• Viral glossitis with deep lingual ulceration

• Multifocal buccal, labial, and palatal ulcers

Systemic & Virulent FCV Disease

• Virulent systemic feline calicivirus (VS-FCV)

• FCV-associated fever and lethargy

• Facial and limb edema

• Lameness

• Pneumonia or respiratory compromise

• Hepatic or pancreatic inflammatory involvement

Refractory / High-Risk Cases

• Post-extraction FCGS with incomplete response

• Persistent FCV shedding

• Relapsing disease following corticosteroids or immunosuppressants

• Large-body-weight cats requiring higher antiviral exposure

5. Clinical Signs Targeted

• Severe oral pain

• Drooling (ptyalism)

• Dysphagia and anorexia

• Oral bleeding and ulceration

• Halitosis

• Weight loss and cachexia

• Fever and systemic inflammation

6. Pharmacokinetics

• Good oral bioavailability

• Rapid systemic absorption

• Intracellular activation independent of host viral enzymes

• Distribution into oral mucosa, salivary tissues, and inflamed tissues

• Predictable exposure without reliance on prodrug conversion

Note: Formal feline PK studies for EIDD-1931 are ongoing; dosing is based on translational data and clinical experience.

7. Safety & Precautions

Contraindications

• Pregnancy or breeding animals

• Known hypersensitivity to nucleoside analogues

Use With Caution

• Hepatic impairment

• Renal disease (especially if combined with NSAIDs)

• Long-term use beyond 12 weeks without monitoring

Monitoring Recommendations

• CBC every 2–4 weeks during prolonged therapy

• Liver enzymes (ALT/AST) if combined with other systemic drugs

• Body weight and appetite monitoring

Potential Adverse Effects

• Mild gastrointestinal upset

• Transient lethargy

• Dose-dependent effects with prolonged exposure

8. Drug Interactions

• No known major CYP-mediated interactions

• Compatible with:

  • Analgesics (as directed by your veterinarian)

  • NSAIDs (with renal monitoring)

  • Antibiotics for secondary infection

  • Supportive oral care

9. Regulatory Status

• Not currently licensed for feline use

• Intended for off-label veterinary application under professional supervision

• Use requires informed consent from the animal owner

10. Storage

• Store below 25 °C

• Protect from moisture and light

• Keep in original packaging until use

All orders are processed and dispatched within 24 hours using secure, tamper-evident, and discreet packaging to safeguard product integrity during transit.

We offer fast domestic and international delivery to most destinations across the Europe, GCC, Asia, North America, and South America, with typical delivery times of 2–5 business days.

For destinations that require international shipping, shipments are handled by DHL and FedEx for maximum reliability and tracking accuracy.

Domestic deliveries are fulfilled through trusted local express couriers to ensure prompt arrival.

Definitions of Mild Cases (early ulcers, juvenile gingivitis, mild viral mouth irritation) to Moderate Cases (gingivostomatitis with eating discomfort, drooling, moderate ulceration): Use CaliciX™

Definition of Severe Cases (FCGS, caudal stomatitis, extensive ulceration, severe pain, anorexia): Use CaliciX™ Max

Dosage Instruction:
Below 2.5kg, 1 capsules every 12 hours

2.5 kg ~ 5 kg, 2 capsules every 12 hours

Above 5 kg, 3 capsules every 12 hours

Example 1: Luna weighs 4.5kg, has juvenile gingivitis, with bright red gums.  Use CaliciX™, 2 capsules, ever 12 hours.

Example 2: Spark weights 3.3kg, has stomatitis, and is experience moderate to severe pain.  Use CaliciX™ Max, 2 capsules, ever 12 hours.

Each CaliciX™ capsule contains 15 mg EIDD-1931.

Each CaliciX™ Max capsule contains 30 mg EIDD-1931.

If vomiting occurs within 30 minutes, administer another full dose.

Treatment Duration: 

• Mild: 4–6 weeks
• Moderate: 6–8 weeks
• Severe FCGS: 8–12+ weeks

Adjust dose based on clinical signs
Signs of under-dosing:

• Persistent drooling
• Pain on chewing
• Slow ulcer healing
• Weight loss

Increase dosage within recommended band only under veterinary direction.

Storage: Store in a dry, cool place away from sunlight.

Packaging: 
60 capsules packed in a vacuum-sealed mylar bag.

Expiration: 12 months from production date printed on the package.

Relapse is Possible – Plan for Maintenance

Even with successful initial treatment, 20-30% of cats experience relapses.

Why relapses happen:

• FCV can persist in tissues even after viral suppression
• Stress, illness, or immune system changes can trigger reactivation
• Some cats are genetically prone to chronic FCV

Maintenance strategies to prevent relapse:

Option A: Continuous Low-Dose

• After 12-16 weeks at full dose, reduce to half of previous dosage.
• Continue indefinitely
• Most cost-effective for cats with frequent relapses

Option B: Intermittent Courses

• Stop after 12-16 weeks
• Monitor closely
• At first sign of relapse (mild drooling, reduced appetite), restart 4-6 week course
• Some cats do well with this approach (2-3 courses per year)

Option C: Seasonal/Stress-Triggered

• Some cats relapse during specific triggers (boarding, moving, new pets, illness)
• Use CaliciX™ Max preventively during high-stress periods

Early relapse warning signs:

• Increased drooling (even if mild)
• Slight decrease in appetite
• Pawing at mouth occasionally
• Bad breath returning
• Gum redness reappearing

Act quickly: Restart treatment at first signs = easier to control than waiting until severe relapse.

CaliciX™ Max can generally be used alongside other medications, but be aware:

✅ Safe to combine:

• Antibiotics
• Pain medications
• Appetite stimulants
• Vitamin B12
• Probiotics
• Most chronic disease medications (thyroid, blood pressure)

⚠️ Use with caution (vet supervision required):

• NSAIDs – monitor kidney function closely
• Steroids – can use short-term, but taper as CaliciX™ works
• Chemotherapy drugs – potential additive bone marrow suppression
• Immunosuppressants – may reduce effectiveness of immune response needed to clear virus

❌ Avoid:

• Other nucleoside antivirals – redundant mechanism, increased toxicity risk
• Other experimental antivirals without vet guidance

If your cat is on multiple medications, provide complete list during consultation.

⚠️ EIDD-1931 has potential teratogenic effects (can harm developing kittens).

Absolutely do NOT use in:

• Pregnant queens (any stage of pregnancy)
• Nursing queens (drug may pass into milk)
• Breeding cats attempting to conceive

If your cat is:

• Female and not spayed → spay before starting treatment or ensure no breeding exposure
• Already pregnant → do not use CaliciX™ Max, discuss alternatives with vet
• Nursing → wait until kittens are weaned (8-10 weeks)

Male cats:

• Limited data on effects on sperm/fertility
• Use with caution in breeding males
• Consider temporary contraception if female cats in household