Anticoagulant Rodenticides (Oral)
The anticoagulant compounds that are included in this analytical specification are those that are used as rodenticides, mainly in agriculture and urban rodent control. There are two broad chemical categories of these compounds: the hydroxycoumarin derivatives and the indanedione derivatives.

Hydroxycoumarin.jpg
Hydroxycoumarin
Indanedione.jpg
Indanedione
Coumarin anticoagulants were developed during the World War II and these compounds were introduced as effective antithrombotic agents for the treatment of thromboembolic disease in humans. For example, warfarin (an hydroxycoumarin derivative) has been used both as a therapeutic drug and a rodenticide. Several hydroxycoumarin and indandione derivatives have been synthesized and introduced as effective rodenticides; all of these compounds act by interfering with the blood coagulation cascade. These are now considered as first-generation oral anticoagulants.

The appearance of rat strains resistant to warfarin and some other anticoagulant compounds stimulated the development of more potent, second-generation anticoagulants, some of which are also "single dose" compounds and have become known as "superwarfarins" (e.g., brodifacoum, difenacoum and bromodiolone).


Although rodents are the target organisms, non-target vertebrates (including humans) are exposed to rodenticides primarily through consumption of bait and secondarily from consumption of poisoned rodents. As an example, small pellets and whole grain baits are highly attractive to birds. There is also a potential for occupational exposure to these anticoagulant rodenticides during manufacture, formulation and bait application. Since these compounds are not very soluble in water and are not volatile, exposure through drinking water and air, respectively, are rare.


Many anticoagulant rodenticides are known, but it is not the aim of this analytical specification to include each compound. Rather, only those compounds of present analytical interest are included; modifications to this document can be made as it is decided that additional compounds should be included in the analytical panel.

For future reference, below is a list of those first-generation and second-generation anticoagulant rodenticides that have been identified:


First-generation Hydroxycoumarin Derivatives
Coumachlor, Coumafuryl, Coumatetralyl, Warfarin

Second-generation Hydroxycoumarin Derivatives
Brodifacoum, Bromodiolone, Difenacoum, Difethialone, Flocoumafen

First-generation Indanedione Derivatives
Chlorophacinone, Diphacinone, Pindone, Valone

Analyte Names, Trade Names and Structures:
1. Warfarin (trade names as a rodenticide: Athrombine-K®, Biotrol®, Dethmor®, and Sorexa®)
Warfarin Sodium (therapeutic trade name - Coumadin®)
warfarin.jpg
2. Brodifacoum (Some trade names for products containing difenacoum include Folgorat®, Attack Rodenticide Bait®, Final Blox®, Final Rodenticide®, Enforcer®, Ropax®, D-Con®, Havoc®, Klerat®, Talon-G®, and Weatherblok®. Most end-use products contain 0.005% brodifacoum; industrial concentrates of 0.25% are available.)
brodifacoum.jpg
3. Bromodiolone (Some trade names for products containing bromodiolone include Apobas®, Bromard®, Bromatrol®, Contrac®, Deadline®, Morfaron®, Ratimon®, Slaymor® and Topidon®. Most end-use products contain 0.005% bromodiolone).
Bromodiolone.jpg
4. Difenacoum (Some trade names for products containing difenacoum include Ratak®, Neosorexa PP580® and Klerat®. Most end-use products contain 0.005% difenacoum).
Difenacoum.jpg
5. Difethialone (The most common trade name for the product containing this compound is Ratmax®).
Difethialone.jpg
6. Chlorophacinone (Some trade names for products containing this compound include Eaton A-C®, Formula 90®, Enforcer Rat Bait® and Rozol Bait Bites®). Most end-use products contain 0.005% to 0.25% of the active ingredient.)
Chlorophacinone.jpg
7. Diphacinone [aka: Diphenadione, Diphacin, Dipazin, Diphenacin] (Some trade names for products containing this compound include Liquid-Tox II®, Ditrac®, Ramik®, Tomcat® and Promar®).
Diphacinone.jpg

Relevant Chemical Data:

