Agricultural Uses of Antibiotics - American Chemical Society

15

Pharmacokinetics and Residues of Sulfadimidine 4

and Its N -Acetyl and Hydroxy Metabolites in Food-Producing Animals

1

2

3

4

J. F. M.Nouws ,T. B.Vree ,R.Aerts ,and J. Grondel

Downloaded by CORNELL UNIV on August 22, 2016 | http://pubs.acs.org Publication Date: September 18, 1986 | doi: 10.1021/bk-1986-0320.ch015

1

R.V.V.-District 6, P.O.Box 40010, Nijmegen, the Netherlands Department of Clinical Pharmacy, Sint Radboud Hospital, Nijmegen, the Netherlands RIKILT, Wageningen, the Netherlands ZODIAC, University of Wageningen, the Netherlands

2

3

4

Employing s p e c i f i c HPLC methods, the pharmacokinetics of sulfadimidine (SDM) and its metabolites N -acetyl (N -SDM), 6-hydroxymethyl (SCH OH), 5-hydroxy (SOH), and g l u c u r o n i d e (SOH-gluc.) were s t u d i e d i n v a r i o u s s p e c i e s . In general the SDM e l i m i n a t i o n half-lives depended on the metabolic rate and extent of metabolism as well as the renal excretion rate of the metab o l i t e s . N -SDM, SCH OH and SOH metabolites exhibited higher renal clearance values than SDM. Hydroxylation of SDM dominates in horses, c a l v e s , cows, and l a y i n g hens. The main metabolite i n horses was SOH; i n ruminants, SCH OH. In c a l v e s and cows at high dose l e v e l s (100 SDM mg/kg), a biphasic elimination SDM plasma concentration-time curve was observed with a steady state plasma SCH OH c o n c e n t r a t i o n r e s u l t i n g from the c a p a c i t y l i m i t e d hydroxylation of SDM into the l a t t e r . The drug concentrations i n the milk reflected those i n plasma. In calves and pigs, the SDM concentration i n plasma exceeded that in muscle, kidney or liver t i s s u e . The N -SDM t i s s u e c o n c e n t r a t i o n was lower than that of SDM; in the c a l v e s kidney, the SCH OH c o n c e n t r a t i o n exceeded that of SDM. In pigs, the acetylation pathway was predominant; no hydroxy metabolites could be detected i n plasma and edible tissues. Eggs layed within 7 days after SDM therapy (100 mg SDM/kg/day) has been t e r m i n a t e d show d e t e c t a b l e q u a n t i t i e s of the parent drug and its metabolites. 4

4

2

4

2

2

2

4

2

There are three main v a r i a b l e s governing the p h a r m a c o k i n e t i c s of sulfonamides i n animals,namely : 1) the molecular structure of the sulfonamide, 2) the mechanism and route of metabolism and 3) the r e n a l e x c r e t i o n . By s e l e c t i n g one sulfonamide, e.g. s u l f a d i m i d i n e (SDM), for a comparative study, one i s able to study species d i f f e 0097-6156/86/0320-0168S06.00/ 0 © 1986 American Chemical Society

Moats; Agricultural Uses of Antibiotics ACS Symposium Series; American Chemical Society: Washington, DC, 1986.


15.

Pharmacokinetics and Residues of Sulfadimidine

NOUWSETAL.

169

rences i n metabolism , t i s s u e d i s p o s i t i o n and r e n a l c l e a r a n c e s . Numerous r e p o r t s d i s c u s s i n g s p e c i e s d i f f e r e n c e s i n e l i m i n a t i o n h a l f - l i v e s for SDM as well as other sulfonamides, have been reviewed s u l f a d i m i d i n e i n e.g. horses, p i g s , ruminants, f o w l s , f i s h are obtained by the Bratton & Marshall method, which cannot d i s t i n g u i s h SDM from i t s hydroxy metabolites. Recently the hydroxy metabolites of various sulfonamides could be isolated and p u r i f i e d , so that s p e c i f i c HPLC techniques could be developed (22,23). As shown i n Figure 1, sulfadimidine can be metabolized by hydroxylation at the 5 and 6 p o s i t i o n of the pyrimidine r i n g and by the a c e t y l a t i o n - d e a c e t y l a t i o n pathway (21). A f t e r hydroxylation, the metabolites may become g l u c u r o n i d a t e d and a l s o acetylated (Figure 2). The hydroxy metabolites are m i c r o b i o l o g i c a l l y active and they can be potentiated by trimethoprim (13). Because of i t s widespread therapeutic use and because the question of residues i n food producing animals, SDM was selected for a study between species to compare i t s metabolism , the pharmacokinetics of the parent drug as w e l l as i t s metabolites. Residue depletion studies were performed i n edible tissues of calves, pigs and in the eggs of laying-hens.

