Antibiotic Antibiotic accumulation and efflux accumulation and - - PowerPoint PPT Presentation

Antibiotic Antibiotic accumulation and efflux accumulation and efflux in eukaryotic cells: in eukaryotic cells: a journey at the frontier a journey at the frontier

• f pharmacokinetics
• f pharmacokinetics

and and pharmacodynamics

“corpora non agunt nisi fixata” Ehrlich’s “magic bullet” theory

pharmacodynamics

Unité de Pharmacologie cellulaire et moléculaire

• F. Van Bambeke

Magic bullets need to reach their target

Magic bullets need to reach their target

glycopeptides β-lactams quinolones macrolides aminoglycosides

for appropriate time and in sufficient concentration …

Birth of antibiotic “PK-PD”

Concentration versus time in tissues and

• ther body fluids

Pharmacologic

• r toxicologic

effect Concentration versus time in serum Dosage regimen Concentration versus time at site

• f infection

Antimicrobial effect versus time

absorption distribution elimination

PHARMACOKINETICS PHARMACODYNAMICS Craig (1998) CID 26:1-10

ISAP classical view of PK/PD

but classical PD predicts concentration-effects for all drugs ….

but classical PD predicts concentration-effects for all drugs ….

ampicillin gentamicin

• S. aureus; 24 h

Barcia-Macay et al, submitted; Lemaire et al (2005) JAC in press

Can we conciliate both theories ?

Cmin Cmax conc.-dependent Cmin Cmax

PD profile in the clinics

time -dependent ampicillin gentamicin

• S. aureus; 24 h

Barcia-Macay et al, submitted; Lemaire et al (2005) JAC in press

Target accessibility becomes critical for intracellular activity

Main routes of drug entry in cells

passive diffusion channel transporter transporter endocytosis active

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic

• r toxicologic

effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial effect versus time

penetration distribution efflux

PHARMACOKINETICS PHARMACODYNAMICS

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic

• r toxicologic

effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial effect versus time

penetration penetration distribution distribution efflux

glycopeptides

PHARMACOKINETICS PHARMACODYNAMICS

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic

• r toxicologic

effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial Antimicrobial effect versus effect versus time time

penetration penetration distribution distribution efflux

glycopeptides

PHARMACOKINETICS PHARMACODYNAMICS

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic Pharmacologic

• r
• r toxicologic

toxicologic effect effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial effect versus time

penetration penetration distribution distribution efflux

glycopeptides

PHARMACOKINETICS PHARMACODYNAMICS

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic

• r toxicologic

effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial effect versus time

penetration distribution efflux efflux

macrolides quinolones

PHARMACOKINETICS PHARMACODYNAMICS

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic

• r toxicologic

effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial Antimicrobial effect versus effect versus time time

penetration distribution efflux efflux

macrolides quinolones

PHARMACOKINETICS PHARMACODYNAMICS

Accumulation of magic bullets in eukaryotic cells

glycopeptides

Vancomycin, the parent compound

O O N H H N N H H N NH O HO Cl O O O O HO OH O NHC H3 HN O HOOC OH CONH2 Cl O OH HO HO O O H3C CH3 H2N HO OH

O O N H H N N H H N NH O O Cl O O O O HO OH O NHC H3 HN O HOOC OH CONH2 Cl O OH HO HO O O H3C CH3 HN OH Cl O H2N CH3 HO H3C OH

The glycopeptide oritavancin, a voluminous, amphiphilic molecule

From vancomycin to oritavancin

O O N H H N N H H N NH O HO Cl O O O O HO OH O NHC H3 HN O HOOC OH CONH2 Cl O OH HO HO O O H3C CH3 H2N OH

epi-vancosamine

OH

From vancomycin to oritavancin

O O N H H N N H H N NH O O Cl O O O O HO OH O NHC H3 HN O HOOC OH CONH2 Cl O OH HO HO O O H3C CH3 H2N OH O H2N CH3 HO H3C OH

