Please enable JavaScript.

Coggle requires JavaScript to display documents.

PENICILLINS - Coggle Diagram

- - - - Altered target proteins→ low affinity for penicillin
        
        Pneumococci-highly resistant
        
        MRSA: acquired PBP with low affinity for ß lactam antibiotics
        
        Low level penicillin resistant gonococci→ less permeable to drug
        
        Poor penetration/ drug permeability : Only in G-ve bacteria
- - - - Use:
        
        Oxacillin & Nafcillin 8-12g/d given by intermittent IV infusion of 1-2g every 4-6 hrs→ DOC for staph. endocarditis
  - - - AMOXICILLIN
        
        Close congener
        Similar in all aspects except:
        
        Better oral abs., food does not interfere
        
        Higher & more sustained blood levels
        
        Amoxicillin 3x/day= Ampicillin 4x/day
        
        Diarhea↓
        
        Less active against Shigella & H.influenzae
        
        More active against penicillin resistant Strep. pneumoniae
        
        Use
        
        Bronchitis
        
        UTI
        
        SABE
        
        Gonorrhea
        
        Component of triple drug H.pylori regimen
      - AMPICILLIN
        
        Antibacterial spectrum:
        
        Both G+ & G- : streptococci, meningococci, pneumococci, enterococci, gonococci are sensitive
        
        H. influenzae, E.coli, Proteus, Salmonella, Shigella, H.pylori
        
        Less active against other G+ cocci
        
        Spectrum can be widened by adding a ß actamase inhibitor
        
        PHARMACOKINETICS
        
        Acid resistant
        
        Oral abs. incomplete but adequate
        + Food interferes with abs.
        
        Partly excreted in bile & reabsorbed→ enterohepatic circulation
        
        Excrn: kidney
        
        T½ ↑ in renal failure
        
        USES
        
        :check:Resp. tract infections: bronchitis/ otitis/ sinusitis respond
        
        UTI: earlier DOC, now not used
        
        :check:Meningitis : 1st line drug, given with 3rd gen cephalosporin→ empirical therapy
        ○ Many organisms now resistant to ampicillin
        
        :check:Gonorrhea: one of the 1st line drugs
        ○ Oral trt. of non-penicillinase producing gonococcal infections
        ○ Single dose 3.5g Amp+ 1g probenecid : Urethritis
        
        :check:Cholecystitis: preferred drug. ↑ conc. in bile
        
        SABE:
        ○ Amp. 2g IV 6 hrly
        
        :check:H.pylori: amoxicillin preferred
        
        :check:Septicemias d/t G-ve:
        ○ Amp.+ gentamicin / 3rd gen cephalosporin
        
        :check:A/c necrotizing ulcerative gingivitis: Ampicillin/amoxicillin + metronidazole
        
        :check:Typhoid, dysentery: rarely used now d/t resistance
        
        ADVERSE EFFECTS
        :forbidden:
        
        Diarrhea d/t irritation of gut by unabsorbed drug
        
        Skin Rashes esp. in patients with AIDS/ EBV inf/ lymphatic leukemia
        ○ Concurrent admn. of allopurinol also ↑ rashes
        
        Not to be given to patients with immediate type of HS to PnG
        
        INTERACTIONS
        
        Hydrocortisone inactivates ampicillin if mixed in IV soln.
        
        Interfere with deconjugation & enterohep. cycling of OCPs→ failure of OC
        
        Probenecid ↓ renal excrn of ampicillin
      - BACAMPICILLIN
        
        Ester prodrug of amp.
        
        Nearly completely absorbed from GIT
        
        Largely hydrolysed during absorption
        
        Longer acting
        
        ↓ diarrhea
        
        Dose: 400-800mg BD
      - Fixed Dose combination of Ampicillin/amox.+ Cloxacillin
        
        For post op infections
        
        Not synergistic combination
        
        Reduced efficacy nd chance of selecting resistant strains
        
        Now banned in India
    - - CARBENICILLIN
        
        Antibiotic spectrum: G+ & G-ve
        ○ Eff. against Pseudomonas aeruginosa & Proteus infections
        
        Not penicillinase resistant
        
        Inactive orally, rapidly excr. in urine
        
        Used as Na salt
        
        Dose: 1-2g IM or 1-5g IV every 4-6hrs
        
        Adverse Effects
        
        At higher doses, the excess Na⁺ → fluid retention, CHF in cardiac/renal patients
        
        High doses→ bleeding d/t interference with platelet dysfn.
        
        Uses
        
        Pseudomonas/ proteus infections
      - TICARCILLIN
        
        Similar but more active & less ADR
        
        For pseudomonas & proteus inf.
        
        Ticarcillin+ clavulanic acid→
        ○ Extend efficacy
        ○ Cover ß lactamase producing strains
        
        Serious pseudomonas inf→ ticarcillin+ gentamicin
    - - PIPERACILLIN
        
        Antipseudomonal penicillin
        
        8x more active than carbenicillin
        
        Antimicrobial spectrum
        ○ Wide spectrum
        ○ Eff against many G-ve org:
        ○ Klebsiella, enterobacteriaceae, bacteroides, proteus, H. influenzae
        
        Their Na⁺ content is low
        
        Uses
        
        For treating serious G-ve inf. in neutropenic/ immunocompromised/ burns patients
        
        Crosses BBB→ used in meningitis
        
        Combined with tazobactam to cover ß lactamase producing strains
        
        Concurrent use of gentamicin/ tobramycin
        
        Dose: 100-150mg/kg/day in 3 divided doses IM/IV
- - - - ADVERSE EFFECTS
        
        Pain @ site of inj.
        
        Thrombophlebitis
        
        Rash & diarrhea