**DATA EVALUATION RECORD**

**AMITRAZ/106201**

**NONGUIDELINE**

**STUDY TYPE: HUMAN TOLERANCE - ORAL**

**MRID: 43283101**

Prepared for

Health Effects Division

Office of Pesticide Programs

U.S. Environmental Protection Agency

1801 Bell Street

Arlington, VA 22202

Prepared by

Toxicology and Hazard Assessment Group

Life Sciences Division

Oak Ridge National Laboratory

Oak Ridge, TN 37831

Task Order No. 61-2004

Primary Reviewer:

[Clint Skinner, Ph.D., D.A.B.T.]{.underline} Signature:

Date:

Secondary Reviewers:

[H. Tim Borges, Ph.D., D.A.B.T.]{.underline} Signature:

Date:

[Robert H. Ross, M.S., Group Leader]{.underline}

Signature:

Quality Assurance: Date:

[Lee Ann Wilson, M.A.]{.underline} Signature:

Date:

Disclaimer

This review may have been altered subsequent to the contractor=s
signatures above.

Oak Ridge National Laboratory managed and operated by UT‑Battelle, LLC.,
for the U.S. Department of Energy under Contract No. DE‑AC05‑00OR22725.

**EPA Reviewer:** [Pamela M. Hurley, Ph.D.]{.underline} **Signature:**

**Reregistration Action Branch 3, Health Effects Division (7509C) Date**

**EPA Work Assignment Manager:** [Ghazi Dannan, Ph.D.]{.underline}
**Signature:**

**Registration Action Branch 3, Health Effects Division (7509C) Date**

**[TXR#]{.underline}:** 0052737

**Supplemental**

  -----------------------------------------------------------------------
  **DATA EVALUATION RECORD**

  -----------------------------------------------------------------------

**Root TXR: 0011110**

**[STUDY TYPE]{.underline}:** Double Blind Tolerance Study in Humans-
Oral

> Non-Guideline.

**[PC CODE]{.underline}:** 106201 **[DP BARCODE]{.underline}:** N/A

**[SUBMISSION NO.]{.underline}:** N/A

**[TEST MATERIAL (PURITY)]{.underline}:** Amitraz technical, (98.2%
a.i.)

**[SYNONYMS]{.underline}:**
1,5-Di(2,4-dimethylphenyl)-3-methyl-1,3,5-triazapenta-1,4-diene; Baam;
Form­ami­dine, NBmethyl-N\'-2,4-xylyl-N-(N-2,4-xylylformimidoyl)-;
Methyl-bis(2,4-xylylim­ino­methyl)amine; Mitac; Ovasyn; Taktic; Triazid;

**[CITATION]{.underline}:** Cass, L. (1992). T-344, Amitraz: Report of a
double blind tolerance study of amitraz in six adult healthy volunteers.
Simbec Research Ltd., Merthyr Tydfil, Mid Glamorgan CF48 4DR, South
Wales, United Kingdom. Laboratory Project RD 197/20170. June 8, 1992.
MRID 43283101. Unpublished.

**[SPONSOR]{.underline}:** NOR-AM Chemical Co., Little Falls Centre One,
2711 Centerville Road, Wilmington, DE 19808

**[EXECUTIVE SUMMARY]{.underline}:** In a double-blind sequential dosing
oral human tolerance study of Amitraz, (Lot No. not reported, purity
98.2%), 7 adult male volunteers were given encapsulated 0, 0.0625, or
0.125 mg/kg in lactose over three 14-day periods. One volunteer was
withdrawn from the study following development of a rash unrelated to
treatment. The study subjects were 28.17  3.54 years in age and weighed
67.15  3.15 kg. The study was approved by the Simbec Inde­pendent Ethics
Committee and done according to the Helsinki and Hong Kong revisions
(l989). Each dose was administered 30 minutes after breakfast with 150
ml water. Vital signs including: pulse, respiration rate, blood,
pressure and temperature were taken at B1, -0.5, 1, 3, 6, 12, 24, and 36
hours after dosing. ECGs were performed at B1, 1, 3, 6, 12, 24, and 36
hours after dosing and pupil responsiveness and psychomotor performance
were evaluated pre-dose and at 2.5 and 8 hours after dosing. Urine was
collected at 0-36 hours and 36-60 hours after treatment and blood for
clinical chemistry and hematology was collected prior to the start of
the study and 36 hours after each phase of the study.

Two subjects reported tiredness, pre-dose (0.125 mg/kg) for 9 and 8h
respectively, but this was determined to be unrelated to treatment.
Vital signs and ECG parameters were within normal limits. No clinically
significant changes were seen in pupil response. Psychomotor performance
results showed no significant differences between pre- and
post-treatment. One subject had a slightly elevated total bilirubin at
the post-study screen but it returned to normal limits within three
weeks completion of the study. No treatment-related effects were found
on hematology or urinalysis parameters.

