UWorld Pharmacology - Derm drugs

Question 1

Tx of dermatophytosis. MOA

Answer 1

Terbinafine.

MOA: inhibits squalene epoxidase, which inhibits fungal cell membrane formation by inhibiting ergosterol synthesis

Question 2

Antifungal that has MOA of binding to ergosterol, creating pores in the fungal membrane.

Answer 2

amphotericin B and nystatin

Question 3

Drug class that blocks Beta-1,3-D-glucan, blocking fungal cell wall synthesis. Especially in aspergillus and candida.

Answer 3

the echinocandins - caspofungin, anidulafungin, micafungin

Question 4

Drug that binds to polymerized microtubules and disrupts fungal mitotic spindle, preventing fungal mitosis.

Answer 4

Griseofulvin

Question 5

Antimetabolite antifungal that is transformed into 5-Fluorouracil in fungal cell. Inhibits fungal protein sythesis by replacing uracil with 5-Fluorouracil in fungal mRNA. Used for systemic fungal infections (crypto).

Answer 5

Flucytosine.

Question 6

Tx for androgenetic alopecia (polygenic inheritance).

Answer 6

5-alpha-reductase inhibitors (finasteride) to inhibit testosterone conversion to dihydrotestosterone

Question 7

Name viral dependent nucleosides.

MOA

Answer 7

Acyclovir, valacyclovir, famcyclovir - all HSV, VZV
Gancyclovir (CMV)

MOA - complete inhibition of viral DNA polymerase

Question 8

Name nucleoside monophosphate. how are they different from viral dependent nucleosides?

Answer 8

They are nucelotides, so they only require cellular kinases for activation. Cidofovir and Tenofovir.

Question 9

An eczematous dermatitis patient presents with atrophy of dermis and loss of dermal collagen, drying, cracking, and or tightening of skin. Telangiectasia,also possible.

What is the person being treated with?

Answer 9

This is dermal atrophy due to topical corticosteroid use.

Question 10

What drug inhibits NFAT (nuclear factor of activated T cells) from entering nucleus and modulating transcription activity?

Answer 10

cyclosporin

Question 11

What antiviral is a recombinant form of human TNF that binds to TNF-alpha.

Answer 11

Etanercept

Question 12

Antifolate metabolite that reversibly binds to DHFR, resulting in inhibition of purine and thymidylic acid syntehsis.

Answer 12

MTX

Question 13

Antiviral class that inhibits influenza neuraminidase, decreasing progeny release from virus.

Answer 13

Neuraminidase inhibitors - oseltamivir, zanamivir

Question 14

Antiviral drug class that inhibits uncoating of virus.

Answer 14

Amantadine - used for Parkinson

Question 15

Abacavir, tenofovir, zidovudine - MOA and use

Answer 15

HIV antiviral therapy - NRTI. Impairs viral RNA replication.

Question 16

Antifungal class/drugs that bind to ergosterol molecules in fugnal cell mamrbeans creating pores and causing cell lysis.

Answer 16

polyenes -amphotericin B, nystatin

Question 17

Antifungal class/drugs that inhibits syntehsis of ergosterol

Answer 17

triazoles - ketoconazole, fluconazole, itraconazole, voriconazole

Question 18

Antifungal class/drugs that inhibit synthesis of glucan, a component of the fungal cell wall.

Answer 18

Echinocandis - caspofungin, micafungin

Question 19

Antifungal class/drugs that conver 5-fluorouracil within fungal cell and interfer with fungal RNA and protein syntehsis

Answer 19

pyrimadines- flucytosine

Question 20

name the three beta-lactamase inhibitors

Answer 20

clavulanic acid, sulbactam, tazobactam (CAST)

Question 21

What class has MOA that interferes with DNA gyrase (topoisomerase 2)?

Answer 21

Fluoroquinolones

Question 22

What drug combination is effectinve against most gram negative anaerobic rods (psudomonas and bacteroides)? Why?

Answer 22

Pipercillin-tazobactam

Add tazobactam because it protect the antibiotic form dstruction by beta-lactamase (penicillinase).

Question 23

tx of N. gono/Chlamydia

Answer 23

Azithromycin (inhibit protein synthesis by binding to 23S rRNA of 50s ribsosome) + Ceftriaxone (beta-lactam drug that inhibits cell wall synthesis).