4-epi-vancosamine self-association capacity

LY264626

From vancomycin to oritavancin

O O N H H N N H H N NH O O Cl O O O O HO OH O NHC H3 HN HOOC OH CONH2 Cl O OH HO HO O O H3C CH3 HN OH Cl

lipophilic side chain activity including against resistant enterococci

OH O O O H2N CH3 HO H3C

Cooper et al (1996) J Antibiot 49: 575-81

Oritavancin, a cationic amphiphile

O O N H H N N H H N NH O O Cl O O O O HO OH O NHC H3 HN O HOOC OH CONH2 Cl O OH HO HO O O H3C CH3 HN OH Cl O H2N CH3 HO H3C OH

lipophilic side chain additional protonable amine

Oritavancin, a cationic amphiphile

New chemical entity

New pharmacodynamic properties ? New pharmacokinetic profile ? But also ... new potential side effects ?

Spectrum of activity

bacteria resistance vancomycin

• ritavancin

enterococci susc. VanA VanB 1-2 >128 8-128 0.06-0.25 1-4 0.125

• S. aureus

Methi-S Methi-R GISA GRSA 1-2 1-4 8 > 128 1 1-2 1-8 0.5

• highly active on susc. enterococci
• active on VAN-resistant strains

Van Bambeke et al. (2004) Drugs 64:913-36

Pharmacodynamic profile

VANCOMYCIN: modestly bactericidal

• slow
• no or little conc. effect
• ritavancin

6 12 18 24

time (h)

ORITAVANCIN: highly bactericidal:

• rapid
• conc. dependent

vancomycin

6 12 18 24

• 6
• 4
• 2

2 4

time (h) ∆log CFU from time 0

1 X MIC 10 X MIC control 40 X MIC

• S. aureus

Barcia-Macay et al. submitted

Pharmacokinetic properties

parameter Vancomycin (15 mg/kg) Oritavancin (3 mg/kg) peak (mg/L) trough (mg/L) protein binding terminal t½ (h) 20-50 31 5-12 (24 h) 1.7 (24 h) 10-55 % 90 % 4-8 360

• daily administration
• retention in the organism ?

Van Bambeke et al. (2004) Drugs 64:913-36

Aim of the study

• activity against (multi-resistant) Gram-positive (S. aureus)
• rapid bactericidal activity
• retention in the organism

any place for intracellular infections? accumulation and subcellular distribution in eukaryotic cells cellular pharmacokinetics: activity against intracellular S. aureus cellular pharmacodynamics: morphological and biochemical alterations cellular toxicity:

Aim of the study

• activity against (multi-resistant) Gram-positive (S. aureus)
• rapid bactericidal activity
• retention in the organism

any place for intracellular infections? accumulation and accumulation and subcellular subcellular distribution distribution in in eukaryotic cells eukaryotic cells cellular pharmacokinetics: cellular pharmacokinetics: activity against intracellular bacteria cellular pharmacodynamics: morphological and biochemical alterations cellular toxicity:

Kinetics of accumulation-efflux

Oritavancin accumulation and release are slow

J774 macrophages; extracell. conc. 25 mg/L; 24 h Van Bambeke et al. (2004) AAC 48:2853-60

Comparison with other antibiotics

Oritavancin reaches exceptional cellular accumulation levels

vancomycin azithromycin 100 200 300 400

accumulation ratio

• ritavancin

J774 macrophages; extracell. conc. 25 mg/L; 24 h Van Bambeke et al. (2004) AAC 48:2853-60

Subcellular localization

lysosomes mitochondria membrane

N-acetyl-β-glucosaminidase cytochrome c-oxydase inosine diphosphatase Van Bambeke et al. (2004) AAC 48:2853-60

Subcellular localization

Oritavancin is a lysosomotropic antibiotic lysosomes mitochondria membrane

N-acetyl-β-glucosaminidase cytochrome c-oxydase inosine diphosphatase Van Bambeke et al. (2004) AAC 48:2853-60

