endocarditis

Question 1

penicillins name

Answer 1

benpen

phenoxymethylpen

Question 2

penicillin indications

Answer 2

strep, includign tonsillitis, pneumonia, endocarditis and skin and soft tissue infections

Question 3

penicillins MOA

Answer 3

• Benpen and phenoxy = narrow spec with some activity against gram +ve and gram -ve but only cocci

Question 4

MOA penicillins

Answer 4

inhibit enzymes needed for peptidogylcan cross linking in cell walls. = weak walls = no osmotic gradient maintained. –> cell swells, lysis and death
- contain b lactam ring = bactericidal. side chains modified to make semi synthetic penicillins.

Question 5

SE penicllins

Answer 5

• allergy, skin rash 7-10 days post exposure or 1-2 days after repeat exposure - delayed IgG reaction.

less common = IgE reaction immediately.

• v high dose = neuro toxicity or accumualtion due to renal imapirment

Question 6

warnings - penicillin

Answer 6

• dose reduction in renal impairment
• hx penicillin allergy = CI
• cross reactivity with simialr structure abx = cephalosporins etc

Question 7

penicillin interactions

Answer 7

• reduce renal excretion of methotrexate

Question 8

how can you give benpen

Answer 8

IV(slow injection or infusion) or IM - hydrolysis by gastric acid = no GI absoprtion orally. usual dose 1.2g

Question 9

how can you take phenoxymethylpen

Answer 9

• tablets or other routes.

Question 10

half life of benpen and phenoxy

Answer 10

30-60mins so must give 4-6hrly

Question 11

name penicillins that are penicllinase resistant

Answer 11

flucloxacillin

Question 12

indications for fluclox

Answer 12

• skin and soft tissue infections
• osteomyelitis and septic arthritis
• ither infections including endocarditis

Question 13

specretum of activity of penicillinase resistant pens

Answer 13

• narrow spec agains gram +Ve staph

Question 14

MOA penicillinase resistant pens

Answer 14

• as for penicllins; prevent cross linking and lead to lysis.
• additional in fluclox; side chain = acyl proteing b lactam from b lactamases

Question 15

what bacteria are resitant to fluclox

Answer 15

MRSA

Question 16

SE penicillianse resistant pens

Answer 16

• Minor GI upset
• allergy as for pens.
• liver toxicity - cholestastis or hepatitis

Question 17

when to use fluclox carefully

Answer 17

• renal failure; dose reduce

- hepatic impairment reduce dose

Question 18

CI to fluclox

Answer 18

• hx of pen allergy.

- prior fluclox related hepatotoxicity

Question 19

interactions of fluclox

Answer 19

methotrexate increased toxicity

Question 20

fluclox half life

Answer 20

45-60mins

Question 21

vancomycin Indications

Answer 21

• treat grma +Ve infection e.g. endocarditis, where severe ifnection +/- penicllin resistance or allergy
• treatment of c diff where metro is unsuccesful/CI

Question 22

Vanc spectrum of activity

Answer 22

narrow spec, gram +Ve - staph, strepp, c diff

• vancomycin resistant enterocci = increasing concern. no activity in gram -ve

Question 23

Vanc MOA

Answer 23

• inhibits cross linking of peptidoglycans and inhibit synthesis of cell wall of gram +Ve.

Question 24

SE vanc

Answer 24

• thrombophlebiris at infusion site
• rapid infusion = red man syndrome; generalised erythema +/- bronchospasm and hypotension
• allergy

IV = nephrotoxic inc RF and interstitial nephritis

• otoxic
• neutropenia and thrombocytopenia

Question 25

vanc dose reduction in which patients

Answer 25

• renal impairment and elderly

Question 26

for systemic ifnection how do you give vanc

Answer 26

IV

Question 27

for c diff how to give vanc

Answer 27

orall 125mg 6hrly 10-14 days

Question 28

how to monitor IV vanc

Answer 28

• pre dose palsma conc

- adjust dose to keep conc above 10mg/L and below 15mg/L