Inhibitors of Cell Wall Synthesis

Inhibitors of Cell Wall SynthesisPenicillinNatural penicillinsSemisynthetic penicillinsExtended-spectrum penicillins

PenicillinsLow toxicityEffective derivatives created from manipulating drugs basic molecular structureKills bacteria by preventing them from forming the rigid cell wallBecause human cells do not have cell walls, they are not affected

Therapeutic Uses of PenicillinsAbscessesBeta-hemolytic streptococcusMeningitisOtitis mediaPneumoniaRespiratory infectionsTooth and gum infectionsVenereal diseases (syphilis and gonorrhea)Endocarditis due to streptococci

Penicillins Side EffectsDiarrheaAllergies in 7% to 10% of population

Penicillins Dispensing IssuesTake on an empty stomachFood slows absorptionAcids in fruit juices or colas could deactivate the drug

The Structure of Penicillins

The Structure of Penicillins

Retention of Penicillin G

The Effect of Penicillinase on Penicillins

b-Lactam AntibioticsPenicillinPenicilinase-resistant penicillinsPenicillins + -lactamase inhibitorsCarbapenemsSubstitute a C for a S, add a double bondMonobactamSingle ring

Inhibitors of Cell Wall SynthesisCephalosporinsFirst-generation: Narrow spectrum, gram-positiveSecond-generation: Extended spectrum includes gram-negativeThird-generation: Includes pseudomonads; injectedFourth-generation: Oral

First-generationSimilar to penicillinase-resistant penicillins with greater gram-negative coverageUsed for community-acquired infectionsmild to moderate infectionsSecond-generationIncreased activity, especially against Haemophilus influenzaeUsed for Otitis media in childrenRespiratory infectionsUTIsThird-generationActive against a wide spectrum of gram-negative organismsLong half-life, so once-a-day dosing for someUsed forAmbulatory patientsChildren (dosing before or after school)

Inhibitors of Cell Wall SynthesisPolypeptide antibioticsBacitracinTopical applicationAgainst gram-positivesVancomycinGlycopeptideImportant "last line" against antibiotic-resistant S. aureus

Comparison of Cephalosporin and Penicillin

The Inhibition of Protein Synthesis by Antibiotics

Inhibitors of Protein SynthesisChloramphenicolBroad spectrumBinds 50S subunit; inhibits peptide bond formation

Inhibitors of Protein SynthesisAminoglycosidesStreptomycin, neomycin, gentamycinBroad spectrumChanges shape of 30S subunit

Inhibitors of Protein Synthesis

Inhibitors of Protein SynthesisStreptograminsGram-positivesBinds 50S subunit; inhibits translation

Inhibitors of Protein Synthesis

Inhibitors of Protein SynthesisOxazolidinonesLinezolidGram-positivesBinds 50S subunit; prevents formation of 70S ribosome

Inhibitors of Nucleic Acid SynthesisRifamycinInhibits RNA synthesisAntituberculosisQuinolones and fluoroquinolonesNalidixic acid: Urinary infectionsCiprofloxacinInhibits DNA gyraseUrinary tract infectionsQuinolonesStrong, rapid bactericidal action against most gram-negative and many gram-positive bacteriaAntagonize the enzyme responsible for coiling and replicating DNA, causing DNA breakage and cell death

Quinolones Dispensing IssuesNot to be given with theophyllineAntacids interfere with absorptionAvoid exposure to sun

Therapeutic Uses of QuinolonesBone and joint infections caused by gram-negative organismsInfectious diarrheaOphthalmic infectionsSome sexually transmitted diseasesUpper respiratory infectionsUTIs Quinolones Side EffectsPrimarily gastrointestinal, with nausea and vomitingDizzinessUnpleasant tasteCan cause joint problems such as swelling and malformationsPatients taking them have a tendency to injure tendons Rifamycinany of a family of antibiotics biosynthesized by a strain ofStreptomyces mediterranei,effective against a broad spectrum of bacteria, including gram-positive cocci, some gram-negative bacilli, andMycobacterium tuberculosisand certain other mycobacteria; used for the treatment oftuberculosis and the prophylaxis of meningococcal infections.Adverse reactions

CNS:ataxia, confusion, drowsiness, fatigue, headache, asthenia, psychosis, generalized numbnessEENT:conjunctivitis; discolored tears, saliva, and sputumGI:nausea, vomiting, diarrhea, abdominal cramps, dyspepsia, epigastric distress, flatulence, discolored feces, anorexia, sore mouth and tongue,pseudomembranous colitisGU:discolored urineHematologic:eosinophilia, transientleukopenia,hemolytic anemia, hemolysis, disseminated intravascular coagulation (DIC), thrombocytopeniaHepatic:jaundiceMetabolic:hyperuricemiaMusculoskeletal:myalgia, joint painRespiratory:dyspnea, wheezingSkin:flushing, rash, pruritus, discolored sweat,erythema multiforme, toxic epidermal necrolysis, Stevens-Johnson syndrome Other:flulike symptoms, hypersensitivity reactions including vasculitis prophylaxisrefers to medical or public health measures taken in order to prevent disease or health problems, rather than to treat or cure an existing condition.Prophylaxisis also a way to stem an outbreak of disease, or minimize the symptoms of someone who has been exposed to a disease or virus.