Pharm - inhibitors of nucleic acid synthesis

Question 0

Sulfonamides inhibit ………………

Answer 0

Sulfonamides inhibit Dihydropteroate synthase. The initiating enzyme in bacterial folate synthesis.

Question 1

We divide this group of drugs into two subgroups. Name the two subgroups?

Answer 1

1 Drugs working on folate

2 Drugs working on enzymes associated with transcripition of replication.

Question 2

Trimethoprim and pyrimethiamine inhibit ………….

Answer 2

Trimethoprim and pyrimethiamine inhibit Dihydrofolate Reductase - an enzyme that is also found in humans, thereby producing anti-cancer drug-like side effects.

Question 3

Sulfonamides pharmacokinetics?

Answer 3

1 Hepatically acetylated(rendering the metabolite less soluble)
2 renally excreted metabolites cause crystalluria
3 high protein binding(kernicterus)

Question 4

“-floxacins” moa?

Answer 4

bactericidal and interfere with DNA synthesis by inhibiting topoisomerase II and IV.

-All “-floxacins” are quinolones.

Question 5

Sulfonamides origin?

Answer 5

structural analogues of PABA. What is PABA?

Question 6

Sulfonamides moa?

Answer 6

prevents synthesis of dihydrofolic acid, which is essential in producing THF - a cofactor in nucleic acid synthesis

Question 7

sulfonamides absorption and distribution?

Answer 7

well absorbed from GI, enters CNS

Question 8

sulfonamides target organisms?

Answer 8

• most gram negs + some gram pos.
• UTI
• Toxoplasmosis
• recurrent otitis media

Question 9

sulfamethoxazole + trimethoprim =

Answer 9

synergy(Bactrim/Fansidar)

Question 10

sulfonamides used in treating ulcerative colitis?

Answer 10

azaine and azulfidine

Question 11

sulfonamides adverse effects?

Answer 11

• hypersensitivity
• Steven-Johnson syndrome
• Kernicterus in neonates(bilirubin displacement from albumin)

Question 12

Rifampin co to jest?

Answer 12

RNA inhibitor

Question 13

Rifampin moa?

Answer 13

binds DNA dependent RNA polymerase @ beta-subunit

Question 14

Rifampin distribution?

Answer 14

Widely distributed, including CNS

Question 15

Rifampin target organisms?

Answer 15

gram pos, Neisseria spp., mycobacteria

Question 16

Rifampin adverse effects?

Answer 16

induces liver enzymes - increased metabolism of anticoagulants, contraceptives ++

Question 17

Nitrofurantoin moa and area of use?

Answer 17

• bacterial DNA damage by unknown mechanism

- used solely as urinary tract antiseptic against E. coli

Question 18

Fluoroquinolones generally have the suffix….?

Answer 18

-floxacin

Question 19

Fluoroquinolones moa?

Answer 19

• inhibit DNA gyrase(topoisomerase II) in gram negs.

- inhibit topoisomerase IV in gram positives.

Question 20

Fluoroquinolones area of use?

Answer 20

• urinary tract antiseptic( N. gonorrhoeae + MRSA)

- mycoplasma, legionella, chlamydia

Question 21

Polymyxins moa?

Answer 21

cationic basic polypeptide that disrupt bacterial cell membrane in gram negs

Question 22

Polymyxins adverse effects?

Answer 22

substantiel nephro and neurotoxicity

Question 23

Polymyxins areas of use?

Answer 23

• eye/ear drops

- topical administration

Question 24

Metronidazole target organisms?

Answer 24

anaerobes + anaerobe protozoal parasites

Question 25

Metronidazole moa?

Answer 25

unknown. possibly metabolite interferes with electron transport system and DNA synthesis

Question 26

Metronidazole contraindications?

Answer 26

pregnant in first trimester

Question 27

Daptomycin target organisms?

Answer 27

MRSA and VRE

Question 28

Daptomycin adverse effects?

Answer 28

may cause myopathy

Question 29

Linezolid target organisms?

Answer 29

MRSA and VRE

Question 30

Synercide target organisms?

Answer 30

Multdrug resistent bugs

Question 31

Synercide is composed of ………

Answer 31

2x streptogranins

Question 32

Synercide adverse effects?

Answer 32

decreased CYP 3A4 activity = increased potency in other drugs

Question 33

Which enzymes are inhibited by Sulfonamides and trimethoprim?

Answer 33

Sulfonamides - dihydrofolate synthase

Trimethoprim - dihydrofolate reductase

Question 34

Cross allergy between Sulfonamides and Thiazides?

Answer 34

No

Question 35

Sulfonamides adverse effect if administered during pregnancy?

Answer 35

Basal ganglia dysfunction due to spent folate