Beta lactams Flashcards
Name the beta lactam agents
Penicillins Cephalosporins Monobactams Carbapenems B-lactamase innhibitors
Are beta lactams bacteriostatic or bacteriocidal?
Bacteriostatic
What organisms do beta lactams target?
Gam + and gram -
Name the natural penicillins
Penicillin V
Penicillin G
Are the natural penicillins oral or IV?
Penicillin V is oral
Penicillin G is parenteral
What do the natural penicillins target?
Streptococcal and sensitive pneumococcal infections
Pen G drug of choice for syphillis
What are the penicillinase resistant penicillins?
Dicloxacillin
Nafcillin
Oxacillin
What do the penicillinase resistant penicillins target?
They target penicillinase producing staphylococcal infections, MSSA
What are the broad spectrum penicillins?
Ampicillin
Amoxicillin
Amoxicillin + Clavulanate
Ampicillin + Sulbactam
What do the broad spectrum penicillins target?
S pyrogens H influenzae S pneumoniae N meningitidis induced meningitis Uncomplicated UTI
Which agents increase gram negative activity? Why is this helpful?
Antipseudomonal penicillins increase gram negative activity, allows them to target pseudomonas (P. aeruginosa, proteus, Enterobacter)
Piperacillin
Ticarcillin + Clavulanate
Piperacillin + Tazobactam
What is the broadest spectrum penicillin available?
Piperacillin + Tazobactam
How are penicillins absorbed?
They have good acid stability (except pen G) so they are absorbed orally
Absorption is DECREASED by food
How is penicillins solubility?
Poor lipid solubility (limited)
But they distribute well into the tissues
How are penicillins excreted?
Elimination is by active tubular secretion in the kidneys (90% unchanged in urine)
Anti-staph PCN’s are also in the bile
True or false: Penicillins are safe in nursing mothers
False - they cross the breast milk
How can you increase blood conc of penicillins?
Give probenecid to block active transport in kidneys to keep them in the body longer
What are adverse effects of penicillins?
Allergy/sensitivity (environmental exposure) CNS irritation/seizures (if an infection decreases permeability of BBB; doesn't normally cross BBB) GI irritation (diarrhea)
What causes penicillin resistance?
Production of B-lactamases (and transfer via plasmids)
Addition of (S aureus) or lack of PBP’s
Cell membrane not lysing after penicillin binds
Penicillins are inactive against organisms without cell walls
True or false: Penicillins are active against mycoplasma
False; they do not have cell walls
What super infections can occur if penicillins are misused?
Fungal; c diff
What are cephalosporins?
Beta lactams that are structurally similar to penicillins; they are semi-synthetic
Usually NOT first line agents
Describe the generations of cephalosporins
They have increasing gram negative activity with each generation
True or false: Pts with penicillin allergy can use cephalosporins
Meh
2-5% cross-sensitivity
If a pt has a severe penicillin allergy, cephalosporins are absolutely contraindicated
How are cephalosporins administered?
Cephalosporins have poor oral bioavailability; most are given pareneteral
What are 1st generation cephalosporins effective against?
Streptococci
S Aureus
Used in surgical prophylaxis
What are 2nd generation cephalosporins effective against?
E coli
Klebsiella proteus
H influenzae
Moraxella catarrhalis
What are 3rd generation cephalosporins effective against?
Enterobacteriacae P aeruginosa Serratia Nisseria gonorrhea Pseudomonas
Lack gram + activity!
What are 4th generation cephalosporins effective against?
Enterobacteriacae P aeruginosa Serratia Nisseria gonorrhea Pseudomonas
Lack gram + activity!
What are 5th generation cephalosporins effective against?
MRSA
Enterobacter
Streptococci
Enterococcus
Not yet approved in US
Name the oral cephalosporins
1st generation Cephalexin, Cephradine, Cefadroxil
(Lex is Rad, he Rox)
2nd generation Cefuroxime, Cefprozil
(He rox bc he’s a pro)
3rd generation Cefpodoxime, Cefibuten, Cefditoren, Cefixime
(He lives in a pod but he had to fib about what was toren)
4th generation: None
5th: None
What are adverse effects of cephalosporins?
cross-reactivity with penicillins (allergic/sensitivity)
Nephrotoxicity!
Bleeding disorders (Ring interferes with vitamin K, can cause bleeding)
Disulfuram reactions - no alcohol
Which cephalosporins have highest bleeding risk?
Cefmetazole
Cefoperazone
Went to the Met in Paris and started bleeding
What are carbapenems?
Broadest spectrum beta lactams
They are beta-lactamase resistant!
What do carbapenems work against?
Gram +, Gram -, anaerobes, and pseudomonas aeruginosa (Dorapenem, not Ertapenem)
Do carbapenems work against pseudomonas aeruginosa?
Yes
Dorapenem does
Ertapenem does not
Which carbapenem is dangerous for the kidneys?
Imipenem; it is metabolized into nephrotoxic compound in the renal tubule by dehydropeptidase
Compounded with cilastatin to inhibit the enzyme
What is imipenem compounded with? Why?
Cilastatin; it inhibits dehydropeptidase to prevent metabolism into nephrotoxic compound
How are carbapenems administered?
IV
What are the carbapenems? Name them
Imipenem
Meropenem
Ertapenem
Dorapenem
What are the indications for carbapenems?
Mixed aerobic and anaerobic intra-abdominal infections (people of Panem are hungry! get infections in their tummies)
Multi-drug resistant organisms; nosocomial infections (imipenem and meropenem)
Community acquired infections (ertapenem)
Abdominal and complicated UTI’s (Dorapenem)
Which carbapenem is useful in nosocomial infections?
Imipenem and Meropenem
Which carbapenem is useful in community acquired infections?
Ertapenem
Effie goes out into the community
Which carbapenem is useful in abdominal infections and complicated UTI’s?
Dorapenem
UTI’s are not aDORable
What adverse effects occur with carbapenems?
Sensitivity with other B-lactams (low-5%)
Seizures (Imipenem)
Anemia, thrombocytopenia, altered bleeding time (tests ONLY, doesn’t actually cause bleeding)
Which carbapenem is associated with seizures?
Imipenem
IMI - Intracranial muscle itchiness (seizures idk)
What are monobactams?
Aztreonam
What are monobactams effective against?
Aztreoname is effective against gram -, p aeruginosa, H influenzae, and gonococci
NOT GRAM +!
What are monobactams used for?
Multi-drug resistant strains
How are monobactams administered?
Aztreonam is given IV or IM
What are side effects of monobactams?
Nausea Vomiting Diarrhea Seizures Bone marrow suppression
Which agent has bone marrow suppression?
Aztreonam (monobactam)
Can monobactams be used in penicillin allergy?
Yes - no cross sensitivity with Aztreonam and penicillins
