DR. MABANAG - CEPHALOSPORINS, CARBAPENEMS, MONOBACTAMS & BETA LACTAMASE INHIBITORS Flashcards
All cephalosporins have the same basic structure containing the _____________________which is a Dihydrothiazine ring attached to a β-lactam ring.
7-AMINOCEPHALOSPORANIC ACID NUCLEUS
● Very active vs. G(+) cocci: streptococci and staphylococci
● Limited activity vs G(-) such as Proteus mirabilis, E. coli, Klebsiella pneumoniae (Mnemonic: PEcKs first)
First Generation Cephalosporins
First Generation Cephalosporins
● Examples (Mnemonic: FADer, help me FAZ my PHarmacology exam)
○ CeFADroxil
○ CeFAZolin
○ CePHalothin
○ CePHapirin
○ CePHradine
○ CePHalexin
*WITH ADDITIONAL G- COVERAGE
○ H. influenza
○ Enterobacter
○ Neisseria
○ Proteus mirabilis
○ Escherichia coli
○ Klebsiella pneumoniae
○ Serratia marcescens
● Mnemonic: HEN PEcKs
Second Generation Cephalosporins
Second Generation Cephalosporins
FAMily FOX FURing TEa
○ CeFAMandole
○ CeFOXitin
○ CeFURoxime
○ CefoTEtan
Second Generation Cephalosporins
● Mnemonic: “FAC! LORA the PROfessional AZOLE is still on the FONe!”
○ CeFAClor
○ LORAcarbef
○ CefPROzil
○ CefmetAZOLE
○ CeFONicid
● Expanded G(-) coverage, some are able to cross BBB
● All penetrate well into the CSF, so for CNS infections these are usually used
ThirdGenerationCephalosporins
ThirdGenerationCephalosporins
● Mnemonic: “FEnge PO ng PERA to FIX my 3
(TRI) TTTTv”
○ CeFEtamet
○ CefPOdoxime
○ CefoPERAzone
○ CeFIXime*
○ CefTRIaxone
○ CefTazidime—most widely used in the
Philippines
○ CefoTaxime
○ CefTizoxime
○ CefTibuten
●P. aeruginosa
Enterobacteriaceae
methicillin-susceptible S. aureus
S. pneumoniae
● Penetrates well into the CSF
FourthGenerationCephalosporins
CEFEPIME
FourthGenerationCephalosporins
● added activity against MRSA
● Unlike 4th gen cephalosporin—no activity against P. aeruginosa
FifthGenerationCephalosporins
CEFTAROLINE
FifthGenerationCephalosporins
○ Both FDA-approved for treatment of complicated intra-abdominal infections & UTIs
○ Relatively new antibiotics
● Ceftolozane + Tazobactam
● Ceftazidime + Avibactam
These are the newer β-lactam inhibitors
● Tazobactam & Avibactam
used for brain infections because they penetrate well into the CSF
Cefuroxime, 3rd and 4th generation
cephalosporins
Used for treatment of UTI, staphylococcal and streptococcal infections including cellulitis and soft tissue abscess, surgical prophylaxis
FIRST GEN
Used primarily for sinusitis, otitis, LRTIs & community-acquired pneumonia
SECOND GEN
Used for serious infection requiring IV therapy (e.g. meningitis, neutropenic fever)
3RD GEN
Used for infections caused by Pseudomonas aeruginosa and Enterobacter
4TH GEN
Used for MRSA infection
5TH GEN - CEFTAROLINE
Used for treatment of complicated intra-abdominal infections and urinary tract infections
Cephalosporins + Beta-Lactamase Inhibitor
Adverse Reactions of Cephalosporins
ALLERGY
GI DISTURBANCES
HYPOPROTHROMBINEMIA & BLEEDING DISORDER
DISULFIRAM LIKE INFECTIONS (flushing, tachycardia, hypotension, nausea, dizziness) - Due to inhibition of the
enzyme acetaldehyde dehydrogenase
DRUGS THAT CAUSE THE DISULFIRAM-LIKE REACTIONS:
● Metronidazole
● Cefotetan
● Cefamandole
○ Cefotetan and Cefamandole are 2nd gen cephalosporins
● Cefoperazone (3rd gen cephalosporin)
● Disulfiram
● broadest-spectrum of all beta-lactam abx
○ Excellent activity against both Gram(+) and (-), aerobic and anaerobic bacteria
○ Good activity against Pseudomonas aeruginosa & Bacteroides fragilis (except Ertapenem)
‐ Does not have activity against MRSA
CARBAPENEMS
FIRST CARBAPENEM
inactivated dehydropeptidase in renal tubules, resulting in low urinary concentrations
○ Always administered together with an inhibitor of dehydropeptidase, Cilastatin, to prolong its half-life
IMIPENEM
competitive inhibitor of renal tubular
dehydropeptidase, resulting in the inhibition of cleavage of Imipenem
CILASTATIN
ADVERSE EFFECT OF CARBAPENEMS
-SEIZURE
-ALLERGY
-GI DISTRESS
● Include Aztreonam
● Drugs with Monocyclic β-lactam ring
● Spectrum: only active for G(-) aerobic rods
(Pseudomonas aeruginosa)
● Extremely resistance to β-lactamases
MONOBACTAMS
● These are added to β-lactam antimicrobials to counter the killing enzyme of bacteria.
