farad-withdrawal

name	farad-withdrawal
description	Access FARAD (Food Animal Residue Avoidance Databank) for drug withdrawal recommendations in food-producing animals. Covers meat, milk, and egg withdrawal intervals including extralabel use guidance.

FARAD Withdrawal

Overview

FARAD (Food Animal Residue Avoidance Databank) is the federally funded resource for drug withdrawal interval recommendations in food-producing animals. Maintained by UC Davis School of Veterinary Medicine, FARAD provides evidence-based guidance for both FDA-approved label withdrawals and extralabel drug use (ELDU) withdrawal determinations when commercial withdrawal data is unavailable.

What is FARAD?

Definition: Database and consultation service that provides withdrawal interval recommendations to ensure food animal products (meat, milk, eggs, honey, aquaculture) are safe for human consumption.

Regulatory Authority:

• Established under AMDUCA (Animal Medicinal Drug Use Clarification Act)
• Endorsed by FDA CVM, USDA-APHIS, state veterinary boards
• Primary resource for veterinarians determining ELDU withdrawal times
• Non-regulatory (advisory); veterinarian makes final determination

What FARAD Provides:

• Withdrawal time recommendations (in days for meat, hours for milk, days for eggs)
• Pharmacokinetic basis and safety margins
• Relevant literature citations
• Species-specific calculations
• Conservative ("extra-safe") vs. standard margin options
• Written recommendation documentation for veterinary records

Contact Information

Phone Consultation:

• Primary Line: 1-888-873-2723 (1-888-USFARAD)
• Hours: Monday-Friday, 8:00 AM - 4:30 PM Pacific Time
• Wait Time: Typically 24-48 hours for response (urgent cases prioritized)

Email Submission:

• Email: [e-mail]
• Turnaround: 2-3 business days for written response

Online Database:

• Website: https://www.farad.org
• Search Field: Can query commonly used drugs with pre-calculated withdrawals (convenience lookup)
• Not All Drugs: Limited to most frequently used compounds; custom consultations needed for novel drugs

Fax (legacy):

• Available for formal submission; phone/email preferred

Species Covered by FARAD

Primary (Most Comprehensive Data):

• Beef cattle
• Dairy cattle
• Swine
• Poultry (chickens, turkeys)
• Sheep
• Goats

Secondary (Limited Data Available):

• Horses
• Aquaculture (farmed fish: salmon, catfish, trout)
• Rabbits
• Fur-bearing animals (minks)

Not Covered:

• Wildlife (deer, elk, wild boar - typically no withdrawal recommendations provided)
• Companion animals (dogs, cats) - not food-producing; different regulatory framework

When to Consult FARAD

Mandatory FARAD Consultation:

1. Extralabel Drug Use (ELDU): Drug is being used off-label (species, dose, route, or indication) and NO withdrawal time is on the FDA-approved label
2. Compounded Drug: Compounded formulation has no standard withdrawal data
3. Novel Drug Combination: Multiple drugs given concurrently; unknown interaction on withdrawal time
4. Accidental Exposure: Animal exposed to prohibited substance (e.g., avermectin to dairy cow); need emergency withdrawal guidance

Recommended FARAD Consultation:

• Aminoglycoside use in dairy (complex pharmacokinetics; kidney residue concentration)
• First-use of unfamiliar drug in food animal
• Pediatric/geriatric animals where metabolism differs from standard (very old cattle with renal disease, neonatal animals)
• Suspected drug interaction affecting residue depletion

Not Necessary:

• FDA-approved label withdrawal time is specified (use label without consultation)
• Companion animal drug use (dogs, cats, birds - non-food)
• Human medication used off-label in non-food animals

What FARAD Provides in Recommendation

Standard FARAD Written Recommendation Includes:

1. Header Information:

   • Date of recommendation
   • Consulting veterinarian name and contact
   • Drug name (generic + brand)
   • Species (beef, dairy, swine, etc.)
   • Target animal weight/age (if relevant)

