Pharmacokinetics
Classification & Uses
Pharmaco-dynamics
Adverse Effects & Populations
100
How is Sulfonamide administered and eliminated? How about Trimethoprim?
Orally or topically, kidneys. Orally or IV, kidneys
100
What are the classifications of Sulfonamide/Trimethoprim for the following. A. Susceptible organism? B. Mechanism of action?
A. Antibacterial B. Antimetabolites
100
Trimethoprim interferes with the production of which acid by inhibiting which enzyme?
A. Tetrahydrofolic Acid (folic acid derivative). B. Dihydrofolic reductase
100
What are the most common adverse effects?
Rash, N & V
200
How is Sulfonamide and Trimethoprim distributed throughout the body? Why?
It is well distributed to tissues and body fluids due to its high lipid solubility.
200
What is the main bacterial infection treated with Sulfonamide/Trimethoprim? What is the preferred combination drug for treatment?
Urinary Tract Infection. Trimethoprim/Sulfamethoxazole.
200
What is the significance of tetrahydrofolic acid?
It is necessary for bacterial/human cell devision and nucleic acid (DNA & RNA) synthesis (no cell division of bacteria cells = no new bacteria)
200
What is the syndrome associated with Sulfonamides that can occur? Name 2 manifestations.
A. Stevens-Johnson Syndrome. B. (Any of following) toxemia, fever, malaise, skin/mucous membrane lesions
300
Why is the use of Sulfonamide and Trimethoprim dangerous during pregnancy?
They readily cross the placenta (again, due to high lipid solubility)
300
A. Name 1 bacteria sensitive to Sulfonamides. B. Name 2 bacteria sensitive to Trimethoprim.
A. Escherichia coli. B. (Any of the following) Proteus mirabilis, K. pnuemoniae, Enterobacter species, S. saprophyticus
300
Sulfamethoxazole interferes with the synthesis and growth of which acid via the inhibition of formation of which acid?
Bacterial folic acid via the inhibition of dihydrofolic acid formation.
300
Crystalluria is another adverse effect of Sulfonamides. Which organ is damaged by this? Most commonly it is associated with what? To reduce the risk of organ damage what should be done?
A. Kidney B. older sulfonamides (they become less soluble, which causes the drug to be crystallized in kidneys, bladder, & ureters). C. Increase fluid intake to 8-10 glasses of water per day.
400
Which drug has a higher concentration in the blood, S or T? What is the percentage?
Sulfonamide - 80%. This is why they are both used as a combination drug since Trimethoprim is only slightly metabolized; thus it's concentration is low in the blood and high in the urine
400
What type of pneumonia is treated with TMP/SMZ? What type of patients are most susceptible to the bacteria that causes it? (Name the bacteria, the type of pts effected, examples of pts).
Pneumocystis Pneumonia. Pneumocystis jiroveci. Immunosuppressed pts ie AIDs pts, organ transplant recipients, and cancer pts.
400
What are 4 contraindications with TMP/SMZ?
Infants <2 months of age, individuals with kidney damage, individuals with folate deficiency, people with hypersensitivity to sulfonamides.
400
Trimethoprim causes high concentrations by suppressing excretion of which electrolyte? What can occur due to these high levels? What can be done to avoid this adverse effect? Which age group is most susceptible?
A. Potassium B. Hyperkalemia. C. Monitor serum potassium and monitor pts who are taking other meds that cause elevated potassium levels. D. Elderly
500
Trimethoprim/Sulfamethoxazole is used to treat bacterial infections. What is the ratio required to achieve optimal therapeutic effects? What dose is needed to maintain this? How often is it given during a 24 hr period? (Math time!)
1:20. 80mg TMP & 400mg SMZ (1:5 ratio) given every 6 hours.
500
What is a third infection treated by TMP/SMZ? Vancomycin is also used to treat this infection; however, it is not preferred for outpatient therapy. Why is this?
Community-Associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Although both can be given orally, Vancomycin must be given IV to achieve its therapeutic effect against CA-MRSA)
500
Are S & T bactericidal or bacteriostatic?
Bacteriostatic (they stop bacteria from reproducing).
500
As mentioned earlier, both S & T readily cross the placenta. They also have the ability to enter breast milk. Thus, which patients should NOT use this drug? What 2 dangers can occur?
A. Pregnant women and those whom are breast feeding. B. Birth defects & increased folate deficiency in pregnant women.
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