This oral toxicity study in humans is **Acceptable/Nonguideline** and
satisfies the intent of the study.

**[COMPLIANCE]{.underline}:** Signed and dated GLP, Quality Assurance,
and Data Confidentiality statements were provided.

**I. [MATERIALS AND METHODS]{.underline}:**

**A. [MATERIALS]{.underline}:**

  -------------------------- ------------------ ----------------------------------------------------
  **1. [Test                                    Amitraz
  material]{.underline}:**                      

                             **Description:**   white crystalline powder

                             **Lot/Batch #:**   not reported

                             **Purity:**        98.2%

                             **Compound         one year
                             Stability:**       

                             **CAS No. of       33089-61-1
                             TGAI:**            

                             **Structure:**     ![](media/image1.png){width="1.5930555555555554in"
                                                height="1.4083333333333334in"}
  -------------------------- ------------------ ----------------------------------------------------

**2. [Vehicle and/or positive control]{.underline}:** Lactose

  ------------- ------------------- --------------------------------------------------
  **3.                              
  Subjects:**                       

                **Age:**            28.17  3.54 years

                **Sex:**            male

                **Weight:**         67.15  3.15 kg

                **Height:**         1.71  0.05 m

                **Blood Pressure    118.33  7.53
                (Systolic)**        

                **Blood Pressure    73.33  10.33
                (Diastolic)**       

                **Pulse:**          75  6

                **Respirations:**   17  1

                **Temperature:**    36.33  0.29

                **ECG:**            Normal
  ------------- ------------------- --------------------------------------------------

B.  [STUDY DESIGN:]{.underline}

**1. [In life dates]{.underline}**[:]{.underline} Start: January 21,
1992; End: March 4, 1992

2.  [Dose Selection:]{.underline} Previous studies had demonstrated no
    effect at 0.03 mg/kg and sedation at 0.25 mg/kg Amitraz and it was
    estimated that the maximum NOAEL was between 0.06 and 0.25 mg/kg in
    humans. The present randomized double-blind study was designed to
    identify the tolerance of male volunteers to two single doses of
    Amitraz spaced 2-3 weeks apart and determine the NOAEL. The study
    was approved by the Simbec Independent Ethics Committee (20^th^
    Nov. 91) and performed according to the Helsinki and Hong Kong
    revisions (l989).

3.  [Dosing:]{.underline} The study subjects were admitted to the
    clinical pharmacology unit the evening before dosing and remained
    fasting until the next morning. They remained in the unit until 36
    hours after each dosing phase. No concomitant medication, alcohol,
    or drugs of abuse were allowed during the study. Each study subject
    received sequential single oral doses of Amitraz (encapsulated
    0.0625 or 0.125 mg/kg in lactose) with a placebo (lactose) control.
    Each dose was given 30 minutes after breakfast with 150 mL of water.
    In Phase 1 of the study, 4 subjects received placebo and 2 received
    0.0625 mg/kg Amitraz. During Phase 2 conducted 14 days after Phase
    1, two subjects received placebo, two subjects received the low
    dose, and two subjects received the high dose. In Phase 3 (14 days
    after Phase 2) three subjects received placebo and four subjects
    received the high dose. The research was designed so all subjects
    received placebo, low-dose, and high-dose during the course of the
    study.

4.  [Observations:]{.underline} On the morning of dosing during each
    phase of the study, the pulse, respira­tion rate, blood pressure, and
    temperature of each subject were recorded at -1, -0.5, 1, 3, 6, 12,
    24, and 36 hours. ECGs were done one hour before dosing and at 1, 3,
    6, 12, 24, and 36 hours. Psychomotor performance and pupil
    responsiveness were measured pre-dose and at 2.5 and 8 hours after
    dosing.

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5.  [Hematology and clinical chemistry:]{.underline} Blood was collected
    pre-study, and at 36 hours after each phase of the study. The
    CHECKED (X) parameters were examined.

