| 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:
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:
- 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
- Compounded Drug: Compounded formulation has no standard withdrawal data
- Novel Drug Combination: Multiple drugs given concurrently; unknown interaction on withdrawal time
- 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:
-
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)
-
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)
-
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)
-
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
-
Pharmacokinetic Basis:
- Summary of half-life, clearance rate, tissue distribution
- How withdrawal time was calculated
- Assumptions (normal kidney/liver function, standard species physiology)
-
Literature Citations:
- Published pharmacokinetic studies
- Previous FARAD consultations if relevant
- Manufacturer data if available
- Why certain literature was used vs. alternative studies
-
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):
- Call 1-888-873-2723
- Describe animal, disease, drug name/dose/route/frequency
- Provide species, approximate weight, health status
- FARAD consultant provides verbal recommendation immediately or within 24 hours
- Document in medical record
Email/Online Submission:
- Go to https://www.farad.org
- Click "Submit a Consultation"
- 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
- 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:
- Go to https://www.farad.org
- Navigate to "Database Search"
- Enter drug name + species
- View pre-calculated withdrawal times if available
- 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:
- Treat food animal off-label
- Call FARAD immediately or within 24 hours
- Document FARAD recommendation in medical record with date/time of consultation
- Communicate withdrawal end date to client in writing (calendar, tag on animal pen)
- Verify at slaughter/milk pickup that withdrawal has elapsed
- 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
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