antibiotics

1. Antibiotics
- cell wall synthesis (Betalactam) inhibitors and polypeptide (Vancomycin)
Betalactam antibiotics- penicillin, cephalosporins, Monobactams, Carbapenems
Beta lactam antibiotics
Penicillin
Types MOA Coverage Side effects/ Special Topics
Natural Betalactam Penicillin
 Pen G (Benzyl penicillin)
- IV; Poorly absorbed from GIT
- IM (Benzathine)- given for
compliance measure due to depot
effect
 Pen V (Phenoxymethyl
Penicillin)
- Oral (V- Vunganga)
- acid stable
Interfere transpeptidation and
cross linking of peptidoglycan
chains
 Gram +
 No Gram (-) coverage except
Neiserria meningitidis,
Treponema and Leptospira
 A little of anaerobes except
Bacteroides (not to be given
in intra-abdominal infection)
Penicillinase enzyme- mostly produced by Staph. Aureus
- break the beta-lactam ring
Anti staphylococcal Penicillins
 Methicillin
MSSA  Interstitial Nephritis (reason why it
was phased out)
MRSA- cause by mutation mec- A gene/
cassette

2. - Change the PBP to PBP 2A causing the
B-Lactam loss its affinity.
- DOC: Community-acquired
(Clindamycin)
Hospital-aquired (Vancomycin
 Nafcillin MSSA  Reversible aggranulocytosis
 Hepatoxicity
 Isoxazoyl Penicillin
- Oxacillin, Cloxacillin, Dicloxacillin
Best treatment for staphylococcal
infection
Like IMPETIGO
Aminopenicillin
 Ampicillin- parenterally; poor
GI absorption; Frequently
combined with aminoglycoside
(Amikacin or gentamicin)
because of synergism
 Amoxicillin- better GI
absorption
 Gram +
 Gram -
 Little of anaerobes except
Bacteroides fragilis
Antipseudomonal Penicillins
 Carboxypenicillins
- Carbenicillin, Ticarcillin
 Ureidopenicillin
- Piperacillin (Most potent)
- Azlocillin
-Mezlocillin
 Pseudomonas Aeroginosa
Beta-lactamase Inhibitors
- Clavulanic acid
co-administered with beta-lactam
antimicrobials to prevent
 Gram +
 Gram -

3. - sulbactam
- tazobactam
antimicrobial resistance by
inhibiting serine beta-lactamases,
which are enzymes that inactivate
the beta-lactam ring, which is a
common chemical structure to all
beta-lactam antimicrobials
 Anaerobes including
Bacteroides fragilis
Cephalosporins
Generation Drugs Coverage
First Generation -CEPH including
Cefalexin (formerly cephalexin)
Cefazoline
Cefadoxil
Gram + plus PEK
P- Proteus
E- E.coli
K- Klebsiella
Second generation -CEF followed by a VOWEL
Including, META PRO
*CefPROzil
*CefMETAzol
And LORAcarbef
Gram +
HEN- Haemophilus influenzae, Enterobacter, Neiserria
PEK
Anaerobes
Third Generation -CEF Plus Consonant including
PERA, TAXes and FIXers
*CefoPERAzone
*CefoTAXime
*CeFIXime
And Moxalactam
Gram -
HEN
PEK
Plus SSS- Serratia, Salmonella, Shiegella
Pseudomonas- Ceftazidime, Cefoperazone only
Fourth Generation Cefipime
Cefpirone
3rd Gen coverage + Pseudomonas
Fifth Generation The Bothers ROLI and TOBI 4th Generation Plus MRSA

4. CeftaROLIne
CefTOBIprol
Monobactams
 Astreonam- only IV
Same coverage with Ceftazidime (3rd gen coverage + pseudomonas)
S/e: No- cross sensitivity
ADR: Transaminitis-> Drug induced hepatitis (Increase AST, ALT)
Carbapenems- sulfur atom in the
Thiazolidine ring was replaced by
CARBON atom
COVERAGE
- Gram +, gram -, Anaerobes, Pseudomonas aeroginosa (except ERTAPENEM)
-ALL are epileptogenic but IMEPENEM is more pronounced.
- Imepenem is degraded by dehydropeptidase enzyme at renal tubule thus added with CILASTIN (prolongs
Imepenem effects)
-tx for ESBL infection
- Doripenem- best coverage for pseudomonas
Polypeptide antibiotics
Vancomycin
Others: Televancin, teicoplanin
MOA: inhibits cell wall synthesis by binding to D-ala-ala- terminus thereby inhibiting transglycosylation furthering subsequent transpeptidydation 0r
cross-linking
* Vancomycin DOC for hospital-acquired MRSA and PSEUDOMEMBRANOUS Colitis (ORAL)
In PH we used METRONIDAZOLE for Pseudomembranous colitis
ADR:
* REDMAN or RED neck syndrome- erythematous rash; This is INFUSION RElated
- SLOW the infusion
- Hydrate the patient
- give Antihistamines- Cetirizine->Diphenhydramine->Steroids
*Nephrotoxic
- Vancomycin trough level must be requested, the lowest possible dose to have its effects.