Mechanism of cellular accumulation

chloroquine azithromycin + ++ HRP latex beads

Mechanism of cellular accumulation

Oritavancin kinetics of accumulation are very similar to those of tracers of (adsorptive) endocytosis accumulation ratio

kinetics of accumulation

Van Bambeke et al. (2004) AAC 48:2853-60

Aim of the study

• activity against multi-resistant Gram-positive (S. aureus)
• rapid bactericidal activity
• retention in the organism

any place for intracellular infections? accumulation and distribution in eukaryotic cells cellular pharmacokinetics: activity against activity against intracellular bacteria intracellular bacteria cellular pharmacodynamics: cellular pharmacodynamics: morphological and biochemical alterations cellular toxicity:

Intracellular activity on S. aureus

control

• ritavancin

Oritavancin can destroy intracellular bacteria

THP-1 macrophages; extracell. conc. 25 mg/L; 24 h Barcia-Macay et al. submitted

Time-effect for intracellular activity

5 10 15 20 25 101 103

time (h) CFU / mg prot

105 107

vancomycin

• ritavancin

Oritavancin shows time- and concentration-dependent intracellular bactericidal effects

2.5 µg/ml 25 µg/ml 0.25 µg/ml 10 µg/ml 50 µg/ml control

J774 macrophages Seral et al (2003) AAC 47: 2283-92

Dose-effect for extracell. vs intracell. activity

intracellular activity < extracellular activity extra intra static conc. 0.3 X MIC 4.8 X MIC max. effect

• 5.55 log
• 3.15 log

THP-1 macrophages; 24 h Barcia-Macay et al. submitted

Dose-effect

intracellular activity < extracellular activity, but bactericidal effects reached at clinically-relevant concentrations

Cmin Cmax

Barcia-Macay et al. submitted

Comparison with other antibiotics

MIC 10 X MIC Cmax

• ritavancin is one of the most active drugs against intracellular S. aureus

THP-1 macrophages; 24 h Barcia-Macay et al. submitted

Aim of the study

• activity against multi-resistant Gram-positive (S. aureus)
• rapid bactericidal activity
• retention in the organism

any place for intracellular infections? accumulation and subcellular distribution in eukaryotic cells cellular pharmacokinetics: activity against intracellular bacteria cellular pharmacodynamics: morphological and biochemical alterations cellular toxicity:

Morphological studies

macrophages fibroblasts

polar lipids

Rat embryo fibroblasts; 25 mg/L; 3 days J774 macrophages, 25 mg/L; 1 day Van Bambeke et al. (2005) AAC – in press

Biochemical studies : time-effects

accumulation of phospholipids and cholesterol develops in parallel with oritavancin cellular concentration

drug-free medium drug-free medium drug-free medium

Rat embryo fibroblasts; 25 mg/L Van Bambeke et al. (2005) AAC – in press

Biochemical studies : dose-effects

Rat embryo fibroblasts, 3 days J774 macrophages, 1 day Van Bambeke et al. (2005) AAC – in press

Model of the interaction of oritavancin with eukaryotic cells

• S. aureus

polar lipids

• ritavancin

undefined material

Can we dissociate activity from toxicity ?

cellular alterations co-exist with destroyed bacteria ….

THP-1 macrophages; 25 mg/L; 24 h

Can we dissociate activity from toxicity ?

