Fundamentals of Pharmacology for Veterinary Technicians Chapter 14

Figure 14-8

Fundamentals of Pharmacology for Veterinary Technicians Chapter 14

Table 14-1

TABLE 14-1 Mechanisms of Action of Antibiotic Drugs

Action Effect Drug Examples

Inhibition of cell wall Bactericidal effect by penicillin, cephalosporin, synthesis inhibition of an enzyme in bacitracin, vancomycin

the synthesis of the cell wallAlteration in cell membrane Bacteriostatic or bactericidal polymyxin Bpermeability effect; as the membrane

permeability is increased, the loss of cellular substances causes cell lysis

Inhibition of protein Bacteriostatic or bactericidal aminoglycosides, synthesis effects due to interference tetracyclines, with bacterial protein chloramphenicol,

synthesis, but not animal cell florfenicol, macrolides, protein synthesis or inhibition lincomycinsof the steps of protein synthesis

I n t e r f e rence with Bacteriostatic effects due to sulfonamidesm e t a b o l i s m the deprivation of essential

material for bacterial metabolism

Nucleic acid impairment Bactericidal effects due to quinolones, inhibition of nucleic acid fluoroquinolonesenzymes

Fundamentals of Pharmacology for Veterinary Technicians Chapter 14

Table 14-2

TABLE 14-2 Classes of Antibiotics and Their Effectiveness.

Class of Antibiotic Action of Antibiotic ConsiderationsExamples

penicillins • Inhibit cell wall synthesis • Oral and injectable forms • penicillin V(V-Cillin K®),

• Bactericidal • Given orally, most absorption penicillin GProcaine

• Mainly work on gram + occurs in stomach and small (Crystacillin®), penicillin G

bacteria; some gram – with intestine Benzathinewith penicillin

amoxicillin, ampicillin, • Rapidly distributed G Procaine(Dual Pen®)

ticarcillin, carbenicillin, and • Give 1–2 hours before eating • amoxicillin(Amoxi-tabs®,

methicillin Amoxi-drops®, Biomox®, Robamox-V®)

• ampicillin(Polyflex®, Omnipen®)

• amoxicillinwith clavulinic acid(Clavamox®)

• ticarcillin(Ticar®)

• carbenicillin(Pyopen®, Geocillin®)

• cloxacillin(Dari-Clox®, Orbenin-DC®)

• dicloxicillin(Dynapen®, Pathocil®)

• hetacillin(Hetacin-K®)

• nafcillin(Nafcil®)

cephalosporins • Inhibit cell wall synthesis • Oral and injectable forms • Firstgeneration: cephapirin

• Bactericidal • GI absorption not good; (Cefa-Dri®,Cefa-lak®),

• First generation mainly work usually administered cephadroxil(Cefa-drops®,

on gram + bacteria, second parenterally Cefa-tabs®)through fourth generation • Well distributed to tissues, • Second

generation: work on gram + and gram – except CNS cefoxitin

Fundamentals of Pharmacology for Veterinary Technicians Chapter 14

Table 14-2 Continued

(Mefoxin®), bacteria • Vomiting may occur when cefaclor

(Ceclor®)given on empty stomach • Third

generation: ceftiofur • If animal is allergic to (Naxcel®)

penicillin, it will be allergic • Fourthgeneration:

to cephalosporin cefepime(Maxipime®)

polypeptides • Inhibit either cell wall or cell • Absorption is poor; used for • polymyxcin B(found in

membrane synthesis topical infections or wound Optiprime®ophthalmic

• Bactericidal lavage ointment)• bacitracin

(found inMycitracin®and Trioptic®ophthalmicointment)

aminoglycosides • Inhibit protein synthesis • Injectable form only • gentamicin(Gentocin®,

• Bactericidal • Not absorbed readily from Garacin®)• Work mainly on gram – GI tract; usually given • neomycin

(Biosol®, bacteria parenterally Mycifradin®)

• Nephrotoxicity and • amikacin(Amiglyde-V®,

ototoxicity concerns Amikin®)• Do not mix with penicillin in • tobramycin

(Nebcin®)the same syringe (makes •

dihydrostreptomycin penicillin inactive)

(Ethamycin®)