MATERIAL AND METHODS Drugs Sodium sulfadimidine (33.3%) was obtained from A.U.V. (Cuyk,The Netherlands). N^-acetylsulfadimidine (N^-SDM), 6 - h y d r o x y m e t h y l - s u l f a d i m i d i n e (SCH OH) and 5-hydroxysulfadimidine (SOH) were synthesized and isolated according Vree et a l . (22,23). 2

Experiments Animals were obtained from Mr. van Raay i n G a s s e l , the C e n t r a l Animal Laboratory at the University of Nijmegen, Large Animal C l i nics at the University of Utrecht, and from Zodiac at the A g r i c u l t u r a l University of Wageningen, the Netherlands. SDM was a d m i n i s t e r e d e i t h e r i n t r a v e n o u s l y , i n t r a m u s c u l a r l y , o r a l l y , or i n t r a p e r i t o n e a l l y to horses, calves, cows, pigs, l a y i n g hens and carp. Heparinized blood samples were taken at regular time i n t e r v a l s , centrifuged and plasma was deep frozen at -20 C pending HPLC a n a l y s i s . Urine was c o l l e c t e d by e i t h e r spontaneous v o i d i n g , catheterisation, or with special c o l l e c t i o n urine and feces f a c i l i t i e s for the horses, ruminants, and pigs. When the pigs and calves were s l a u g h t e r e d , specimens of kidney, l i v e r , muscle, plasma, and u r i n e were sampled and prepared as d e s c r i b e d (16). The eggs of laying hens were collected during SDM administration and for the 14 days post administration. For the carp, water samples were taken at 4 to 12 h i n t e r v a l s , after which the water was changed. HPLC Analysis D e g l u c u r o n i d a t i o n , sample p r e p a r a t i o n and HPLC analysis were performed as described elsewhere (14,15,16). SDM, i t s N^-SDM, and two hydroxymetabolites were determined s i multaneously i n the several test specimen.


AGRICULTURAL USES OF ANTIBIOTICS


170

F i g u r e 1. M o l e c u l a r s t r u c t u r e s of s u l f a d i m i d i n e (SDM), i t s 5hydroxy-4,6-dimethyl-pyrimidine (SOH), i t s 6-hydroxymethyl-4m e t h y l - p y r i m i d i n e (SCH 0H) and i t s N / - a c e t y l m e t a b o l i t e ( N SDM)• * * 9

A

Z

Glucuronldation

SCOOH^

1?

N^-SCOOH ?

2? OXIDATION?

Other pathways -desamination -glycoside ? -ornithine ? -glycine ? -sulfation ?

-SCHoOH.

"\

1

NrSCH20H—i

2?

6-methyl hydroxylation

SDM:

Nil -SDM

5-hydroxylation

-Hi|-S0H

SOH 1 = Acetylation 2 = Deacetylation

2?

GlucuronidationFigure 2. Metabolic pathways of sulfadimidine.


15.

NOUWSETAL.


171

RESULTS


Table I summarizes the percentages of sulfadimidine and i t s metabol i t e s i n the plasma of the d i f f e r e n t s p e c i e s ; Table I I shows the tissue to plasma drug concentration ratios for SDM and i t s metabol i t e s , while Table III presents the urinary recovery data (for poultry urinary plus faecal recovery). The metabolic pathways observed i n various species are summarized i n a scheme (Figure 2). Selected data obtained are i l l u s t r a t e d i n Figures 3 - 9 . Horses In the horse, hydroxylation i s more important than acetylation as a metabolic pathway, with hydroxylation at the 5 p o s i t i o n being dominant over h y d r o x y l a t i o n of the 6-methyl group. Low percentages of m e t a b o l i t e s are present i n plasma, f o r N^-SDM, 0.6 to 0.9 %; f o r SCH 0H, 0.38 to 0.71 %; and f o r SOH, 0.38 to 6.7 %. The plasma concentration-time curves of the metabolites run p a r a l l e l to that of SDM. The elimination h a l f - l i f e of sulfadimidine varies between 5 and 14 h. The main metabolite i n urine, accounting for 50 % of the drugs present (Table III), i s the SOH and i t s glucuronide. 2

