Drugs to know

Question 1

What do tetracyclines do?

Answer 1

Bind to small subunit of ribosome Interfere with tRNA binding (block attachment of tRNA to ribosome) meds = doxycycline and minocycline

Question 2

What do aminoglycosides do?

Answer 2

Bind to small subunit of ribosome Bend mRNA and cause misread of codon; blocks initiation and ribosome formation Drug ex: tobramycin and gentamicin

Question 3

What do macrolides do?

Answer 3

Bind to large subunit of ribosome Block translocation Drugs: Clarithromycin, erythromycin and azithromycin

Question 4

What do lincosamides do?

Answer 4

Bind to large subunit of ribosome Blocks peptide bond formation and translocation Drugs: clindamycin and lincomycin

Question 5

What do Oxazolidinones do?

Answer 5

Bind large subunit of ribosome Interferes with initiation and ribosome formation Drugs: linezoild

Question 6

What do amphenicols do?

Answer 6

Bind large subunit of ribosome Block peptide bond formation drug: chloramphenicol

Question 7

What is job of B-lactam antibiotics?

Answer 7

They inhibit (block) transpeptidase enzymes so crosslinking cant occur

Question 8

What are some examples of B-lactams ?

Answer 8

1. penicillins - Amox, Penicillin V 2. Cephalosporins - Cephalexin 3. Monobactams 4. Carbapenems

Question 9

How does the inhibition of Transpeptidase by penicillin work?

Answer 9

The pocket of the bacteria that needs to be linked together by the side groups of penicillin such that hydrolysis by water cant happen. This makes transpeptidase being irreversibly inhibited, leading to no crosslinking to cell death

Question 10

What does a bacteria do to have drug resistance?

Answer 10

The bacteria produces production of a B-lactamase enzyme which chemically degrades (destroys) the B-lactam drug

Question 11

What are ways we have overcome the bacterial drug resistance ?

Answer 11

We targeted the B-lactamase enzyme Augmentin is a combo of B-lactam antibiotic and clavulanic acid – The clavulanic acids acts as an irreversible inhibitor of B-lactamase to prevent the cleavage and inactivation of the amoxicillin

Question 12

What are Antimetabolites?

Answer 12

They are compounds that resemble and interfere with something required for metabolism

Question 13

What are some examples of antimetabolites?

Answer 13

5-fluorouracil and capecitabine which resemble dUMP and inhibit thymidylate synthase 6-mercaptopurine, an analog of hypoxanthine (leads to xanthine) Allopurinol - a substrate and then inhibitor xanthine oxidase

Question 14

What are antifolates?

Answer 14

These resemble a portion of tetrahydrofolate

Question 15

What are some examples of antifolates?

Answer 15

Aminopterin, methotrexate, and trimethoprim which inhibit dihydrofloate reductase Sulfa antibiotics which block the synthesis of folic acid

Question 16

How does allopurinol and febuxostat treat gout?

Answer 16

Remember Xanthine oxidase carries out the last two steps in the formation of uric acid 1. Allopurinol and febuxostat inhibit xanthine oxidase 2. if you inhibit xanthine oxidase it will decrease the amount of uric acid in the system

Question 17

What specifically does allopurinol do to xanthine oxidase?

Answer 17

It makes oxypurinol (adds an oxygen) which inhibits the use of the enzyme

Question 18

How does 5-Fluorouracil and capecitabine (prodrug) inhibit dTMP synthesis?

Answer 18

They act as suicide inhibitors and covalently bind to and irreversibly inhibits thymidylatye synthase **adds a F which can not be taken off

Question 19

How does Aminopterin Methotrexate and Trimethoprim stop dTMP synthesis?

Answer 19

It inhibits dihydrofolate reducatse **remeber this creates the 5, 10 methylene thing that is used in order to convert dUMP to dTMP

Question 20

How does bactrim (trimethoprim + sulfamethoxazole) stop dTMP synthesis?

Answer 20

It inhibits both folic acid synthesis and dihydrofolate reductase

Question 21

What two enzymes are used in the salvaging nucleosides?

Answer 21

Deoxycytidine kinase Thymidine kinase **these are very specific and add the first phosphate to recover the nucleoside **they only work on cytidosine and thyosine

Question 22

How does Acyclovir and Valacyclovir work as antivirals?

Answer 22

They resemble guanosine which means they act like nucleoside reverse transcriptase inhibitors (NRTIs) *it gets phosphorylated and activated then gets incorporated into viral DNA which stops it ably to replicate and it dies **Important to know this only slows down infection and eases symptoms, you body still needs to deal with it