Warfarin:
· Chemical Names: 4-hydroxy-3-(3-oxo-1-phenylbutyl)-2H-1-benzopyran-2-one; 3-(α-acetonylbenzyl)-4-hydroxy-coumarin; 1-(4'-hydroxy-3'-coumarinyl)-1-phenyl-3-butanone; 3-α-phenyl-β-acetylethyl-4-hydroxycoumarin
· CAS No.: 81-81-2
· Molecular formula: C19H16O4
· Molecular weight: 308.32
· Tasteless, odorless, colorless crystals
· Store at room temperature.
· Freely soluble in alkaline aqueous solutions and acetone; moderately soluble in alcohols; and practically insoluble in water, benzene and cyclohexane
· pKa = 5.0
· Partition coefficient: Log P (octanol/water) = 2.6
· Melting Point: approximately 160 °C (purified compound) and 157 °C (technical grade)
· UV Max (aqueous acid) = 270, 280 and 303 nm
· Infra-red Spectrum: principal peaks at wavenumbers 1517, 1599, 1640, 750, 1700, 692 cm-1 (warfarin sodium)
· Mass Spectrum: principal ions at m/z 265, 308, 121, 43, 266, 187, 213, 251


Warfarin Potassium
:
· Chemical Names: potassium 4-hydroxy-3-(3-oxo-1-phenylbutyl)-2H-1-benzopyran-2-one; potassium 3-(α-acetonylbenzyl)-4-hydroxy-coumarin; potassium 1-(4'-hydroxy-3'-coumarinyl)-1-phenyl-3-butanone; potassium 3-α-phenyl-β-acetylethyl-4-hydroxycoumarin
· CAS No.: 2610-86-8
· Molecular formula: C19H15KO4
· Molecular weight: 346.4
· White crystalline powder; discolors on exposure to light
· Store at room temperature (light-protected).
· Soluble in water (1 part to 1.5 parts of water) and in ethanol (1 part in 2 parts of ethanol); very slightly soluble in chloroform and ether


Warfarin Sodium
:
· Chemical Names: sodium 4-hydroxy-3-(3-oxo-1-phenylbutyl)-2H-1-benzopyran-2-one; sodium 3-(α-acetonylbenzyl)-4-hydroxy-coumarin; sodium 1-(4'-hydroxy-3'-coumarinyl)-1-phenyl-3-butanone; sodium 3-α-phenyl-β-acetylethyl-4-hydroxycoumarin
· CAS No.: 129-06-6
· Molecular formula: C19H15NaO4
· Molecular weight: 330.3
· Slightly bitter, white crystalline or amorphous powder; discolors on exposure to light
· Store at room temperature (light-protected).
· Very soluble in water (1 part to less than 1 part of water); freely soluble in ethanol; very slightly soluble in chloroform and ether


Note
: all commercial warfarin preparations are racemic mixtures of the two optical isomers of the drug, i.e., (R)- and (S)-enantiomers.

Brodifacoum
:
· Chemical Names: 3-[3-(4'-bromo-[1,1'-biphenyl]-4-yl)-1,2,3,4-tetrahydro-1-naphthalenyl]-4-hydroxy-2H-1-benzopyran-2-one; 3-[3-(4'-bromo-[1,1'-biphenyl]-4-yl)-1,2,3,4-tetrahydro-1-napthalenyl]-4-hydroxycoumarin
· CAS No.: 56073-10-0
· Molecular formula: C31H23BrO3
· Molecular weight: 523.42
· Off-white to fawn colored, odorless powder
· Melting Point: 228 to 232 °C
· Store at room temperature.
· Soluble in acetone and chloroform; slightly soluble in alcohols and benzene; very slightly soluble in water
(< 10 mcg/mL at 20 °C and pH = 7)


Difenacoum
:
· Chemical Names: 3-(3-[1,1'-biphenyl]-4-yl-1,2,3,4-tetrahydro-1-naphthalenyl)-4-hydroxy-2H-1-benzopyran-2-one; 3-[3-(biphenyl-4-yl)-1,2,3,4-tetrahydro-1-napthalenyl]-4-hydroxycoumarin
· CAS No.: 56073-07-5
· Molecular formula: C31H24O3
· Molecular weight: 444.52
· Crystals from ethyl acetate
· Soluble in organic solvents (e.g., in acetone and chloroform at 50 mcg/mL and in benzene at 600 mcg/mL); very slightly soluble in water (< 10 mcg/mL at 20 °C and pH = 7)


