Doctor of physiotherapy. Pharmacology

1. Other Beta Lactam
Drugs
PRESENTED BY
YASIR REHMAN
DPT 3RD YEAR

2. Introduction To Beta Lactam Drugs
 Penicillins and cephalosporins are the major antibiotics that inhibit
bacterial cell wall synthesis. They are called beta-lactam drugs
because of the unusual 4 member ring that is common to all of their
members.
 The beta lactams include some of the:
i) most effective
ii) widely used
iii) and well tolerated agents available for the treatment of
microbial infections.

3. Introduction To Beta Lactam Drugs
 Vancomycin
 Fosfomycin
 Bacitracin also inhibit cell wall synthesis but are not as important as
beta-lactam drugs.
 Daptomycin, an alternative to vancomycin.
 More the 50 antibiotics that act as cell wall synthesis inhibitors are
currently available, with individual spectra of activity that afford a
wide range of clinical applications.

4. Introduction To Beta Lactam Drugs

5. Other Beta-Lactam Drugs
A) AZTREONAM
 Aztreonam is a monobactam that is resistant to beta-lactamases
produced by certain Gram-negative rods, including Klebsiella,
pseudomonas and Serratia.
 It is an inhibitor of cell wall synthesis, preferentially binding to a
specific penicillin-binding protein(PBP3), and is synergistic with
aminoglycosides.
 Aztreonam in administered intravenously (IV).
 Eliminate via renal tubular secretions.
 Its half life is prolonged in renal failure.

6.  ADVERSE EFFECTS
i) GIT upset
ii) vertigo
iii) headache
iv) hepatotoxicity
v) skin rashes

7. B) Imipenem, Doripenem, Meropenem, and Ertapenem
 These drugs are carbapenems (chemically different from penicillin
but retaining the beta lactam ring structure) with low susceptibility
to beta-lactamases.
 They have wide activity against Gram-positive cocci, Gram-negative
rods and anaerobes.
 The carbapenems are administered parenterally and are useful for
infections caused by organisms resistant to other antibiotics.
 Carbapenems are currently co-drugs of choice for infection caused
by Enterobacter, Citrobacter, and Serratia species.

8.  Imipenem is rapidly inactivated by renal dehydropeptidase I and is
administered with cilastatin, an inhibitor of this enzyme.
ADVERSE EFFECTS OF IMIPENEM- CILASTATIN
i) GIT distress
ii) skin rashes
iii) very high plasma level
iv) CNS toxicity( confusion,
encephalopathy and seizures)
 Meropenem is similar to imipenem except that it is not metabolized
by renal dehydropeptidase and is less likely to cause seizures.
 Ertapenem---- long half life
Intramuscular injection cause pain and irritation.

9. C) Beta-Lactamase inhibitors
 Clavulanic acid
 Sulbactam
 Tazobactam are used in fixed combinations with certain hydrolysable
penicillins.
 They are more active against plasmid-encoded beta-lactamases.

10. A. VANCOMYCIN
B. FOSFOMYCIN
C. BACITRACIN
D. CYCLOSERINE
E. DAPTOMYCIN
OTHER CELL WALL OR MEMBRANE ACTIVE AGENTS

11. A) Vancomycin
 Vancomycin is a bactericidal glycoprotein that binds to the D-Ala-D-
Ala terminal of nascent peptidoglycan pentapeptide side chain and
inhibits transglycosylation.
 Vancomycin has a narrow spectrum of activity.
 Used for serious infections caused by drug-resistant Gram-positive
organisms including methicillin-resistant staphylococci(MRSA).
 Vancomycin is not absorbed from the GIT and may be given orally
for bacterial enterocolitis.
 Dosage modification is mandatory in patients with renal impairment.

12. Toxic effects
 Chills
 Fever
 Phlebitis(inflammation of vein)
 Ototoxicity( effect on auditory and vestibular system of inner ear)
 Nephrotoxicity ( harmful effects of substance on kidney)
 Rapid intravenous infusion may cause diffuse flushing (red man
syndrome) from histamine release.

13. B) Fosfomycin
 Fosfomycin is an antimetabolic inhibitor of cytosolic enolpyruvate
transferase.
 This action prevents to the formation of N-acetylmuramic acid.
 Fosfomycin is excreted by kidney.
 In a single dose, the drug is less effective than a 7-day course of
treatment with fluoroquinolones.
 Multiple dosing emerges rapidly and diarrhea is common.
C) Bacitracin
 Peptide antibiotic that interferes with a late stage in cell wall synthesis
in gram positive organisms.

14. D) Cycloserine
 Cycloserine is an antimetabolite that blocks the incorporation of D-Ala
into a pentapeptide side chain of the peptidoglycans.
 Cycloserine is only used to treat tuberculosis caused by organisms
resistant to first line antituberculosis drugs.
E) Daptomycin
 Daptomycin is a novel cyclic lipopeptide with spectrum similar to
vancomycin.
 The drug inserts into the cytoplasmic membrane, causing potassium
leak and cell death.
 Daptomycin is eliminated via kidney.