> **a. [Hematology:]{.underline}**

  ---- ------------------------------- ---- -------------------------------
  X    Hematocrit (HCT)                X    Leukocyte Differential Count

  X    Hemoglobin (HGB)                X    Mean corpuscular HGB (MCH)

  X    Leukocyte count (WBC)           X    Mean corpusc. HGB conc.(MCHC)

  X    Erythrocyte count (RBC)         X    Mean corpusc. volume (MCV)

  X    Platelet count                       
  ---- ------------------------------- ---- -------------------------------

> **b. Clinical chemistry:**

  ---- ------------------------------- ---- -------------------------------
  X    Sodium                          X    Creatinine

  X    Potassium                       X    Urea nitrogen

  X    Bicarbonate                     X    Glucose

  X    Alanine aminotransferase (also  X    Total bilirubin
       SGPT)                                

  X    Aspartate aminotransferase      X    Total protein (TP)
       (also SGOT)                          

  X    Gamma glutamyl transferase      X    Albumin
       (GGT)                                
  ---- ------------------------------- ---- -------------------------------

**6. [Urinalysis:]{.underline}** Urine was collected pre-dose and 0-36,
and 36-60 hours after application for the first phase. The CHECKED (X)
parameters were examined.

  ---- -------------------------------- --- -------------------------------
  X    Specific gravity/osmolality      X   Glucose

  X    pH                               X   Ketones

  X    Protein                          X   Bilirubin

                                        X   Blood/blood cells

                                        X   Urobilinogen
  ---- -------------------------------- --- -------------------------------

7.  [Statistics:]{.underline} Kruskal Wallis one-way analysis of
    variance was used for temporally related changes and Wilcoxon Rank
    Sum was used to determine changes between phases. Critical data
    evaluated included blood pressure, pulse, temperature, respiration
    rate and ECG.

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II. [RESULTS]{.underline}:

> **A. [OBSERVATIONS]{.underline}:**

3.  Adverse Events and Clinical Signs: Two subjects reported tiredness,
    pre-dose (0.125 mg/kg) for 9 and 8h respectively. This was
    determined to be unrelated to treatment. One subject was dismissed
    from the study because of an unrelated skin rash and was replaced.
    All other subjects were reported well following the study.

4.  Physiological Measurements: Vital signs and ECG parameters were
    normal. No clinically significant changes were seen in pupil
    response. Psychomotor performance results showed no significant
    differences between pre- and post-treatment.

5.  [Serum Clinical Chemistry]{.underline}: One subject had a slightly
    elevated total bilirubin at the post-study screen. By three weeks
    after the end of the study, the total bilirubin had returned to
    within normal limits. No other effects of clinical chemistry
    parameters were found.

6.  [Hematology]{.underline}: No treatment-related effects were found.

7.  [Urinalysis]{.underline}: No treatment-related effects were found.

8.  [Drugs of Abuse]{.underline}. No drugs of abuse were detected.

**III. [DISCUSSION]{.underline}** **[AND CONCLUSIONS:]{.underline}**

A.  [INVESTIGATORS= CONCLUSIONS]{.underline}: The investigators
    concluded that Amitraz at doses of 0.0625 mg/kg and 0.125 mg/kg was
    well tolerated with no clinical signs of toxicity including
    hematology, clinical chemistry, pupil responsiveness, eye, and
    psychomotor evaluations. The NOAEL was 0.125 mg/kg.

B.  [REVIEWER COMMENTS:]{.underline} This report has individual data for
    all endpoints and no discrepancies with investigators= conclusions
    were found. The highest dose (0.125 mg/kg) may be considered a NOAEL
    based on the parameters investigated. Previous studies had
    demonstrated a no effect level at 0.03 mg/kg and sedation at 0.25
    mg/kg Amitraz and it was estimated that the maximum NOAEL was
    between 0.06 and 0.25 mg/kg in humans. Literature reported clinical
    signs and symptoms after human exposure to Amitraz include
    drowsiness, loss of consciousness, confused mental state, agitation,
    weakness, headache, vomiting, and malaise (Ellenhorn, M.J. et al
    1997). In a ^14^C Human Amitraz study, many of these symptoms were
    seen at 0.25 mg/kg in two human subjects. In this study no
    complaints or adverse effects were seen at roughly half the dose
    that had sedated subjects and caused nausea in previous studies. The
    psychomotor performance and perhaps pupil responsiveness evaluated
    should be sensitive enough to detect CNS depression and respiratory
    depression. Bradycardia would have been detected with the ECG, blood
    pressure, heart rate and respiration evaluations. Due to human
    variation, this may prove to be a tight bracketing of the no effect
    level.

C.  [STUDY DEFICIENCIES:]{.underline} There are standards for human
    studies and endpoints are chosen, as with animal studies, to cover
    most organ systems plus any known endpoints associated with the
    chemical. In the case of Amitraz, most of the known human effects
    were covered by these investigations and doses were carefully
    chosen. More discussion of known human effects, rationale for
    choosing parameters for evaluation and any known additivity of doses
    and serious effects at higher doses or longer exposure would be
    helpful.

**References:**

Ellenhorn, M. S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn\'s
Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed.
Baltimore, MD: Williams and Wilkins,

1997\. pg. 1730 as Cited in HSDB 2004.