Week 10 - Metronidazole, Tinidazole, Topical Agents

Question 1

Metronidazole (Flagyl): activity

Answer 1

Gram (+) AND gram (-) anaerobes

C. diff, bacteroides fragilis, h. pylori, t. vaginalis, gardnerella vaginalis

Question 2

Metronidazole (Flagyl): indications

Answer 2

C. diff infection, bacterial vaginosis, h. pylori eradication, trichomoniasis, PID

Use metronidazole after PO vancomycin

Treatments both parasiti and bacterial infections

Question 3

Metronidazole (Flagyl): MOA

Answer 3

Diffuses into organism and interacts with DNA to cause loss of helical DNA structure and strand breakage –> inhibition of protein synthesis and cell death

Question 4

Metronidazole (Flagyl): ADR

Answer 4

Nausea, abdominal pain, anorexia, dizziness, HA, metallic taste, dry mouth, dark urine

Rare: agranulocytosis, CNS effects

Question 5

Metronidazole (Flagyl): caution and contraindications

Answer 5

• BLACK BOX: potentially carcinogenic
• Caution in renal and hepatic impairment
• Caution in patients with seizure disorder
• Avoid in first trimester of pregnancy

Question 6

Tinidazole: activity

Answer 6

Bacteroides fragilis, h. pylor, t. vaginalis, gardnerella vaginalis

NO c. diff

Question 7

Tinidazole: indications

Answer 7

Bacterial vaginosis, h. pylori eradication (off label), trichomoniasis, urethritis

Question 8

Tinidazole: MOA

Answer 8

After diffusing into organism, thought to cause cytotoxicity by damaging DNA and preventing additional DNA synthesis

Question 9

Tinidazole: ADR

Answer 9

Fatigue, metallic taste, nausea, anorexia

Rare: seizures, peripheral neuropathy, super infection

Question 10

Tinidazole: caution and contraindications

Answer 10

• BLACK BOX: potentially carcinogenic
• Caution in hepatic impairment
• Avoid in pregnancy and lactation
• Approved in children >3 years

Question 11

Causes of impetigo

Answer 11

S. aureus, s. pyogenes

Question 12

Topical agents used to treat impetigo

Answer 12

• Up to 5 lesions = mupirocin (Bactroban)

Question 13

Topical agents used to treat oral candidiasis

Answer 13

Topical nystatin or clotrimazole

Question 14

Topical agents used to treat vulvovaginal yeast infections

Answer 14

Miconazole or clotrimazole

Or one time dose of fluconazole

Question 15

Topical agents used to treat tinea pedis (athlete’s foot) and tinea corporis (jock itch)

Answer 15

Terbinafine, miconazole, ketoconazole, clotrimazole

NOT nystatin

Question 16

Topical agents used to treat herpes simplex (e.g. labialis)

Answer 16

Acyclovir, penciclovir, docosanol

Question 17

Why would the prescriber use double abx or triple abx therapy to treat impetigo?

Answer 17

Double: bacitracin + polymixin B

Triple: bacitracin + neomycin + polymixin B

Used when broader antibacterial coverage needed

Question 18

What should be prescribed if the patient has more than five lesions when associated w/ impetigo?

Answer 18

Oral abx or if no improvement with topicals after 2-3 days

• Cephalexin, amoxicillin/clavulanate, dicloxacillin

Question 19

Oral abx options used to treat MRSA (outpatient setting)

Answer 19

Clindamycin, TMP/SMZ, doxycycline