This is a draft cheat sheet. It is a work in progress and is not finished yet.
Penicillin
Natural |
Semisynthetic |
Ampicillin ester/prodrug |
Active agansit pseudomonas |
1. Benzyl penicillin (penicillin G) |
1. Ampicillin & Amoxycillin |
Bacampicillin |
Carbenicillin-Ticaricillin-Sulbenicillin |
Not suitable orally; Resistance occurs; narrow spectrum to G+ |
Orally active due to EWG on acylamino side chain. |
Ester from COOH prevents its ionization-->increased apsorption |
Have COOH (acidic/polar)gp that increases G- activity. |
Can be in salts with organic amines to have longer duration but only IM: |
2. Methicillin-Nafcillin-oxacillin |
Broken down into active form in bacteria by estrase. |
Ester prodrugs can be formed to increase oral activity. |
Procaine penicillin: 12 Hr |
B-lactamase resistant penicillin by R being a bulky gp that stearic hindrance preventing attachment of B-lactamase. |
Benzathine penicillin: 2-3 weeks |
Methicillin & Nafcillin: Orally inactive. |
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Oxacillin(s): B-lactamase resistant + orally active |
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Temocillin: strong B-lactamase resistance but only parentral route. |
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3. Ampicillin & amoxicillin |
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Broad spectrum (on G- too) because of a-amino gp as EWG and increasing hydrophilicty. |
B-lactamase inhibitors
Clauvulinic acid-sulbactam |
Have a B-lactam ring but irreversibly alkylate the B-lactamase enzyme in a mechanism based inhibition. |
Augmentin: Amoxicillin + Clavulinic acid |
Unacyn: Ampicillin + sulbactam |
Tetracyclines
Sancycline |
Democlocycline |
Minocycline |
Rolitetracycline |
Natural parent compound; no clinical benefit |
Natural, stable |
Semisynthetic |
Prodrug of N-mannich base of tetracycline |
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Starting compound for minocycline semi-synthesis |
-For red-bumbs and pimples |
Semisynthsis with tetracycline in a mannich reaction. |
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-For bacterial infections |
- More soluble and less irritating than others so suitable as IV and IM |
Glycylcyclines
New class; lack the clinical resistance issues of tetracyclines |
Tigecycline "tygacil": broad spectrum |
used for complicated intra-abdominal infections |
Macrolide antibiotics
Large lactone ring of 12-17 atoms (macrolide) with 2 characteristic sugars attached to a 14-membered ring. |
Erythromycin: Given as a film coated tablet to avoid GI acid causing hemiketal formation. can also be given in iral suspension as erythromycin stearate salt. |
Clarithromycin: more acid stability. |
Azithromycin/Azalide: from semi-synthetic ring expansion of erythromycin in a Beckmann rearrangement. |
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Cephalosporins
Gen 1 |
Gen 2 |
Gen 3 |
Gen 4 |
Cepalexin |
Cefaclor |
Ceftibuten |
Cefpirome & Cefepime |
7-ADCA deriv. |
7-ADCA deriv. |
7-ADCA |
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Orally active |
Orally active |
Orally active |
Parenteral only |
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Cefuroxime |
B-lactamase resistant |
B-lactamse resistant |
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7-ACA deriv. |
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Broad spectrum activity including p.aueroginosa, G+ and G-. |
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Not orally active (parenteral) |
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Prodrug: Cefuroxime axetil |
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COOH becomes an ester with axetil gp that increases lipophilicty--> better oral bioavialability |
Carbapenems
Thienamycin |
Imipenem |
Meropenem |
Biapenem |
Doripenem |
B-lactamase resistant: Alpha-hydroxyethyl side chain at position 6. |
Semisynthetic; is a N-formimino thienamycin that's chemically stable . |
Synthetic |
2nd gen carbapenems |
Newest |
Natural, broad spectrum, B-lactamase resistant and inhibitor |
Taken with Cilastatin: a DHP-1 inhibitor (enzymatica stability) |
No cilastatin needed with it due to side gp on position 3 and 4. |
Broad spectrum; DHP-1 stable & B-lactamase resistant |
Broad spectrum;DHP-1 stable & B-lactamase resistant |
Unstable; Susceptible to in-vivo deactivation by DHP-1 (t1/2=30sec) |
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Parenteral |
Parenteral |
Parenteral |
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For meningitis, sepsis, pneumonia, intrabdominal infection and anthrax |
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Potent against pseudomonas. |
Aminoglycosides/aminocyclitols
protein synthesis inhibitors. |
Water-soluble that must be given parenteral for systemic effect but can be given orally for a local GIT anti-septic effect. |
Streptomycin |
Drug-drug interaction: |
Aminoglycosides + B-lactam= inactive compound that results in hearing loss, ototoxicity & nephrotoxicity. |
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