Penicillins Flashcards
What is the basic structure of a penicillin?
- Thiazolidine ring
- B-lectam ring
- One “R” group
What are penicillins susceptible to?
Susceptible to bacterial metabolism and inactivation by amidases/lactamases
Which Beta-lactam has different stereochemical configuration in the ring that imparts resistance to most common B-lactamases?
Carbapenems
What is the general AE of penicillins?
N/V/D
If you’re taking penicillin, low concentrations are found where?
- Prostate
- CNS
- Intraocular
If you’re taking penicillin, high concentrations are found where?
- Urine
2. Bladder
What is the half-life of penicillin?
30-90minutes
What are the narrow spectrum penicillins?
Pen G/V
What are the penicillinase-resistant penicillins?
- Dicloxacillin
- Nafcillin
- Oxacillin
What are the antipseudomonal penicillins?
- Piperacillin w/ tazo
2. Ticarcillin w/ clav
What kind of bacteria does Pen G/V cover?
G+, mainly strep
How would you synthesize a penicillinase-resistant penicillin from a narrow spectrum penicillin?
Add isoxazolyl side group to protect B-lactam ring from hydrolysis
What kind of bacteria does penicillinase-resistant penicillin cover?
Same as Pen G/V, but also staph
How would you synthesize an extended spectrum penicillin from penicillinase-resistant penicillin?
Add amino group; this increases hydrophilicity so that RX can go thru porins of some G-
What kind of bacteria does extended spectrum penicillin cover?
Same as Pen G/V, but some G- and anaerobes
Of the subgroups of extended spectrum penicillin, which one has more of an advantage?
Antipseudomonal penicillins are better than aminopenicillins because they have additional coverage such as Proteus
Penicllins
- Narrow
- Narrow, but Penicillinase-R
- Aminopenicillins
- Anti-pseudomonal
Which one covers both Strep and Staph?
Narrow, but Penicillinase-R
Penicllins
- Narrow
- Narrow, but Penicillinase-R
- Aminopenicillins
- Anti-pseudomonal
Which one covers T. pallidum?
Narrow
Penicllins
- Narrow
- Narrow, but Penicillinase-R
- Aminopenicillins
- Anti-pseudomonal
Which one covers Pseudo and Proteus infections?
Anti-pseudomonal
Penicllins
- Narrow
- Narrow, but Penicillinase-R
- Aminopenicillins
- Anti-pseudomonal
Which one is effective against MSSE?
Both Narrow
+ Narrow, but Penicillinase-R
Penicllins
- Narrow
- Narrow, but Penicillinase-R
- Aminopenicillins
- Anti-pseudomonal
Which one is effective against MSSA?
Narrow, but Penicillinase-R
What are the skin tests used to detect allergic rxns to cephalosporins?
There are none lol
What is an important fact about a penicillin allergy with drug fever or rash?
May safely give another B-lactam
What is an important fact about a penicillin allergy with hives or anaphylaxis?
- IgE mediated
- Do NOT give B-lactam with potential cross-reactivity**
**Aztreonam does not display cross-reactivity and can be used