TABLE 14-2 Continued

Class of Antibiotic Action of Antibiotic ConsiderationsExamples

tetracyclines • Inhibit protein synthesis • Oral and injectable forms • tetracycline(Panmycin

• Bacteriostatic • Once given, quickly Aquadrops®,Oxy-Tet 100®

• Work on gram + and gram – distributed, sometimes to injectable,Tetracycline

bacteria, as well as rickettsial CNS HCl® solublepowder )

bacteria • Very little metabolism •oxytetracycline

Fundamentals of Pharmacology for Veterinary Technicians Chapter 14

Table 14-2 Continued

• Bind to calcium, causing side (Terramycin®,Liquamycin®)

effects (do not give with •chlortetracycline

dairy products or antacids/(Aureomycin®)

antidiarrheal drugs) • doxycycline(Vibramycin®,

• Can cause yellow Doxirobe®Gel)

discoloration of teeth due to • minocycline(Minocin®)

calcium binding

chloramphenicol • Inhibits protein synthesis • Oral, injectable, and ointment •chloramphenicol

• Bacteriostatic forms(Chloromycetin®, Viceton®,

• Works on gram + and gram – • Readily absorbed into tissues Amphicol®)bacteria as well as rickettsial • Side effect of bone marrow bacteria suppression makes use not

recommended

florfenicol • Inhibits protein synthesis • Injectable form • florfenicol(Nuflor®)

• Bacteriostatic • Well distributed in body; can achieve therapeutic levels in the CNS

macrolides • Inhibit protein synthesis • Well distributed to most body • tilmicosin(Micotil®)

• Bactericidal or bacteriostatic tissues, but not the CNS • tylosin(Tylan®)

• erythromycin(Erythro-100®,Erythro-Dry®)

lincosamides • Inhibit protein synthesis • Recommended for abscesses • clindamycin(Antirobe®)

• Bactericidal or bacteriostatic and dental infections • pirlimycin(Pirsue®)

• lincomycin(Lincocin®)

sulfonamides • Inhibit folic acid synthesis • Can have anti-inflammatory •sulfadiazine/trimethoprim

• Sulfonamides are effects (Tribrissen®)bacteriostatic • Well distributed through the •

sulfadimethoxine (Albon®)• Trimethoprim and body, including eye and CNS •

sulfadimethoxine/ormetroprim are bactericidal and synovial fluid ormetroprim

(Primor®)

Fundamentals of Pharmacology for Veterinary Technicians Chapter 14

Table 14-3

TABLE 14-3 Classes of Antifungals and Their Effectiveness

Class Mechanism of Action ConsiderationsExamples

polyenes Bind to fungal cell Not well absorbed; • a m p h o t e r i c i nB

membrane fairly toxic ( F u n g i z o n e ®)• nystatin

(Panalog®)

imidazoles Cause leakage of Less toxic; used for • ketoconazole(Nizoral®)

fungal cell membrane systemic mycotic • miconazole(Monistat,®

infections and some Conofite®)dermatophyte • itraconazole

(Sporanox®)infections • fluconazole

(Diflucan®)

Fundamentals of Pharmacology for Veterinary Technicians Chapter 14

Table 14-4

TABLE 14-4 Types of Disinfectants and Antiseptics

Disinfectant Group Product Examples Use ActionComments

phenols ortho-phenylpenol Laundry, floors, walls, Moderately bactericidal, •Action not affected

(Lysol®, Amphyl®), equipment virucidal, and fungicidal byorganic material;

hexachlorophene • Usedas a 2%–5% (Phisohex®)

solution on

contaminated objects

quaternary ammonium didecyl dimethyl Instruments, rubber, Moderately bactericidal, •Action not affected compounds ammonium chloride inanimate objects virucidal, and fungicidal byhard water

(Roccal®-D), benzalkoniumchloride (Zephiran®)

aldehydes gluteraldehydes Instruments Highly bactericidal, •Action not affected

(Cidex®, Glutarol®) virucidal, and fungicidal byorganic material

orhard water

ethylene oxide Rubber goods, blankets, Highly bactericidal, • “Gassterilization”

lensed instruments virucidal, and fungicidal forobjects that

cannot withstand heat

•Carefully read MSDS priorto handling

• Keepaway from