comparison with two other lysosomotropic cationic antibiotics

O O O CH H2N NH2 OH HN H3C CH3 OH HO H2N O HN R1 R2

gentamicin

• polycationic, hydrophilic
• endocytosis
• phospholipidosis

O CH3 OH OH OH CH3 CH2CH3 O O CH3 CH3 CH3 O O O OH N(CH3)2 CH3 OH N CH3 CH3 CH3 OCH3 CH3

azithromycin

• dicationic
• diffusion/segregation
• accumulation of phospholipids

and cholesterol

Lysosomotropic antibiotics and activity on S. aureus

GEN and ORI are both conc.-dependent intracellularly

J774 macrophages

Lysosomotropic antibiotics and activity on S. aureus

GEN and ORI are both conc.-dependent intracellularly

J774 macrophages

Lysosomotropic antibiotics and activity on S. aureus

But GEN activity limited at clinically-relevant conditions

J774 macrophages

Lysosomotropic antibiotics and phospholipidosis

Phospholipidosis developing on a conc.-dependent manner

Rat embryo fibroblasts

Lysosomotropic antibiotics and phospholipidosis

Toxic potential variable at clinically-relevant conditions

Rat embryo fibroblasts

Lysosomotropic antibiotics and phospholipidosis

Toxic potential variable at clinically-relevant conditions

Rat embryo fibroblasts

Lysosomotropic antibiotics and phospholipidosis

Toxic potential variable at clinically-relevant conditions

Rat embryo fibroblasts

Can we dissociate activity from toxicity ?

both processes are dependent on cellular concentration …

• 3
• 2
• 1

100 120 140 160 180

intracellular activity cellular toxicity

GEN AZM ORI

… and develop in parallel

Conclusion

amphiphilic glycopeptides, a new type of « magic bullets»

pharmacokinetics: lysosomotropic accumulation bactericidal, conc-dep. activity pharmacodynamics:

• conc. and time-dependent

cellular toxicity cellular toxicity:

Morphological studies

Rat embryo fibroblasts; 25 mg/L; 3 days J774 macrophages, 25 mg/L; 1 day

macrophages fibroblasts polar lipids

Van Bambeke et al. (2005) AAC – in press

• conc. and time-dependent

bactericidal activity towards extra AND intra

• S. aureus

cellular pharmacodynamics:

Dose-effect

intracellular activity < extracellular activity, but bactericidal effects reached at clinically-relevant concentrations

Barcia-Macay et al. submitted Cmin Cmax

Questions for future work

• S. aureus

polar lipids

• ritavancin

undefined material

?

binding site ? reasons for reduction in activity intracellularly in vivo ? mechanism

• f accumulation

?

Take home message

cellular accumulation, the best and the worse of properties… drug development activity toxicity

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic

• r toxicologic

effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial effect versus time

penetration distribution efflux efflux

macrolides quinolones

PHARMACOKINETICS PHARMACODYNAMICS

Intracellular “PK-PD”

Concentration versus time in non-infected cells Pharmacologic

• r toxicologic

effect Concentration versus time in cells Dosage regimen Concentration versus time at intracellular site of infection Antimicrobial Antimicrobial effect versus effect versus time time

penetration distribution efflux efflux

macrolides quinolones

PHARMACOKINETICS PHARMACODYNAMICS

Efflux of magic bullets from eukaryotic cells

macrolides quinolones

Why efflux transporters ?

polar drug lipophilic drug physico-chemical properties are inadequate for reaching an intracellular target !

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70

Why efflux transporters ?

amphipathic drug most drugs are amphipathic by design, to be able to cross membrane barriers !

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70

Why efflux transporters ?

But a diffusible compound may have

potentially harmful effects !

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70

Why efflux transporters ?

Extrusion by efflux pumps

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70

Why efflux transporters ?

Extrusion by efflux pumps general mean of protection against cell invasion by diffusible molecules

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70

Mechanisms of active efflux

ATP ADP+Pi

membrane insertion / release vacuum cleaner flippase flip-flop

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70

Antibiotics as substrates of efflux pumps

Antibiotic bacteria fungi superior class Gram (+) Gram(-) eucaryotes β-lactams fusidic acid macrolides streptogramins tetracyclines aminoglycosides chloramphenicol rifamycins sulfamides trimethoprim fluoroquinolones

