Sulfonamides, Trimet, Quinolones

Question 0

Sulfacetamide

Answer 0

Use: conjunctivitis , corneal ulcer, and other superficial ocular infections
MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: irritation, stinging or burning

Question 1

Silver sulfadiazine

Answer 1

Use: burns
MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: irritation, stinging or burning

Question 2

Triple sulfa

Answer 2

Use: for vaginitis caused by H. Vaginalis
MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: irritation, stinging or burning

Question 3

Sulfisoxazole

Answer 3

Use: uncomplicated urinary tract infections
Usually used with phenazopyridine
MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: hypersensitivity -skin rash, fever, urticaria. Cross sensitivity with other sulfa drugs. N/v/d, crystalluria, allergic nephritis, hematopoietic disturbances, hemolytic anemia in pts with g6pd deficiency, kern icterus in newborns by displacement of serum albumin.

Question 4

Sulfamethoxazole

Answer 4

Use: uncomplicated urinary tract infections
Usually used with trimethoprim

MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: hypersensitivity -skin rash, fever, urticaria. Cross sensitivity with other sulfa drugs. N/v/d, crystalluria, allergic nephritis, hematopoietic disturbances, hemolytic anemia in pts with g6pd deficiency, kern icterus in newborns by displacement of serum albumin.

Question 5

Sulfadoxine

Answer 5

Use: malaria
Usually used with pyramethamine

Very long lasting

MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: hypersensitivity -skin rash, fever, urticaria. Cross sensitivity with other sulfa drugs. N/v/d, crystalluria, allergic nephritis, hematopoietic disturbances, hemolytic anemia in pts with g6pd deficiency, kern icterus in newborns by displacement of serum albumin.

Question 6

Sulfadiazine

Answer 6

Use: used to treat toxoplasmosis
Usually used with pyramethamine

MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: hypersensitivity -skin rash, fever, urticaria. Cross sensitivity with other sulfa drugs. N/v/d, crystalluria, allergic nephritis, hematopoietic disturbances, hemolytic anemia in pts with g6pd deficiency, kern icterus in newborns by displacement of serum albumin.

Question 7

Dapsone

Answer 7

Use: to treat leprosy

MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: hypersensitivity -skin rash, fever, urticaria. Cross sensitivity with other sulfa drugs. N/v/d, crystalluria, allergic nephritis, hematopoietic disturbances, hemolytic anemia in pts with g6pd deficiency, kern icterus in newborns by displacement of serum albumin.

Question 8

Sulfasalazine

Answer 8

Use: to treat inflammatory bowel disorder

Not absorbed- active ingredient is 5-aminosalicylic acid

MOA: competitively inhibit the conversion of PABA to folic acid mediated by the enzyme dihydropteroate synthase which ultimately inhibits DNA synthesis

Side effects: hypersensitivity -skin rash, fever, urticaria. Cross sensitivity with other sulfa drugs. N/v/d, crystalluria, allergic nephritis, hematopoietic disturbances, hemolytic anemia in pts with g6pd deficiency, kern icterus in newborns by displacement of serum albumin.

Question 9

Trimethoprim

Answer 9

MOA: inhibits dihydrofolate reductase of bacteria 10,000 times more efficiently than mammalian cells . Bacteriostatic.

Use: used alone for acute UTIs
Used in combo with sulfamethoxazole for other infections

Adverse effects: similar to sulfa drugs plus rare hematopoietic disturbances ( megalomaniac anemia, leukopenia) use folinic acid to prevent hematologic toxicity.

Question 10

Uses for trimethoprim and sulfamethoxazole

Answer 10

Pneumonia - due to pneumocystis carinii (oral and IV)
GI infections - shigella enteritis
Systemic infections caused by norcardia and salmonella
UTIs and respiratory infections caused by h. Influenza or streptococcus pneumonae
Listeria meningitis

Question 11

Quinolones (fluoroquinolones)

Answer 11

Synthetic fluoridated antimicrobial agents

Moa: block DNA synthesis by in hi biting topoisomerase II ( DNA gyrate) and topoisomerase IV . This prevents unwinding of supercooled DNA that is required for normal transcription and duplication . IV deals with the separation of replicated chromosomal DNA.

Question 12

Ciprofloxacin

Answer 12

Gram - and some activity against gram + , h. Influenzae

Question 13

Levofloxacin , gemifloxacin, moxifloxican

Answer 13

Improved activity against gram + particularly s. Pneumoniae

Question 14

Quinolone Resistance occurs due to what.

Answer 14

Microbial modification of DNA gyrase or topoisomerase IV structure.

Alteration of members never me ability into the bacterial cell

Question 15

Sulfonamides gain resistance how

Answer 15

Microbial overproduction of PABA

Structural changes that occur in bacterial dihydropteroate synthase

Decreased permeability

Question 16

Use of Ciprofloxacin

Answer 16

Topical : eye- conjunctivitis, corneal ulcer, and other superficial ocular infections

Oral: resistant uti, infectious diarrhea( shigella, salmonella, e. Coli, campylobacter) typhoid fever, single dose to treat gonorrhea, pseudomonas , anthrax

Question 17

Clinical use of levofloxacin

Answer 17

Oral: resistant uti, infectious diarrhea( shigella, salmonella, e. Coli, campylobacter) typhoid fever, single dose to treat gonorrhea, pseudomonas , anthrax , osteomyelitis and skin structure Infections

Respiratory tract infections including cap, reserved for pts with comorbidity or risk factors

Question 18

Clinical uses of gemifloxacin

Answer 18

Oral: osteomyelitis and skin structure Infections

Respiratory tract infections including cap, reserved for pts with comorbidity or risk factors

Question 19

Moxifloxican clinical uses

Answer 19

Oral: osteomyelitis and skin structure Infections and single dose for treatment of gonorrhea

Respiratory tract infections including cap, reserved for pts with comorbidity or risk factors

Question 20

Sides effects of Quinolones

Answer 20

Topical - irritation, stinging or burning
Systemic effects
- n/v/d
-‘photosensitivity, CNS disturbances : dizzy, confusion, hallucinations)
- damage growing cartilage : no children or preggers
- prolong qt interval : don’t use in pts taking antiarrhythemiad and other drugs that prolong that qt ( erythromycin, tricyclic antidepressants)