Cows and calves SDM i s e x t e n s i v e l y hydroxylated i n t o hydroxy d e r i v a t i v e s and to a lesser extent acetylated into N^-SDM. Hydroxylation of the 6-methyl group to form 6-hydroxymethylsulfadimidine dominates (1.5 times) h y d r o x y l a t i o n at the 5 p o s i t i o n (Table I I I ) . At h i g h dosage levels! (100 -200 mg/kg), a biphasic e l i m i n a t i o n SDM plasma concentrationtime curve was observed with a steady state plasma concentration of SCH 0H (6-15 ^/lg/ml) during the period i n which the SDM plasma concentration exceeded 20 jug/ml. A c a p a c i t y l i m i t e d h y d r o x y l a t i o n of SDM into SCH^OH was noticed i n ruminant calves and cows at a dosage l e v e l of 100-200 mg/kg (15). An unknown m e t a b o l i t e (X) and i t s glucuronide was detected either i n the plasma (Figure 3) or urine of cows, goats, and horses (Table I and III). The unknown metabolite (X) may be the f u r t h e r o x i d a t i o n product of the 6-hydroxymethyl metabolite. In which case i t was tentatively assumed to be 6-carboxysulfadimidine and i t s glucuronide. (In c a l c u l a t i n g the concentration of the unknown metabolite, which eluted from the HPLC column just before the 5-hydroxy metabolite (SOH), the molar extinction of SOH was used). This unknown metabolite did not penetrate the udder (Figure 4) presumably because of i t s polar nature. The N^-SDM plasma concentrations run p a r a l l e l to SDM beyond 4 h after i n j e c t i o n at a l l dosages i n a l l animals. In m i l k , the c o n c e n t r a t i o n of SDM and i t s m e t a b o l i t e s was a r e f l e c t i o n of those i n plasma (14; Figure 4). The d i s p o s i t i o n of SDM i n plasma , edible tissues, b i l e and urine of calves are i l l u s t r a t e d i n Figure 5. As shown, the SDM concentration i n plasma was higher than that i n the edible tissues. The l a t t e r i s also confirmed by the tissue to plasma concentration ratios of SDM and i t s metabolites which were lower than 1, except for the metabolite ratios i n kidney tissue (Table II). The SCH 0H concentration i n the kidney exceeded those of SDM (Figure 6). The N^-SDM m e t a b o l i t e c o n c e n t r a t i o n s i n muscle, kidney and l i v e r were always below those of SDM (Table II; 2

2



20-200 95.0

87.8 96.8

100

20

100

Goat

Horse

Pigs

Poultry

Flsh(carp) 560

+

0.4

2.8

t

1.2

4.5

7.5

0.05

—

—

10.0

3.8

0.5

0.7

a

5.4

7.2

m

3.9 1.0

22.4 9.7

2.1 2.3 1.5

1.4 0.7

30.9 8.6

5.7 11.0

— —

— —

32.7 67.3

2

X SCH OH X SOH

4

X N -SDM

—

—

—

—

8.5

3.4 2.2

— —

— —

XX ^ ^ j

v

t a b o l i t e 8

(a) S = slow acetylator phenotype; F ™ fast acetylator phenotype. 1) Percentage of ADC vs total ADC (= ADC «e )•

90.0

77.6

70.5 85.4

10 100

Cow

62.6 79.7

57.6 23.5

12 12

10 100

a

X SDM

Dose

Calf

Man ( S ) (F)

SPECIES

16

17

15 15

15 15

Reference

Table I MEAN PERCENTAGES OF SULFADIMIDINE AND ITS METABOLITES IN PLASMA OF DIFFERENT SPECIES.


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NOUWS ET AL.

173


Table II CONCENTRATION RATIO'S OF SULFADIMIDINE AND ITS METABOLITES BETWEEN TISSUE SPECIMEN AND PLASMA.


Drug concentration in specimen vs. plasma Calves

SIM

SCH 0H 2

SOH

N-SDM 4

3

Mean and standard deviation .