Van Bambeke et al. (2000) Biochem. Pharmacol. 60:457-70

Antibiotics as substrates of efflux pumps

O H3C OH OH OH CH3 H3CH2C O O CH3 CH3 H3C O O O HO (H3C)2N CH3 OH N CH3 CH3 H3C H3C H3CO

azithromycin ciprofloxacin

N C O F OH O OCH3 HN N

moxifloxacin

N O OH O HN N F

Macrolides and quinolones as cell-associated antibiotics

Aim of the study

amphiphilic antibiotics

• accumulating in eucaryotic cells
• considered as useful for treating intracellular infections
• known substrates of efflux pumps in bacteria

efflux from macrophages ? macrolides

• phenotypic characterization
• f the active efflux
• consequences for

intracellular activity quinolones

Aim of the study

amphiphilic antibiotics

• accumulating in eucaryotic cells
• considered as useful for treating intracellular infections
• known substrates of efflux pumps in bacteria

efflux from macrophages ? macrolides

• phenotypic characterization

phenotypic characterization

• f the active efflux
• f the active efflux
• consequences for

intracellular activity quinolones

Efflux pumps expressed in J774 macrophages

ABC multidrug transporters

ATP ADP MDR-1 (P-glycoprotein) MRP1-10 cationic amphiphiles anionic amphiphiles

How to inhibit ABC transporters ?

ATP ADP MDR-1 (P-glycoprotein) MRP1-10 cationic amphiphiles anionic amphiphiles

deoxyglucose NaN3

How to inhibit ABC transporters ?

OCH3 H3CO CN CH(CH3)2 N CH3 OCH3 OCH3 N H C O H N H3CO O N H3CO H3CO

ATP

verapamil

cationic amphiphiles MDR-1 (P-glycoprotein)

GF120918

ADP

How to inhibit ABC transporters ?

COOH S N O O C3H7 C3H7 N Cl S S HOOC N(CH3)2 O

ATP MRP1-10 anionic amphiphiles

probenecid

(CH2)3 C CH3 CH3 COOH H3C CH3

gemfibrozil MK571

ADP

Differential recognition by MDR pumps

Influence of ATP-depletion and pump inhibitors

• n accumulation at equilibrium

ciprofloxacin & MRP azithromycin & P-glycoprotein

• extracell. conc. 5 mg/L;

AZM 3 h; CIP 2 h Michot et al. AAC (2004) 48:2673-82

Aim of the study

amphiphilic antibiotics

• accumulating in eucaryotic cells
• considered as useful for treating intracellular infections
• known substrates of efflux pumps in bacteria

efflux from macrophages ? macrolides

• phenotypic characterization
• f the active efflux
• consequences for

consequences for intracellular activity intracellular activity quinolones

Models of intracellular infection

• L. monocytogenes
• S. aureus

phagolysosomes cytosol

Influence of pump inhibitors on intracellular activity

azithromycin and L. monocytogenes

• L. monocytogenes

verapamil 20 µM; 24 h

AZM

AZM Seral et al (2003) JAC 51:1167-73

Influence of pump inhibitors on intracellular activity

azithromycin and S. aureus

• S. aureus

AZM

AZM verapamil 20 µM; 24 h Seral et al (2003) JAC 51:1167-73

Influence of pump inhibitors on intracellular activity

ciprofloxacin and L. monocytogenes

• L. monocytogenes

gemfibrozil 250 µM; 24 h

CIP

Seral et al (2003) JAC 51:1167-73

Influence of pump inhibitors on intracellular activity

ciprofloxacin and S. aureus

• S. aureus

CIP

gemfibrozil 250 µM; 24 h Seral et al (2003) JAC 51:1167-73

Influence of pump inhibitors on antibiotic distribution

verapamil enhances azithromycin concentration In cytosol and vacuoles

• L. monocytogenes

AZM

AZM

• S. aureus

Seral et al (2003) JAC 51:1167-73

Influence of pump inhibitors on antibiotic distribution

gemfibrozil enhances ciprofloxacin cytosolic content

• L. monocytogenes

CIP

• S. aureus

Seral et al (2003) JAC 51:1167-73

Are these effects clinically-relevant ?

constitutive efflux makes AZM and CIP activity suboptimal in a clinically-meaningful range of concentrations