Question 24

The two methods of gene INH resistance

Answer 24

1. decreased bacterial expression of catalase-peroxidase enzymes that are required for INH activation once drug enters bacterial cell.
2. Modification of protein target binding site for INH

Question 25

When can you use INH monotherapy?

Answer 25

positive PPD with negative chase XR - no evidence of clinical disease.

Question 26

Anaerobic above v. below diaphragm

Answer 26

Above - clindamycin (clean gym) | Below - metronidazole

Question 27

A 19 year old male presents with an ulcer on his penis. It is indurated, painless, and no surrounding erythema or inguinal LAD. College student. What is this and what drug?

Answer 27

Treponema pallidum Tx with Penicillin - bc they are gram negative with peptidoglycan cell wall.

Question 28

MOA of penicillins

Answer 28

They are structurally similar to D-ala-D-ala, inhibiting transpeptidase by binding COVALENTLY to the acitve site. Results in failed synthesis of bacterial peptidoglycan cell wall.

Question 29

How is penicillin and vancomycin MOA differen?

Answer 29

Vanc binds DIRECTLY to D-ala-D-ala. | Penicillins bind covalently.

Question 30

What class of antibiotics compete with Para-aminobenzoic acid for incirportaitn into folic acid. Whatcalss blocks another step in folic acid synthesis by inhibiting dihydrofolate reductase?

Answer 30

sulfonamides trimethoprim

Question 31

What is the most potent diuretic, used especially in acute decompensated HF. Where is its MOA?

Answer 31

Loops (furosemide) act on Thick ascending loop. Na/K/2Cl.

Question 32

What diuretic acts on the Dct?

Answer 32

thiazides - Cl/Na reabs

Question 33

What diuretics act on CT?

Answer 33

K-sparing - spironolactine and Na-CB (amelioride)

Question 34

A person with high plasma renin levels and volume depletion or HF is started on ACEinhibitor (lisinopril). What is a likely side effect.

Answer 34

First dose Hypotension.

Question 35

CYP inducers do what to a paerson on warfarin? | CYP inhibitors do what to a person on warfarin?

Answer 35

- inducers will decrease effect of warfarin, increasing its metabolism. (CHRONIC ALCOHOLICS, ST. johns wart, PHENytoin, PHENobarbitol, NEvirapine, Rifampin, GRiseofulvin, CARBamazepine). - inhibitors will potentiate warfarin by blocking its metabolism, increasing bleeding risk. (Acute Alcohol Abuse, Ritonavir, Amiodarone, Cimetidine, Ketoconazole (azoles), Sulfonamides, INh, Grapefruit Juices, Quinidine, MAcrolides (except azithromycin).

Question 36

SE of antipsychotic - akisthisia

Answer 36

inability to sit still

Question 37

SE of antipsychotic - NMS

Answer 37

fever, rigidity, mental status changes, autonomic instabiltiy

Question 38

SE of antipsychotic - tardive dyskinesia

Answer 38

lip smacking, choreathetoid movements - involuntary mvmts after chronic use

Question 39

What is indicated for treatment of bradycardia bc it decreases vagal influence on SA and AV nodes. When is this contraindicated?

Answer 39

ATropine. CI if the person has glaucoma bc the increased intraocular pressure may precipitate close angle galucoma (severe unilateral eye pain and visual disturbances).

Question 40

When would a SERM (i.e. tamoxifen) be appropriate to use in a male?

Answer 40

If he is getting tx with androgen-deprivation therapy (ADT) for prostate cancer.

Question 41

Role of desmopressin in tx Hemophilia A or vWF disease

Answer 41

Incrases factor 8 and endothelial secretion of vWF.

Question 42

``` What do opioids do to: histamine release gut motility pariteal cell acid secretion hepatocytes skeletal muscle pancreas ```

Answer 42

``` increase decrease decerase no effect no effect no effect ```

Question 43

Digoxin, B-blockers, and CCB can all cause what change on ECG?

Answer 43

prolonged PR interval (First degree block - PR >200 msec).

Question 44

Diuretic that can cause gout.

Answer 44

thiazide