Bromodiolone (Bromadiolone)

· Chemical Names 3-(3-[4'-bromo-[1,1'-biphenyl]-4-yl]-3-hydroxy-1-phenylpropyl]-4-hydroxy-2H-1-benzopyran-2-one; 3-[3-(4'-bromobiphenyl-4-yl)-3-hydroxy-1-phenylpropyl]-4-hydroxycoumarin
· CAS No.: 28772-56-7
· Molecular formula: C30H23BrO4
· Molecular weight: 527.41
· Slightly soluble in water (approximately 19 mcg/mL at 20 °)


Difethialone
:
· Chemical Name: 3-[3-(4'-bromo-[1,1'-biphenyl]-4-yl)-1,2,3,4-tetrahydro-1-naphthalenyl]-4-hydroxy-2H-1-benzothiopyran-2-one
· CAS No.: 104653-34-1
· Molecular formula: C31H23BrO3S
· Molecular weight: 539.48
· Soluble in acetone and chloroform; slightly soluble in alcohols and benzene; very slightly soluble in water (approximately 0.39 mcg/mL at 25 °C)


Chlorophacinone
:
· Chemical Names: 2-[(4-chlorophenyl)-phenylacetyl]-1H-indene-1,3(2H)-dione; 2-[(p-chlorophenyl)-phenylacetyl]-1,3-indanedione
· CAS No.: 3691-35-8
· Molecular formula: C23H15ClO3
· Molecular weight: 374.82
· Light yellow silky needles from ethanol or acetone
· Melting Point: 138 to 140 °C
· Store at room temperature.
· Soluble in organic solvents (e.g., acetone, ethanol and methanol); very sparingly soluble in water (approximately 100 mcg/mL at 20 °C
· Absorption max. (acetone): 325 nm


Diphacinone (Diphenadione)
:
· Chemical Names: 2-(diphenylacetyl)-1H-indene-1,3(2H)-dione; 2-(diphenylacetyl)-1,3-diketohydrindene; 2-(diphenylacetyl)-1,3-indanedione
· CAS No.: 82-66-6
· Molecular formula: C23H16O3
· Molecular weight: 340.37
· Pale yellow crystals or crystalline powder from ethanol
· Melting Point: 146 to 147 °C
· Store at room temperature.
· Soluble in acetone (approximately 29 mg/mL) and glacial acetic acid; slightly soluble in benzene; practically insoluble in water (approximately 0.3 mcg/mL)
· Decomposes in water by sunlight.
· Partition coefficient: Log P (octanol/water) = 4.8
· Melting Point: 146 to 147 °C
· UV Max (aqueous acid) = 336 nm
· Mass Spectrum: principal ions at m/z 173, 340, 168, 167, 165, 341, 174, 322


General Relevancy:
Numerous oral anticoagulants have been synthesized as derivatives of 4-hydroxycoumarin, a compound that it structurally similar to vitamin K. These oral anticoagulants are vitamin K antagonists since the mechanism of action is based on the ability of the compound to decrease the endogenous formation of reduced vitamin K. It appears that the compounds inhibit vitamin K epoxide reductase.

Coagulation factors II, VII, IX, and X and the anticoagulant proteins C and S are synthesized predominantly in the liver. These proteins must be activated by carboxylation of the amino-terminal glutamic acid residues; full biological activity requires that 9 to 12 of these residues are carboxylated. These γ-carboxyglutamate (Gla) residues confer Ca2+- binding properties to these proteins, an essential step for assembly into an efficient, active catalytic complex. This carboxylation reaction requires carbon dioxide (CO2), molecular oxygen (O2), reduced vitamin K, and a precursor of the target protein (see Figure below from Majerus and Tollefsen, 2001).