2. Dose & Administration:

   • Specified dose (mg/kg or total dose)
   • Route of administration (PO, IV, IM, intramammary, feed)
   • Frequency (once daily, twice daily, single injection, etc.)
   • Duration of treatment (days)

3. Withdrawal Recommendations:

   • Meat Withdrawal: Number of days between last dose and slaughter/harvest for human food
   • Milk Withdrawal: Number of hours between last dose and milk collection for human consumption
   • Egg Withdrawal: Number of days for egg withdrawal (poultry only)
   • Tissue Specificity: If organ meats have different withdrawal (e.g., liver vs. muscle)

4. Safety Margin Designation:

   • Standard Margin: Based on pharmacokinetic data with typical safety buffer (1.5-2x)
   • Conservative/Extra-Safe Margin: Higher safety buffer (2-5x) recommended for:
     • First-time use of drug
     • High-value animals
     • Immunocompromised animals
     • Renal/hepatic impairment

5. Pharmacokinetic Basis:

   • Summary of half-life, clearance rate, tissue distribution
   • How withdrawal time was calculated
   • Assumptions (normal kidney/liver function, standard species physiology)

6. Literature Citations:

   • Published pharmacokinetic studies
   • Previous FARAD consultations if relevant
   • Manufacturer data if available
   • Why certain literature was used vs. alternative studies

7. Special Considerations:

   • Drug interactions if other medications given concurrently
   • Age/weight effects if non-standard
   • Disease state effects (renal/hepatic impairment = longer withdrawal)
   • Regional/market considerations (some countries stricter than US)

Regulatory Framework: AMDUCA & Withdrawal

AMDUCA Permits Extralabel Drug Use When:

• Veterinarian establishes valid VCPR (client-patient relationship)
• Drug is FDA-approved (for any species or indication)
• No FDA-approved alternative exists or is unsuitable
• Veterinarian determines safe withdrawal interval
• Extra-label use is documented in medical record

Veterinarian Responsibility:

• Final determination of withdrawal time belongs to prescribing veterinarian (not FARAD, not pharmacist)
• FARAD provides evidence-based recommendation; veterinarian may choose more conservative interval if justified
• Withdrawal time must be documented in animal medical record and communicated to client
• Veterinarian liable if withdrawal time is violated (residue in food = public health violation)

Client Responsibility:

• Client (producer) must adhere to withdrawal interval
• Cannot slaughter/milk/egg collect until withdrawal has elapsed
• Client must track withdrawal dates (typically calendar notation, tags on animal pens)
• Violation results in carcass/product condemnation and potential legal action

Common Extralabel Drug Withdrawal Examples

Drug	Species	Indication	Label Status	FARAD Recommendation
Doxycycline IV	Cattle	Pneumonia	Oral approved only	3-5 days meat (conservative)
Sildenafil	Horse	Pulmonary hypertension	No approval	5-7 days (experimental; consult for specific case)
Albuterol IV	Swine	Respiratory	Feed-based approved	1-2 days (IV is extra-label)
Tramadol	Poultry	Pain	No approval	5-7 days eggs (contact FARAD; rarely available)
Acyclovir	Cattle	Viral infection	No approval	May not be available (novel antiviral)

How to Submit a FARAD Request

Telephone Request (Fastest for Emergency):

1. Call 1-888-873-2723
2. Describe animal, disease, drug name/dose/route/frequency
3. Provide species, approximate weight, health status
4. FARAD consultant provides verbal recommendation immediately or within 24 hours
5. Document in medical record

Email/Online Submission:

1. Go to https://www.farad.org
2. Click "Submit a Consultation"
3. Complete form:
   • Your contact information
   • Consulting veterinarian name/license #
   • Animal species, weight, age, health status
   • Drug name (generic + brand), dose, route, frequency, duration
   • Indication (disease/condition being treated)
   • Reason for extralabel use (label not available, unsuitable dose, etc.)
   • Any concurrent medications
4. Submit; FARAD responds via email in 2-3 business days

