Antibiotics: Misc (Clindamycin, Metronidazole, Fidaxomicin, Rifaximin, Etc)

Question 1

Chloramphenicol

Answer 1

Agent rarely used due to AEs
-Fatal blood dyscrasias (aplastic anemia, pancytopenia)
-Gray syndrome (circulatory collapse, cyanosis, acidosis)

Chlor has a fatal BD Gray

Question 2

Clindamycin: Dosing/BBW/AE

Answer 2

CA-MRSA, anaerobes, G+

Dosing:
-PO: 150-450 mg Q6H
-IV: 600-900 mg Q8H
-No renal dose adj

BBW: C. diff

AE: NVDR, urticaria

Question 3

Clindamycin: Special Notes

Answer 3

-Induction test (D-test) should be performed on S. aureus that is susceptible to clindamycin but resistant to erythromycin
-A flattened zone between the disks (positive D-test) indicates inducible clindamycin resistance and clindamycin should not be used

Question 4

Metronidazole: BBW/AE/Notes

Answer 4

-Bacterial vaginosis, trichomoniasis

Dosing:
-PO/IV: 500-750 mg Q8-12h or 250-600 mg Q6-8h
-No renal dose adj
-IV:PO ratio is 1:1

BBW: possibly carcinogenic based on animal data

CI:
-Pregnancy (1st trimester)
-Use of alcohol or propylene glycol products during tx or within 3 days of d/c (disulfiram rxn)
-Use of disulfiram within the past 2 weeks

Warnings:
-Aseptic meningitis
-Encephalopathy
-Optic neuropathy
-CNS (seizure, peripheral neuropathy)

AE:
-Metallic taste
-Furry tongue

MET that MF PAPA in CODE 1

Question 5

Tinidazole: BBW/CI/AE

Answer 5

Dosing:
-2 g PO daily

BBW: possibly carcinogenic based on animal data

CI:
-Pregnancy (1st trimester)
-Use of alcohol or propylene glycol products during tx or within 3 days of d/c (disulfiram rxn)
-Breastfeeding

Warnings:
-CNS (seizure, peripheral neuropathy)

AE:
-Metallic taste
-Furry tongue

Same as metro + CI in BF basically

Question 6

Secnidazole: Dosing/Warnings

Answer 6

2 g SINGLE DOSE
-Sprinkle contents of 1 packet onto pudding/yogurt and eat within 30 min, do not chew granules

Warnings:
-Vulvovaginal candidiasis
-Possibly carcinogenic based on animal data

SEC (sex) in vulvo cancer

Question 7

Lefamulin (Xenleta): CI/W/AE

Answer 7

Dosing:
-PO: 600 mg Q12H
-IV: 150 mg Q12H

CI:
-CYP3A4 that prolong QT

W:
-Pregnancy (teratogenic)
-QTP

AE:
-ND, inj site rxn

LEFA QPC

Question 8

Fidamoxicin (Dificid): Dosing/W/AE

Answer 8

For C. diff

Dosing: 200 mg BID x10 days
-No renal dose adj

W:
-Not affected for systemic infections

AE: NV, abd pain, GI bleed, anemia

Question 9

Rifaximin (Xifaxan): AE/Notes

Answer 9

AE: GERD HA
-Peripheral edema
-Dizzy
-HA
-GI (nausea, abd pain)
-Rash, pruritus

Notes:
-Not effective for systemic infections
-Used off-label for C. diff (third or subsequent recurrence)

Question 10

Fosfomycin (Monural): Dosing/AE

Answer 10

Packet granules = 3 g per packet

Female, uncomplicated UTI
-Dosing: 3 g PO x1 (mixed in cold water)

AE: HA, diarrhea, nausea

Question 11

Nitrofurantoin (Macrobid): D/CI/W/AE

Answer 11

MacroBID: 100 mg PO BID x 5 days
-Macrodantin is QID x3-7d (QHS for ppx)

CI:
-Renal, CrCl < 60

W:
-Optic neuritis
-G6PD deficiency (hemolytic anemia)

AE:
-GI (take with food)
-Brown urine discoloration (harmless)

NITRO/MAC the OG FB is 60!

Question 12

Mupirocin Nasal Ointment

Answer 12

Used to eliminate staphylococci (MRSA) colonization of the nares

~500 mg in each nostril BID x 5 days

AE: HA, burning, localized irritation, rhinitis, pharyngitis