5. POLYMIXINS
- cell membrane inhibitors
-cationic detergents
-never a drug of choice
-last line
- not as a monotherapy (combined with betalactam and aminoglycoside
Polymixin B Topical
B- Bilat JOKE!!!! BALAT
Polymixin E
Colistin
Parenteral
PROTEIN SYNTHESIS INHIBITORS
- targets translation; ALL Protein SYNTHESIS Inhibitors are Bacteriostatics except AMINOGLYCOSIDES
REMEMBER: Buy AT 30 SELL CC at 50
30 S- Aminoglycosides, Tetracyclins
BLOCKS 30S->blocks formation of initiation complex-> blocks translation-> mRNA misreading
Aminoglycosides
- MYCIN- from Streptomyces
*Neomycin
*Tobramycin
*Streptomycin
- MICIN- from Microminispora
*Gentamicin
*AMikacin
- BACTERICIDAL
- Polar- No oral absorption
- ALL must be given PARENTERALLY to achieve adequate serum levels except NEOMYCIN (topical or oral)
- synergistic with BETA-LACTAM, do not combine in 1 contaniner (Beta lactam first then aminoglycoside)
-ADR: NEPHROTOXICITY, VESTIBULOTOXICITY, OTOTOXICITY (only in high frequency sounds)
OTOTOXIC- Neomycin> Amikacin> Kanamycin (sino ang inuoto? aNAK)
VESTIBULOTOXIC- Streptomycin, Gentamicin
NEPHROTOXIC- Neomycin, Tpbramycin, Gentamicin
- Tobramycin- most toxic
-COVERAGE:
* Gram + except strep pneumoniae

6. * Gram -
* Pseudomonas
* No coverage for atypical and anaerobes
Tetracyclines- bacteriostatic
Short acting
* Tetracycline
* Chlortetracyclines
* Oxytetracycline
Intermediate
* Demeclocycline
*Methacycline
Long-acting- DoMino
*Doxicycline
*Minocycline
Pharmacokinetics
Absorption impaired by food
(except doxycycline,
minocycline), antacids, dairy
products, and divalent cations
(Ca2+, Mg2+, Fe2+),
or Al3+ due to COMPLEX
FORMATION/ CHEILATION
*Separate atleast 2 hours for
gastric emptying
· High protein-binding
· Widely distributed to tissues
except CSF
· Excellent intracellular
penetration
· Excreted in bile and urine
except Doxycycline
(bile only not renally
excreted)
· Can pass the placenta,
excreted in milk
Coverage:
Gram +
Gram -
Atypical organism (leigionella, chlamydia, leptospira, vibrio, borelia- DOC
Anaerobes
(-) coverage for Pseudomonas aeroginosa
BROADEST spectrum
TIGECYCLINE- COVERS everything except 3PM
3P- Pseudomonas, proteus, providencia
L- Morganella
ADR: Straining TET (Teeth)
Enamel hypoplasia
Bone deformity/ growth retardation
Avoid in children <8 years old
50 S SUBunits- SELL CC at 50
Streptogramins
Erythromycin and other macrolides

7. Lincosamides
Linzezolides- Chloramphenicol, Clindamycin
Macrolides
-thromycin
RACE
Roxitromycin
Azithromycin- only macrolide using
concentration dependent reaction
Clarithromycin
Erythromycin
Coverage:
Gram +
Gram -
Atypical
NO COVERAGE for Pseudomonas and Anaerobes
SUBSTITUTE for PENICILLIN allergies
ADR: Erythromycin- GI disturbances, motilin release
Lincosamide
* Lincomycin
- sulfur containing antibiotics
- notorious in causing Steven Johnson Syndrome
*Clindamycin Coverage
- Gram positive
- Community acquired MRSA
- Anaerobes
* above respiratory diaphragm except brain: CLINDAMYCIN
* below the respiratory diaphragm including the brain: METRONIDAZOLE
ADR: most commonly cause Pseudomembranous colitis ( due to prolong and/0r multiple antibiotics)
Tx: Oral Vancomycin, or metronidazole

8. Chloramphenicol - second line drugs due to BONE MARROW SUPPRESSION/ myelosuppresion-> Aplastic ANEMIA
- ADR: GRAY BABY SYNDROME- baby appears cyanotic (dose= <50mg/kg/day)
Due to impaired glucorinidation reaction due to lack of UDP- glucoronosyl transferase in infant.
-in INFANT drug metabolism is only via SULFATION
NUCLEIC ACID SYNTHESIS Inhibitors
- TMP- Sulfamethoxazole or Co- Trimoxazole
Co-timoxazole Mechanism of action
Dihydropteroate synthase Dihydrofolate reductase
(Sulfonamide acts here) (TMP acts here)
PABA--------------------------> Dihydrpfolic acid----------------------------> Tetrahydrofolic acid--------> Purine----> DNA
DRUG of CHOICE for:
Stenotrophomonas maltophilia
Burkholderia cepacian
Pneumocystis jeroveci pneumonia
Toxoplasma gondii
OTHER diseases: ONLY as SECOND LINE
ADR:
*Bleeding and KIDNEY OBSTRUCTION (Crystalluria)
* CRYSTALLURIA: Acidic Urine, High Urinary Concentration, Low Solubility
* Agranulocytosis
*hemolytic anemia: C/I in G6PD deficiency
*Kernecterus
*STEVEN JOHNSON SYNDROME

9. - Interfere in TOPOISOMERASE II and IV----> increase supercoiling-----> bacterial DNA will be fragile-----> DNA Damage
- TOPOISOMERASE- relieve Supercoiling
- BACTERICIDAL
-Coverage: Gram positive, gram negative, ATYPICAL, anaerobe (only in MOXIfloxacin), Pseudomonas aeroginosa (ONLY CIPROFLOXACIN and LEVOFLOXACIN)
- Respiratory fluoroquinolones: MOXIfloxacin, LEVOfloxacin, GATIfloxacin
- ADR: HYPERGLYCEMIA (except GATIFLOXACIN but causes HYPOglycemia), Arthropathy, QT-prolongation