Beta-Lactamase Inhibitors
Beta-Lactamase Inhibitors
INCLUDE THE FOLLOWING
- CLAVULANIC ACID
- SULBACTAM
- TAZOBACTAM
No antimicrobial activity
Most are against plasmid encoded β-lactamases and inactive against chromosomal β-lactamases Available only in flex combinations with a β-lactam antibiotic (specific Penicillins and Cephalosporins)
○ Piperacillin + Tazobactam (PipTazo)
○ Ampicillin + Sulbactam (AmpiSul)
○ Amoxicillin + Clavulanic acid
(Co-Amoxiclav)
Beta-Lactamase Inhibitors
type of drugs used to treat bacterial infections, especially those caused by G(+) organisms and enterococcal infections which are resistant to other antibiotics
GLYCOPEPTIDES
Mechanism of Action: Inhibitors of Cell Wall Synthesis
○ Work by inhibiting the cell wall synthesis of the bacteria
GLYCOPEPTIDES
1st Gen Glycopeptides
VANCOMYCIN
TEICOPLANIN
RAMOPLANIN
Has an important role because of its effectiveness vs multiple drug-resistant organisms
-MRSA
-ENTEROCOCCI
VANCOMYCIN
2nd Generation Glycopeptides:
(-VANCIN)
ORITAVANCIN
DALBAVANCIN
TELAVANCIN
○ Inhibits transglycosylation and
transpeptidation steps of cell wall biosynthesis
2nd Generation Glycopeptides:
ORITAVANCIN
DALBAVANCIN
TELAVANCIN
disrupts bacterial membrane integrity, while Dalbavancin does not.
ORITAVANCIN
GLYCOPEPTIDES: ADVANTAGES
-GIVEN SINGLE DOSE (2 DOSE-DALBAVANCIN)
-TARGET ACUTE BACTERIAL SKIN AND SKIN STRUCTURE INFECTION
-NO DRUG MONITORING
-CONVENIENT
GLYCOPEPTIDES: DISADVANTAGES
-VERY EXPENSIVE
-DELAYED HYPERSENSITIVITY
-TREATMENT FAILURE
-ADMIN.IV
Inhibits cell wall synthesis by interfering w/ 2nd stage of peptidoglycan synthesis–peptidoglycan polymerization
Vancomycin&1stGenGlycopeptides
like Vancomycin, mediates its antibacterial activity by binding to the D-alanyl-D-alain moiety and sequesters the lipid 2 substrate
○ Results in inhibition of bacterial peptidoglycan synthesis
TEICOPLANIN
blocks bacterial cell wall biosynthesis by interfering with peptidoglycan production
RAMOPLANIN
Mechanism of action distinct from glycopeptides:
‐ Does not complex with the D-alanyl-D-alanine sequence of cell wall precursor
RAMOPLANIN
IN ____ BACTERIA, Vancomycin binds to the transglycosylase enzymes = preventing the linkage of D-alanyl and D-alanine terminus of the cell wall precursor units = failure of the cross linkages between the two glycopeptide polymers
G+ BACTERIA
Has effectively been used against G(+) organisms Used in patients with
○ MRSA
○ MRSE (Methicillin-Resistant
Staphylococcus epidermidis)
○ Enterococci infections
Vancomycin:ClinicalUses
BACTERICIDAL
○ Infections by G(+) bacteria resistant to β-lactams
○ People with G(+) infections but allergic to β-lactams
VANCOMYCIN
Alternative drug in:
○ Staphylococcal Endocarditis
○ Methicillin-resistant infections
○ Enterococcal infections
○ Diphtheroid infections
○ Clostridium difficile colitis
VANCOMYCIN
Prophylaxis and treatment: For patients with prosthetic heart valves or patients to be implanted with prosthetic devices
VANCOMYCIN
Alternatives for Vancomycin resistance:
1. CYCLIC LIPOPROTEIN
DAPTOMYCIN
Alternatives for Vancomycin resistance:
Quinupristin-dalfopristin + Linezolid
● Plasmid-mediated changes in the permeability of the bacterial membrane to the drug
● Decreased binding to Vancomycin receptors
○ Due to the replacement D-alanyl-D-alanine lactate in molecules of resistant organisms.