Kidney vs plasma

0.34+0.18 1.89+1.18 4.76+1.14 2.50+0.54 (n-11) (n-4) (n-3) (n-12)

Muscle ) vs plasma homogenate)

0.38+0.18 0.36+0.10 0.18+0.02 0.20+0.04 (n-4) (n-4) (n-10) (n-3)

Muscle drip vs plasma

0.39+0.20 0.32+0.02 0.23+0.13 0.38+0.06 (n-4) (n-4) (n-10) (n-5)

Liver vs plasma

0.24+0.18 0.27+0.13 0.31+0.20 0.43+0.18 (n-3) (n-7) (n-3) (n-3)

Pigs Kidney vs plasma

0.29+0.06 (n-10)

—

—

1.26+0.67 (n-9)

Muscle homogenate vs plasma

0.19+0.08 (n-10)

—

—

0.38+0.23 (n-10)

Muscle drip vs plasma

0.42+0.15 (n-11)

—

—

0.45+0.23 (n-10)

Liver vs plasma

0.15+0.12 (n-8)

—

—

0.33+0.30 (n-4)

a - Number of samples i n parentheses. — = absent



100

200

560

Goat

Horse

Fish (carp) Man ( S ) (F)

Poultry

20

Pigs

— a) b) c) d)

100

12 12

10 100

Cow

d

10 100

Calf

2 e

e

84 88

a

a

0-60 0-60

0-48

0-27

42

88 87

64.4

25

98

13.9

12.9 3.6

62.2

12.1

62.5 74.1

1.8

1.4 10.1 (40.5 )(5.6) C

41.0

13.4 4.5

7.2 9

9.7 26

15.1

13 34

7 22

4

10.2

6.3 7.0

0.23

0.25 (1.0)

28.2

18.7

50.5 26

50 26

b

2

—

—

4.7

5.8

3.5 0.75

0.18

12.7 (51)

30.9

— — —

—

—

—

2.8 1.56

—

0.4 (1.4)

18.2

4.8 2.3

— 0.2

18.0 8

1.4

— —

— —

14 6

= not detected Diphasic elimination-time curve (both elimination half-lives given). present as an acetylated derivative. relative percentage of the total recovered drug i n 27 h i n parenthesis S = slow acetylator phenotype; F = fast acetylator phenotype

101-3.5 0-60

7.7 1.6+5

17.5

9.5

2.7-3.8 0-20

0-140 77.8

0-72 0-120

m

9-14

a

i

86 72

T

3.5 0-72 12+6.5 0-72

a

3.5 15+5

1

PLASMA ELIMINATION HALF-LIFE, AND URINARY RECOVERY OF SULFADIMIDINE AND ITS METABOLITES EXPRESSED AS PERCENTAGES OF THE DOSE ADMINISTERED (mean values) IN DIFFERENT SPECIES. SPECIES Dose T y l URINARY RECOVERY EXPRESSED AS PERCENTAGE OF THE DOSE period mg/kg hours in Total ZSDM ZN -SDM %SCH OH ZSOH ZX ZX,glue hours recovery (+gluc)

Table III


00

H o

o

55

> Z H

O

r c m

>

c

^

o c

15.

NOUWS ET AL.


175


Concentration, /ug/ml plasma

F i g u r e 3. Plasma c o n c e n t r a t i o n - t i m e curves of s u l f a d i m i d i n e (SDM), and i t s 6-methylhydroxy (CH-OH), 5-hydroxy (SOH) and i t s g l u c u r o n i d e ( S O H i ) > N ^ - a c e t y l CN^) and unknown (X) metabol i t e s i n a cow after an intravenous dose of 200 mg/kg s u l f a d i m i dine. g

uc

Concentration, AJg/ml m i l k

Figure 4. Disposition of sulfadimidine (SDM), i t s 6-methylhydroxy (CH^OH), 5-hydroxy (SOH) and N ~ a c e t y l ( N ) m e t a b o l i t e s i n milk or a dairy cow following intravenous administration of 200 mg SDM/kg. 4

4


176



Concentration, /ug/ml o r g t i s s u e

0

1

2

3

D a y s

a f t e r

administration

F i g u r e 5. D i s p o s i t i o n of s u l f a d i m i d i n e i n u r i n e , b i l e , plasma and tissues of calves following intravenous administration of 65 mg/kg intravenously.



NOUWS ET AL.


111

F i g u r e 6. D i s p o s i t i o n of sulfadimidine(SDM), 6-methylhydroxy (CHoOH), and N^-acetylsulfadimidine ( N ) i n the kidney of calves following intravenous administration of 65 mg SDM/kg. 4



178


T-,6.4 H

0.1SULFADIMIDINE ORALLY Multiple doslngdOO mg/kg) (1)

Z

0.01.

1

I

L oti

s

50 100(4) 15

Agricultural Uses of Antibiotics - American Chemical Society

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