nurs329 quiz 1 - drugs that weaken cell wall pt. 1 (PENICILLIN)

Penicillin

(beta lactam) disrupt bacteria wall (not very toxic to liver = good) by osmosis (cause to explode + die)

how does penicillin weaken cell wall

inhibit transpep (what helps bacteria to grown), activate (disinhibit) autolysin (cause it to eat itself + go wild instead of slowly grow)

what is needeed for PCN to work

bind to target (PBP) on bacteria (to produce effects -> bactericidal = osmosis + explode)

penicillinase (beta-lactamase -> DIFF FROM BETA LACTAM RING)

(produced by bacteria trying to resist) destroys beta lactam ring

PCN bacteria resistance - gram (+) cell envelope

2 layers (cytoplasmic membrane, thick) but PCN can still penetrate (to PBP)

PCN bacteria resistance - gram (-) cell envelope

3 layers (cytoplasmic mem, thin wall, ADDITIONAL outer membrane), harder to penetrate (still possible)

NARROW penicillinase sensitive - PCN G

(narrow spectrum, preferred) gram +, some gram -

NARROW penicillinase sensitive - PCN G used for

prophylaxis of BE (bacteria endo, heart valave, congen heart), dental procedure, pneumonia, meningitis

how is PCN G NOT given

PO (not good in low pH), usually IM (K+, procain, benzathine, Na+)

NARROW penicillinase sensitive - K+ and Na+ PCN

short term (15 mins), IV (only ones that can)

NARROW penicillinase sensitive -Procaine + benzathine PCN

long term, IM only NO IV

PCN G - distribution

(distribute well) high penetrate in CSF, joint, eye WITH inflamm (other wise not very good penetrate)

what to consider w PCN G

check kidney (trough/peak in elder, renal disease, kids)

PCN G side effects

allergic rxn, pain at IM site, neurotoxic (w high blood lvls, seizure, check peak/trough), hyperkal w IV + PCN salts (in large doses)

what NOT to give w PCN

aminoglycosides (NO in same IV tube, PCN inactivate amino, BUT YES TG IN BODY)

PCN V

(same as PCN G) yes PO w meals

penicillinase-resistant PCN types

(still work even if penicillinase try to eat ring, NARROW, CELL DEATH) nafcillin, oxacillin, dicloxacillin

naficillin

IV only (Gi absorb erratic/incomplete)

oxacillin + dicloxacillin

IV, PO w meals (acid stable)

broad spectrum PCN - aminopenicillin types

ampicillin, amoxicillin (good for gram+/-)

ampicillin + amoxicillin

works on gram - (E. coli, H influenza, shigella)

extended spectrum PCN - antipseudomonal PCN

ticarcillin, piperacillin (need to combine w other med for strong results, works for long)

ticarcillin + piperacillin usually combine w

aminoglycoside (to increase kill ratio), beta lactamase inhibit (tazobactam to help w resistance)

ticarcillin + piperacillin are good against

largely resistant bacteria (Pseudomonas, enterobacter)

PCN allergy

(no relation w dose + intensity) prior exposure, AVOID cephalosporin (also bc has beta lactam ring)

PCN allergy - immediate

2-30 min

PCN allergy - accelerated

1-72 hrs

PCN allergy - late

days/wks

PCN allergy - anaphylaxis

(larynx) edema, broncho constrict, LOW BP

PCN allergy - treatment

(STOP DRUG, help airway) epi, IV/PO benadryl (skin test)