Sulfonamides and Potentiated Sulfonamides

Question 1

Are Sulfonamides bacteriostatic or bactericidal?

Answer 1

Bacteriostatic

Question 2

Sulfonamides are one of the first antimicrobials to be used on a widespread basis, which has caused bacteria to become what to them?

Answer 2

Many strains of bacteria have become resistant to them

Question 3

Sulfonamides are potentiated with what to potentiate their antibiotic effects & convert them from bacteriostatic to bactericidal?

Answer 3

Trimethoprim & Ormetoprim

Question 4

What is Sulfadimethoxine combined with and what drug is it found in?

Answer 4

Combined with Ormetoprim and in the drug Primor

Question 5

What is sulfadiazine combined with and what drug is it found in?

Answer 5

Combined with trimethoprim in the drug Tribrissen

Question 6

Sulfasalazine is found in what drug and what is it used for?

Answer 6

Azulfidine and it is used for its antiinflammatory properties to treat IBD

Question 7

Sulfonamides can be described as what in reference to the location of their site of action?

Answer 7

Enteric or Systemic sulfas

Question 8

Which sulfa has a site of action within the intestinal tract, designed to not be absorbed into the body and Sulfasalazine is an example?

Answer 8

Enteric sulfas

Question 9

Which sulfa is intended to be absorbed from the intestinal tract into the body?

Answer 9

Systemic sulfas

Question 10

What is Sulfamethoxazole combined with and what drug is it found in?

Answer 10

Combined with Trimethoprim in the human drug Septra or Bactrim

Question 11

What are the potentiating compounds?

Answer 11

Trimethoprim and Ormetoprim

Question 12

What is the mechanism of action for sulfonamides?

Answer 12

They inactivate a key enzyme involved in the synthesis of folic acid

Question 13

The spectrum of action for potentiated sulfonamides is broad and includes what?

Answer 13

Gram-positive bacteria
Gram-negative bacteria
Protozoa organisms

Question 14

Which sulfonamide is not commonly used for its antimicrobial effect but its antiinflammatory effect in the colon to treat colitis?

Answer 14

Sulfasalazine

Question 15

When sulfasalazine is given orally only 1/3 is absorbed. What happens to the rest?

Answer 15

Stays in the bowel where it is transformed by colonic bacteria into an aspirin-like antiinflammatory drug

Question 16

When sulfasalazine is transformed into an aspirin-like antiinflammatory drug how does that benefit the colon?

Answer 16

It inhibits prostaglandin formation which decreases colonic inflammation and hypersecretion associated with large bowel inflammatory disease

Question 17

Sulfonamides and their potentiated forms are well absorbed in what in dogs and cats? What is the exception to this?

Answer 17

GI tract

Enteric sulfaonamide sulfasalazine

Question 18

What sulfonamide component may be trapped and degraded in the rumen of ruminents, reducing the amount absorbed?

Answer 18

Trimethoprim component

Question 19

The oral absorption for horses and ruminants varies a great deal based on what?

Answer 19

Diet and age

Question 20

Sulfonamides can readily traverse through which systems?

Answer 20

Prostate gland
Cross the placenta
Pass into the milk

Question 21

Due to what characteristic of sulfonamide allows it to penetrate the blood-brain barrier and achieve significant concentrations in the CNS and Cerebral spinal fluid?

Answer 21

Lipophilic nature

Question 22

Why are sulfonamides used to treat UTIs?

Answer 22

They are filtered by the glomerulus and actively secreted into the renal tubules achieveing high concentrations in urine

Question 23

What is the reason some clinicians administer trimethoprim-sulfonamide BID instead of the recommended SID?

Answer 23

The bacteriocidal effect of sulfonamide and its potentiating compounds will only be achieved if they penetrate the infection site together

Question 24

What is one of the more common reactions to Sulfonamides?

Answer 24

Decreased tear production resulting in Kertaoconjunctivitis sicca

Question 25

How do you treat Keratoconjunctivitis sicca?

Answer 25

Cyclosporine ophthalmic ointment (Optimmune)

Dogs must be treated for the rest of their lives

Question 26

What do skin reactions to the drug look like?

Answer 26

Pruritus
Swelling of the face
Hives

Question 27

What do hypersensitivity reactions to Sulfonamides look like?

Answer 27

Manifest as liver necrosis

Liver failure

Question 28

What breed of dog are more susceptible to hypersensitivity reaction to Sulfonamide?

Answer 28

Doberman pinschers

Question 29

What other reactions do Sulfonamides cause?

Answer 29

Thrombocytopenia
Leukopenia
Aneima
Crystalluria (damage renal tubules)

Question 30

What sulfa can produce salicylate toxicity (Aspirin toxicity) in cats?

Answer 30

Enteric sulfa sulfasalazine