anticoag_figure_Vit_K_cycle.jpg
As an example, therapeutic doses of warfarin decrease the total amount of each vitamin K-dependent coagulation factor produced by the liver by 30% to 50%. In addition, the coagulation factors are under-carboxylated, resulting in reduced biological activity (i.e., 10% to 40% of normal). The oral anticoagulants do not affect the activity of pre-formed, fully carboxylated molecules; therefore, the time required for the activity of each coagulation factor depends on its individual rate of clearance. The approximate elimination half-lives (and the common name) of each affected factor is shown below:

Factor VII (Proconvertin) = 6 hours
Factor IX (Christmas Factor) = 24 hours
Factor X (Stuart-Prower Factor) = 36 hours
Factor II (Prothrombin) = 50 hours
Protein C = 8 hours
Protein S = 30 hours

Due to the long elimination half-lives of some of these proteins, the full anticoagulant effect following initial contact with the oral anticoagulants is not observed for several days.

Although many oral anticoagulants have been synthesized, at present only warfarin sodium is used therapeutically. This drug is indicated for (a) the prophylaxis and/or treatment of venous thrombosis and its extension and pulmonary embolism, (b) the prophylaxis and/or treatment of the thromboembolic complications associated with atrial fibrillation and/or cardiac valve replacement, and (c) to reduce the risk of death, recurrent myocardial infarction and thromboembolic events (e.g., stroke) after a myocardial infarction.


The specific antidote for these compounds is vitamin K1 (phytonadione).


Pharmacokinetics (Human)
:
A. Warfarin
Warfarin is readily and almost completely absorbed from the gastrointestinal tract following oral administration; peak concentrations in plasma are observed within 4 hours.

The drug has a very limited distribution (the Vd is approximately 0.14 L/kg). A distribution phase lasting 6 to 12 hours may be observed following IV administration or oral administration of an aqueous solution. Plasma protein binding is approximately 99% at therapeutic doses.

Based on limited published data, warfarin has not been detected in the breast milk of mothers treated with the drug and has not been found in the plasma of nursing infants. However, there are some data that indicate that some breast-fed infants whose mothers were treated with warfarin had prolonged prothrombin times [see Orme et al., 1977]. The consensus is that it is unlikely that maternal warfarin therapy would be hazardous to healthy full-term breast feeding infants.

Warfarin exists as (R)- and (S)-enantiomers. The (R)-enantiomer of warfarin is metabolized predominantly by cytochrome P450 enzymes by reduction to (RS)-2'-hydroxywarfarin; some hydroxylation to 6-hydroxywarfarin also occurs. The (S)-enantiomer of the drug is metabolized by 6- and 7-hydroxylation with smaller amounts of (SS)-2'-hydroxywarfarin formed. The hydroxylated metabolites are inactive, while the reduced 2'-hydroxywarfarin metabolites have some pharmacological activity. In addition to the above, a few minor metabolites of warfarin have been identified, all of which appear to have (at best) minimal anticoagulant activity.

The mean plasma elimination half-life (t1/2) of warfarin is 42 hours (range, 15 to 85 hours). The elimination t1/2 of the (R)-enantiomer (mean about 45 hours; range 37 to 89 hours) appears to be longer than the (S)-enantiomer (mean about 30 hours; range 21 to 43 hours).

Less than 1% of a dose of warfarin is excreted in the urine as unchanged drug. It is reported that between 16 and 43% of a single dose of the drug is excreted in the urine as free or conjugated metabolites over 6 days (predominantly as 7-hydroxywarfarin). To a lesser extent, excreted of metabolites through the bile occurs.


B.
Brodifacoum:
Note: Complete pharmacokinetic data in humans are not available. The information below is the pharmacokinetics that could be found.

Brodifacoum is absorbed from the gastrointestinal tract and through the intact skin.

Peak plasma levels occur within 2 to 3 hours post-ingestion (in horses).

The volume of distribution is approximately 1.0 L/kg.

The metabolism in humans is unknown.

It is known that the compound is retained in organs of animals for long periods of time. For example, in a study that measured the retention of radioactive brodifacoum in livers of rats dosed once with the compound, 34% of the dose was present in the liver after 13 weeks and 11% of the dose was present after 104 week (approaching the normal lifespan of the animal).


