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:** FARAD@ucdavis.edu
- **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:** 1-888-873-2723
- **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