Aim of the study

amphiphilic antibiotics

• accumulating in eucaryotic cells
• considered as useful for treating intracellular infections
• known substrates of efflux pumps in bacteria

efflux from macrophages ? macrolides macrolides

• cellular pharmacokinetics
• model of interaction

with the transporters quinolones quinolones

Aim of the study

amphiphilic antibiotics

• accumulating in eucaryotic cells
• considered as useful for treating intracellular infections
• known substrates of efflux pumps in bacteria

efflux from macrophages ? macrolides

• cellular pharmacokinetics

cellular pharmacokinetics

• model of interaction

model of interaction with the transporters with the transporters quinolones

Kinetics of accumulation and efflux for azithromycin

accumulation markedly increased; efflux marginally affected

• extracell. conc. 5 mg/L; verapamil 20 µM

Seral et al (2003) AAC 47:1047-51

Kinetics of accumulation and efflux for ciprofloxacin

both accumulation and efflux markedly affected

• extracell. conc. 17 mg/L; probenecid 5 mM

Michot et al. AAC (2004) 48:2673-82

Kinetics of accumulation and efflux for moxifloxacin

neither accumulation nor efflux affected

• extracell. conc. 17 mg/L; probenecid 5 mM

Michot et al. AAC (2005) – in press

Quinolones as inhibitors of ciprofloxacin efflux

• ciprofloxacin efflux inhibited by ciprofloxacin

Michot et al. AAC (2005) – in press

Quinolones as inhibitors of ciprofloxacin efflux

• ciprofloxacin efflux inhibited by ciprofloxacin
• moxifloxacin not affected

Michot et al. AAC (2005) – in press

Quinolones as inhibitors of ciprofloxacin efflux

• ciprofloxacin efflux inhibited by ciprofloxacin

CIP CIP MXF

Michot et al. AAC (2005) – in press

Quinolones as inhibitors of ciprofloxacin efflux

• ciprofloxacin efflux inhibited by ciprofloxacin

moxifloxacin

CIP MXF

moxifloxacin also able to interact with the transporter !

CIP

Michot et al. AAC (2005) – in press

Comparison of kinetic parameters

influx efflux half-life (min) half-life (min) control inhibitor flux

(pmol/mg prot/min)

control inhibitor AZM 1 44 71 1 49 53 CIP 5 8 8 6 1.2 7.2 MXF 68 0.2 0.2 66 0.6 0.6 flux

(pmol/mg prot/min)

drug

Comparison of kinetic parameters

influx efflux half-life (min) half-life (min) control inhibitor flux

(pmol/mg prot/min)

control inhibitor AZM 1 44 71 1 49 53 CIP 5 8 8 6 1.2 7.2 MXF 68 0.2 0.2 66 0.6 0.6 flux

(pmol/mg prot/min)

drug

Comparison of kinetic parameters

influx efflux half-life (min) half-life (min) control inhibitor flux

(pmol/mg prot/min)

control inhibitor AZM 1 44 71 1 49 53 CIP 5 8 8 6 1.2 7.2 MXF 68 0.2 0.2 66 0.6 0.6 flux

(pmol/mg prot/min)

drug

Comparison of kinetic parameters

influx efflux half-life (min) half-life (min) control inhibitor flux

(pmol/mg prot/min)

control inhibitor AZM 1 44 71 1 49 53 CIP 5 8 8 6 1.2 7.2 MXF 68 0.2 0.2 66 0.6 0.6 flux

(pmol/mg prot/min)

drug

Comparison of kinetic parameters

influx efflux half-life (min) half-life (min) control inhibitor flux

(pmol/mg prot/min)

control inhibitor AZM 1 44 71 1 49 53 CIP 5 8 8 6 1.2 7.2 MXF 68 0.2 0.2 66 0.6 0.6 flux