The plasma half-life of brodifacoum determined in 3 patients with severe bleeding disorders was found to be approximately 16 to 36 days (see Weitzel et al., 1990). Baselt (2004) references a few studies and, based on those, states that the reported elimination half-life of brodifacoum is between 20 and 62 days.

C. Difenacoum:
Note: Complete pharmacokinetic data in humans are not available. The information below is the pharmacokinetics that could be found.

The metabolism of this compound in humans is unknown.

Although the elimination half-life has not been reported, it is estimated to be between 11 and 42 days.


In one case of poisoning it required 30 days for prothrombin times to return to normal even after continual treatment with vitamin K1 for 45 days (see Barlow et al., 1982).

D. Bromodiolone:
Note: No pharmacokinetic data in humans could be found.

E.
Difethialone:
Note: No pharmacokinetic data in humans could be found.

F.
Chlorophacinone:
Note: Complete pharmacokinetic data in humans are not available. The information below is the pharmacokinetics that could be found.

Chlorophacinone is absorbed from the gastrointestinal tract. Following oral use, it is reported that 90% is eliminated in the feces within 48 hours in the form of metabolites (see Hartley and Kidd, 1983). However, the exact metabolism of this compound in humans has not been thoroughly studied.


Although the elimination half-life has not been reported, in one case of poisoning it required 4 weeks for prothrombin times to return to normal even after adequate therapy (see Dusein et al., 1984). Baselt (2004) references a few studies and, based on those, indicates that the reported elimination half-life of chlorophacinone is between 6 and 23 days.

G. Diphacinone:
Note: Complete pharmacokinetic data in humans are not available. The information below is the pharmacokinetics that could be found.

The compound is absorbed orally. A single oral dose of diphacinone of 4 mg produced a clearly detectable reduction of prothrombin about 14 hours after ingestion and a slightly greater reduction a day later; recovery was observed starting on the third day. A single 2 mg oral dose was somewhat effective in this regard. A single 20 mg oral dose caused distinct hypoprothrombinemia in 14 hours, a marked effect in 48 hours, and this persisted for 6 to 10 days (see Field et al., 1952).


The elimination half-life in humans has been estimated to be between 15 and 20 days.


Proper Specimen Types:

1. Warfarin:
Preferred: Serum or Plasma – For Therapeutic Drug Monitoring or Compliance Monitoring
(Note: The use of serum separator tubes is not recommended.)

Alternate: Whole Blood and Tissues – For Forensic Analysis Only
(
Note: The plasma to whole blood ratio for warfarin is approximately 1.8.)

Urine – not recommended

2. All Other Compounds
:
Preferred: Serum, Plasma or Whole Blood

Alternate: Tissues

Urine – not recommended

Analyte(s) to be Determined:

For Blood, Serum or Plasma:
4-Hydroxycoumarins: Warfarin, Brodifacoum, Difenacoum, Bromodialone, and Difethialone
Indanediones: Chlorophacinone and Diphacinone

Methods of Analysis:
Liquid Chromatography/Mass Spectrometry (LC/MS) or Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
A Reporting Limit of 10 ng/mL for all compounds should be acceptable.

Measurable Range (Upper/Lower Detection Limits):


Critical Concentrations:
1. Warfarin:
A single oral dose of 20 mg of drug resulted in a plasma concentration of 2.7 mcg/mL at 1 hour, declining to 2.1 mcg/mL by 5 hours and 1.2 mcg/mL by 24 hours [see Midha et al., 1974].

Subjects given chronic doses of 10 mg of warfarin per day, the mean steady-state plasma concentration was reported as 2.0 mcg/mL (range, 1.4 to 3.5 mcg/mL). Those given chronic doses of 15 mg of warfarin per day, the mean steady-state plasma concentration was reported as 3.1 mcg/mL (range, 1.7 to 6.8 mcg/mL) [see O’Reilly and Aggeler, 1968].

Steady-state plasma concentrations in 23 controlled patients on long-term warfarin therapy (approx. 2.5 to 15 mg per day) ranged from 0.6 to 3.1 mcg/mL [see Breckenridge and Orme, 1973].

In 6 subjects receiving daily oral doses of 5 to 11 mg of warfarin, steady-state plasma concentrations of 1.2 to 2.6 mcg/mL were attained [see Orme et al., 1977].