VANCOMYCIN RESISTANCE
VANCOMYCIN ADVERSE EFFECTS
-IDEALLY IV SHOULD BE GIVEN VERY SLOWLY
● Effect manifesting as flushing and shock due to histamine release.
● Associated w/ rapid drug infusion.
RED-MAN SYNDROME
VANCOMYCIN ADVERSE EFFECTS
● Most essential and irreversible.
● Occurs in patients with renal impairment
● Hearing loss is permanent
● More common if administered
concomitantly with aminoglycosides
OTOTOXICITY
VANCOMYCIN ADVERSE EFFECTS
● Impure preparations.
● Occurs in patients with renal impairment
● More common if administered
concomitantly with aminoglycosides.
NEPHROTOXICITY
- NEWER DRUG
-AS EFFECTIVE AS VANCOMYCIN IN TREATINGS. AUREUS
*** LESS ADVERSE EFFECTS LIKE
1. SKIN RASHES
2. RED MAN SYNDROME
3. LESS DAMAGE TO THE KIDNEYS
TEICOPLANIN
● Cyclic lipopeptide antibiotic
● Alternative to vancomycin, linezolid, and
quinupristin/dalfopristin for tx of G(+) infections
○ Ex. MRSA or MRSE infections
**BACTERICIDAL
**SYNTHESIS = CELLMEMBRANE DEPOLARIZATION
**MOA = INHIBITOR OF CELLWALL
DAPTOMYCIN
Binds to the cytoplasmic membrane of bacteria →
results to rapid depolarization of the membrane → disrupting its functions and inhibiting DNA, RNA & protein synthesis
DAPTOMYCIN
DAPTOMYCIN ADVERSE EFFECTS
● Constipation, nausea, vomiting, headache, and insomnia
● LFTs [liver function tests] [and CPK [creatine phosphokinase] may ↑
● Discontinue concurrent statins
- Trimethoprim is a drug that targets which one of the 4 major categories of bacterial targets?
a. Cell Wall
b. Nucleic acid
c. Outer Cell Membrane
d. Ribosomes
B.NUCLEIC ACID
- All beta-lactams inhibit synthesis of the peptidoglycan layer by binding to and inhibiting the action of ___________ involved in the cross-linking of peptidoglycan chains.
a. Transketolase
b. Penicillinase
c. Transpeptidase
d. Beta-Lactamase
c. Transpeptidase
- T/F. Natural or Penicillinase-sensitive penicillins are active against both Gram(+) and Gram(-) rods, and anaerobes.
FALSE
- T/F. Antistaphylococcal Penicillins are active against Gram(-) bacteria and other classes of β-lactamase producing bacteria.
FALSE
- T/F. Aminopenicillins and antipseudomonal penicillins have greater activity against Gram(-) bacteria due to their enhanced ability to penetrate outer membranes.
TRUE
- All of the following are adverse effects of antistaphylococcal penicillins except:
a. Hepatitis
b. Interstitial nephritis
c. Myoclonic seizures
d. Neutropenia
c. Myoclonic seizures
- Which cephalosporin?
among the drugs is a fourth-generation
a. Cefaclor
b. Cefamandole
c. Cefixime
d. Cefepime
D. CEFEPIME
- Which of the following is an adverse effect of Daptomycin
a. Constipation, nausea, vomiting, headache, and insomnia
b. LFTs and CPK may increase
c. Discontinue concurrent statins
d. AOTA
D. AOTA
- Which of the following is true regarding Daptomycin
a. Increase dose in bacteremia
b. Decrease dose in bacteremia
c. Increase dose in endocarditis
d. Decrease dose in endocarditis
e. AandC
f. BandD
g. AandD
h. BandC
a. Increase dose in bacteremia
c. Increase dose in endocarditis
- In general, IV vancomycin should be given very slowly. If the infusion is fast, there is a risk of precipitating:
a. Purple-glove syndrome
b. Red-man syndrome
c. Blue-man syndrome
d. Red-glove syndrome
b. Red-man syndrome