Clindamycin

Question 1

Clindamycin is a

Answer 1

lincosamide antibiotic; chlorine-substituted derivative of lincomycin

Question 2

Clindamycin is bactericidal/bacteriostatic

Answer 2

bacteriostatic

Question 3

Clindamycin MOA

Answer 3

inhibits protein synthesis by binding reversibly to 50S ribosomal subunits of susceptible bacteria
inhibits peptide formation and interferes with translocations step

binds near site where macrolides bind

Question 4

Clindamycin spectrum coverage

Answer 4

dark purple: prevotella

light purple: streptococcus, s. pneumoniae, viridans, MSSA, MRSA

dark red: fusobacterium

light red: bacteroides, clostridium

Other: pneumocystic jirovecii, protozoa

Question 5

Clindamycin resistance mechanisms

Answer 5

mutation of bacterial ribosomal RNA

alterations in 50S ribosomal proteins at receptor site

enzymatic inactivation

modification of 23S ribosomal unit of 50S receptor by methylation of adenine (erm)

inducible resistance occurs during therapy

Question 6

Macrolide and Lincosamide resistance

Answer 6

methylation of the ribosomal target which leads to cross-resistance to macrolides, lincosamides, and streptogramin B

MLSB phenotype which can be constitutive or inducible

Question 7

Macrolide and Lincosamide resistance is mediated by

Answer 7

plasmids

Question 8

Efflux by ERY

Answer 8

msrA (low level)

Question 9

ribosome alteration (ERY, CLI)

Answer 9

Erm (high level)

Question 10

Drug inactivation (CLI)

Answer 10

inuA (rare)

Question 11

D-test positive is when

Answer 11

erythromycin causes clindamycin ring to look like a D

Question 12

msrA

ERY:
CLI:

Answer 12

E: R
C: S

Question 13

erm

ERY:
CLI:

Answer 13

E: R
C: S inducible

Question 14

erm

ERY:
CLI:

Answer 14

E: R
C: R constitutive

Question 15

both negative

ERY:
CLI:

Answer 15

E: S
C: S

Question 16

Clindamycin absorption

Answer 16

nearly completely absorbed after oral administrayion

Question 17

Clindamycin can be given

Answer 17

IV/IM or PO

Question 18

Clindamycin tissue penetration

Answer 18

readily distributed into most fluids and tissues EXCEPT CSF

penetrates well into abbesses and phagocytic cells
high levels in bones
crosses placenta

Question 19

Clindamycin elimination

Answer 19

metabolized by liver so accumulation may occur in severe hepatic failure, may require dose adjustment

Question 20

Antimicrobial activity persists in feces for

Answer 20

> 5 days after IV is stopped

Question 21

Clindamycin 1/2 life

Answer 21

2.5 hours, short

Question 22

Clindamycin should/should not be renally adjusted

Answer 22

should not

Question 23

In severe hepatic disease, monitor

Answer 23

liver enzymes during therapy

Question 24

Clindamycin indications

Answer 24

skin and soft tissue infections caused by strep and staph

• CA MRSA
• inhibits bacterial toxin synthesis (role in necrotizing infections)

respiratory tract infections

other anaerobic infections

• female genital tract
• prophylaxis of endocarditis in patients with valvular disease undergoing certain dental procedures

with primaquine used as alternative for pneumocystis jirovecci pneumonia

with pyrimethamine for AIDS related toxoplasma encephalitis

topical clindamycin for acne and bacterial vaginosis

anaerobic infections (tooth abscesses)

surgical prophylaxis

antibiotic prophylaxis for GBS in penicillin allergic

Question 25

Clindamycin adverse effects

Answer 25

GI: nausea, vomiting, diarrhea, mostly with PO skin rash impaired liver function neutropenia C. diff infections may potentiate effect of neuromuscular blockers if administer concurrently

Question 26

Clindamycin drug interactions

Answer 26

may block neuromuscular transmission and enhance the action of other blocking agents

Question 27

Clindamycin use during pregnancy

Answer 27

inconclusive or inadequate evidence in pregnant, WHO recommends avoiding while breast feeding