Mean steady-state concentrations of warfarin enantiomers (12 hours after the last dose) following a daily dosage regimen of 6.1 ± 2.3 mg of racemic warfarin was:
· 0.9 ± 0.4 mcg/mL of the R-enantiomer
· 0.5 ± 0.2 mcg/mL of the S-enantiomer

[see Chan, et al., 1994].


2. Brodifacoum
:
Hollinger & Pastoor (1993) reported results of comparison of plasma brodifacoum concentrations and prothrombin levels over time in a case of brodifacoum poisoning. Brodifacoum was eliminated according to a two-compartment model, with an initial half-life of 18 hours and a terminal half-life of 24.2 days. On admission, the brodifacoum level was 730 ng/mL.

Weitzel et al. (1990) described three patients with severe bleeding disorders due to deficiency of the vitamin K-dependent blood clotting proteins after ingestion of an anticoagulant. Although the patients denied any ingestion, brodifacoum was detected in their serum at concentrations of 7.6 nmol/litre, 270.7 nmol/litre and 2759 nmol/litre, respectively. The anticoagulant effect was found to persist long after brodifacoum was no longer detectable in the serum.

Baselt (2004) lists 4 studies of adult fatalities with brodifacoum overdoses:
· Postmortem blood concentrations 30 and 117 ng/mL were measured in two individuals who survived for 25 and 30 days, respectively.
· A teenager died 1 day after ingestion of brodifacoum; her postmortem blood concentration was over 3900 ng/mL.


3. Difenacoum
:
Maximum plasma concentrations of 600 ng/mL and 1000 ng/mL were measured in two victims of difenacoum poisoning (see Baselt, 2004).


4. Chlorophacinone
:
Baselt (2004) lists a few studies of fatalities with chlorophacinone overdoses. Admission serum concentrations were reported to be between 6300 and 28000 ng/mL.


5. Bromodialone, Difethialone, and Diphacinone
:
No data have been found.

Potential Interfering Compounds:


Stability Data:

Diphacinone decomposes by sunlight when dissolved in water. Stability in serum, plasma and blood should be checked for stability in ambient light and may need to be “light-protected”. Other compounds appear to be stable.

Interpretative Comment(s):
1. Warfarin:
Serum or Plasma: The usual therapeutic range is 1 to 3 mcg/mL. However, due to individual variability in dosing, therapeutic plasma concentrations up to 7 mcg/mL have been reported. Toxic effects are associated with plasma concentrations greater than 10 mcg/mL.

Blood
: Based on the plasma to whole blood ratio of approximately 1.8, the therapeutic concentration in blood would be about one-half that of plasma.

2. All Other Compounds
:
Blood, Serum or Plasma: This is not a therapeutic compound. Therefore, any concentration measured in blood, serum or plasma is considered to be abnormal.

References:
Barlow, A.M., A.L. Gay and B.K. Park (1982): “Difenacoum (Neosorexa) poisoning,” Br. Med. J. 285: 541.

Breckenridge, A., and M.L. Orme (1973): “Measurement of plasma warfarin concentrations in clinical practice,” In: Biological Effects of Drugs in Relation to Their Plasma Concentrations, D.S. Davies and B.N.C. Pritchard (eds.), University Park Press, Baltimore, pp. 145-154.

Chan, E., A.J. McLaschlan, M. Pegg, A.D. MacKay, R.B. Cole and M. Rowland (1994): “Disposition of warfarin enantiomers and metabolites in patients during multiple dosing with racemic warfarin,” Br. J. Clin. Pharmacol. 37: 563-569.


Dusein, P., G. Manigaud and J. Taillandier (1984): “Sevcere and prolonged hypoprothrombinemia following chlorphacinone poisoning,” Presse Med. 13: 1845 (in French).

Field, J.B., M.S. Goldfarb, A.G. Ware and G.C. Griffith (1952): “Effect in man of a new indanedione anticoagulant,” Proc. Soc. Exp. Biol. Med. 81: 678-681.