Written Documentation Requirements:

• VCPR established (client-patient relationship documented)
• Clear justification for extralabel use
• Specific drug + dose + route + frequency + duration
• Target withdrawal product (meat, milk, egg)
• Any comorbidities affecting metabolism

Using FARAD Online Database Search

Searchable Field (Limited Database):

• Drug name (generic or brand): "doxycycline", "amoxicillin", "flunixin"
• Species: "beef cattle", "dairy cattle", "swine", "poultry"
• Pre-calculated withdrawal times for most-used compounds
• NOT a complete database; novel drugs/combinations require consultation

Search Steps:

1. Go to https://www.farad.org
2. Navigate to "Database Search"
3. Enter drug name + species
4. View pre-calculated withdrawal times if available
5. If not found: submit custom consultation

Safety Margin Interpretation

Standard Safety Margin (1.5-2x):

• Withdrawal time = (mean time to residue <tolerance) × 1.5-2
• Suitable for: standard animals, normal renal/liver function, single drug use
• Risk: if pharmacokinetics slightly slower than assumed, residue may remain above tolerance

Conservative/Extra-Safe Margin (2-5x):

• Withdrawal time = (mean time to residue <tolerance) × 2-5
• Suitable for: first-use, high-value animals, immunocompromised, renal/hepatic impairment, critical food safety
• Lower risk of residue violation; longer withdrawal period requires client compliance planning

Example: Drug X residue depletes below tolerance in 10 days in healthy animal.

• Standard margin recommendation: 15 days
• Conservative margin recommendation: 20-25 days
• Veterinarian may choose either based on clinical judgment and client compliance capability

Limitations of FARAD Recommendations

• Pharmacokinetic Assumptions: Based on normal animal; disease (renal failure, hepatic disease) alters clearance (veterinarian may extend withdrawal)
• Tissue Distribution Variation: Some drugs concentrate in specific tissues (kidney, liver); standard calculations may not account for organ-specific withdrawal
• Novel Drug Combinations: FARAD may lack data; may recommend extra-conservative margin or defer to veterinary literature
• Regional Variation: Some countries have different tolerances; FARAD primarily addresses US FDA tolerances
• Limited Data for Exotic Species: Horses, aquaculture, rabbits have fewer pharmacokinetic studies; may recommend longer withdrawal or suggest literature review
• Client Compliance: FARAD recommendation is only as good as producer adherence; veterinarian must verify tracking and enforcement

Integration with Veterinary Practice

Workflow:

1. Treat food animal off-label
2. Call FARAD immediately or within 24 hours
3. Document FARAD recommendation in medical record with date/time of consultation
4. Communicate withdrawal end date to client in writing (calendar, tag on animal pen)
5. Verify at slaughter/milk pickup that withdrawal has elapsed
6. Document final product disposition (sold, held, destroyed if violated)

Medical Record Documentation:

Date: 2024-03-18
Animal: Dairy cow #42, Holstein, 500 kg
Diagnosis: Clinical mastitis
Treatment: Ceftiofur IV 1 g daily × 3 days (ELDU - no label approval for IV)
FARAD Consultation: 888-873-2723, consulted 3/18/2024
FARAD Recommendation: 7 days meat withdrawal, 24 hours milk withdrawal (standard margin)
Withdrawal End Date: 3/25/2024 for meat; 3/19/2024 for milk
Client Notified: Yes, verbally + written instruction sheet

Sources

• FARAD Website: https://www.farad.org
• FARAD Phone: [phone]
• AMDUCA Guidance (FDA CVM): https://www.fda.gov/animal-veterinary/guidance-documents
• UC Davis School of Veterinary Medicine: Hosts FARAD
• Plumb's Veterinary Drug Handbook (current edition): Withdrawal time tables
• Approved Animal Drug Products (Green Book): Official label withdrawal times