(pmol/mg prot/min)

drug

Azithromycin, ‘kick-back’ model

Gaj et al. (1998) Biochem. Pharmacol. 55:1199-211

Ciprofloxacin, classical model

Kolaczkowski & Goffeau (1997) Pharmacol. Ther. 76:219-42

Moxifloxacin, ‘futile-cycle’ model

Eytan et al. (1996) JBC 271:12897-902

Conclusion

constitutive efflux of antibiotics in macrophages

pharmacokinetics: suboptimal cellular accumulation suboptimal intracell. activity pharmacodynamics:

resistance ?

wide spectrum transporters pharmacokinetics:

drug interactions ?

differences in affinity within a AB class pharmacology:

Questions for future research

? mechanism

• f

transport ? identification

• f

transporter cooperation with bacterial efflux pumps ? ? drug interactions metabolic alterations ?

Take home message

constitutive efflux is part of the game Take it into account in the choice of your « magic bullets » … for their optimal targeting

Thanks to Thanks to …

Thanks to Thanks to …

Evaluating magic bullets Evaluating magic bullets

• pharmacokinetics

pharmacokinetics H.

• H. Chanteux

Chanteux, M. , M. Heremans Heremans, J.M. , J.M. Michot Michot

• pharmacodynamics

pharmacodynamics

• M. Barcia, N.
• M. Barcia, N. Bles

Bles, S. , S. Carryn Carryn, S. , S. Lemaire Lemaire, ,

• A. Olivier, C.
• A. Olivier, C. Seral

Seral, S. Van de , S. Van de Velde Velde

• toxicodynamics

toxicodynamics J.P. J.P. Montenez Montenez, H. , H. Servais Servais, D. , D. Tyteca Tyteca

• biophysics

biophysics & molecular biology & molecular biology N.

• N. Caceres

Caceres, N. , N. Fa Fa

Thanks to Thanks to …

New magic bullets New magic bullets

• chemistry

chemistry E.

• E. Colacino

Colacino, C. , C. Dax Dax, L. , L. Efron Efron, T. , T. Happaerts Happaerts, M. , M. Renard Renard

• pharmacology

pharmacology I.

• I. Tytgat

Tytgat, D. Van , D. Van Ackeren Ackeren

• modeling

modeling M.

• M. Prévost

Prévost, M. , M. Rooman Rooman, S. , S. Vandevuer Vandevuer

Thanks to Thanks to …

Resistance to magic bullets Resistance to magic bullets

• efflux

efflux L.

• L. Avrain

Avrain, N. , N. Mesaros Mesaros

• glycopeptides

glycopeptides P.

• P. Courvalin

Courvalin and his team and his team

Thanks to Thanks to …

Clinical use of magic bullets Clinical use of magic bullets

• clinical pharmacy

clinical pharmacy E.

• E. Ampe

Ampe, V. , V. Basma Basma, A. , A. Spinewine Spinewine

Thanks to Thanks to …

Playing with magic bullets Playing with magic bullets

• technical staff

technical staff

• N. Aguilera, M.C.
• N. Aguilera, M.C. Cambier

Cambier, O. , O. Meert Meert, , F.

• F. Renoird

Renoird, M. , M. Vergauwen Vergauwen

• secretary

secretary M.

• M. Breugelmans

Breugelmans

Thanks to Thanks to …

Ehrlich’s colleagues Ehrlich’s colleagues

Thanks to Thanks to …

Inspiring research on magic bullets Inspiring research on magic bullets

Thanks to Thanks to …

Evaluating research on magic bullets Evaluating research on magic bullets

• P. Courvalin, A. Dalhoff, M. Delmée,
• P. Courvalin, A. Dalhoff, M. Delmée,
• H. Derendorf,Y. Glupczynski,
• H. Derendorf,Y. Glupczynski,
• E. Sonveaux, F. Zech
• E. Sonveaux, F. Zech

Thanks to Thanks to …

Paying for research on magic bullets Paying for research on magic bullets

Thanks to Thanks to …

Managing research on magic bullets Managing research on magic bullets

M.P. Mingeot M.P. Mingeot-

• Leclercq

Leclercq P.M. Tulkens P.M. Tulkens

Thank you Thank you for your attention for your attention