Hollinger, B.R., and T.P. Pastoor (1993): “Case management and plasma half-life in a case of brodifacoum poisoning,” Arch. Intern. Med. 153: 1925-1928.


Midha, K.K., I.J. McGilveray and J.K. Cooper (1974): “GLC determination of plasma levels of warfarin,” J. Pharm. Sci. 63: 1725-1729.

O’Reilly, R.A., and P.M. Aggeler (1968): “Studies on coumarin anticoagulant drugs,” Circulation 38: 169-177.

Orme, M.L., P.J. Lewis, M. de Swiet, M.J. Serlin, J.D. Baty and A.M. Breckenridge (1977): “May mothers given warfarin breast-feed their infants?,” Br. Med. J. 1: 1564-1565.

Hartley, D., and H. Kidd (1983): The Agrochemicals Handbook, The Royal Society of Chemistry, Nottingham, England.

Majerus, P.W., and D.M. Tollefsen (2001): “Anticoagulant, Thrombolytic, and Antiplatelet Drugs,” In Goodman & Gilman’s The Pharmacological Basis of Therapeutics, Tenth Edition, Hardman, J.G., and L.E. Limbird (eds), McGraw-Hill, New York, pp. 1526-1531.

Pelfrene, A.F. (1991): “Synthetic Organic Rodenticides,” In Handbook of Pesticide Toxicology, Volume 3 – Classes of Pesticides, W.J. Hayes, Jr., and E.R. Laws, Jr. (eds), Academic Press, San Diego, pp. 1290-1302.

Thummel, K.E., and D.D. Shen (2001): “Design and Optimization of Dosage Regimens: Pharmacokinetic Data,” In Goodman & Gilman’s The Pharmacological Basis of Therapeutics, Tenth Edition, Hardman, J.G., and L.E. Limbird (eds), McGraw-Hill, New York, p. 2021.


Weitzel, J.N., J.A. Sadowski, B.C. Furie, R. Moroose, H. Kim, M.E. Mount, M.J. Murphy and B. Furie (1990): “Surreptitious ingestion of a long-acting vitamin K antagonist/rodenticide, brodifacoum: Clinical and metabolic studies of three cases,” Blood 76: 2555-2559.


Baselt, R.C. (2004): Disposition of Toxic Drugs and Chemicals in Man, 7th Edition, Biomedical Publications, Foster City, pp. 123-124, 207-208, 336-337, 1194-1196.


Clarke’s Analysis of Drugs and Poisons, 3rd Edition
(2004), Moffat, A.C., M.D. Osselton and B. Widdop (eds.), Pharmaceutical Press, London, pp. 935, 1703-1704.

The Merck Index, 14th Edition
(2006), O’Neil, M.A. (ed.), Merck & Co., Whitehouse Station, pp. 226, 356, 531, 532, 560, 1729.

Drug Facts and Comparisons
(2006), Wolters Kluwer Health, Inc., St. Louis, pp. 177-181 (revised April 2003).


Inchem Data on Environmental Health Criteria 175 - Anticoagulant Rodenticides.
www.inchem.org/documents/ehc/ehc/ehc175.htm (reviewed December 5, 2006).


General Questions:
1. What is the application of the test?
To quantify the concentrations of 7 oral anticoagulant rodenticides available in the U.S. in blood, serum, plasma or tissues from individuals exposed (i.e., poisoned) with one of these drugs.

2. Who would use this application and why?
Medical Examiners / Coroners for Forensics
Clinicians for Overdoses


The analyses would be useful for monitoring (confirming) poisoning cases and to assess potential toxicity.


3. Is testing currently available / new to the industry by some other means?
Yes. The quantitation of some of these drugs is presently being performed by high performance liquid chromatography (HPLC).

4. What are the features / benefits of this test to the user?
The major benefit is the expansion of NMS Labs capabilities to identify an quantify more compounds in this class of agents.

The use of liquid chromatography/mass spectrometry (LC/MS) to identify and quantify these compounds will improve the sensitivity and specificity of the current NMS method.


5. What is the scientific significance of this test?

The assay is a quantitative measurement of a variety of oral anticoagulant rodenticies in blood, serum, plasma or tissues and the analysis has no known interferences.