Question | Answer |
Prophylaxis | Use of antibiotics to prevent infection rather than treat an infection |
Empiric | An educated guess; the use of antibiotics to cover a variety of possible organisms or the most likely |
Pathogen | Organisms that are causing an active infection |
Normal Flora | Those organisms normally found on the host. Usually considered non-pathogenic |
Suprainfection | Alterations in normal flora which allow the overgrowth of other organisms |
Bactericidal | Kills the organism |
Bacteriostatic | Inhibits the organism’s growth |
MIC | minimum inhibitory concentration |
Synergy | use of two antibiotics with different mechanisms of action to achieve better kill or inhibition of the organism |
Signs and Symptoms that Confirm the Presence of Infection | - fever, chills, sweats, weakness, malaise
- sputum production (quantity, consistency, color, odor)
- chest x-ray, WBC counts, urine analysis
- inflammation (tender, edematous, erythematous), oozing, pus |
Folate Antagonists (Sulfa Drugs/ Sulfonamides) Mechanism of Selective Toxicity | - Bacterial cells are impermeable to folic acid and must synthesize folic acid to survive
- Human cells do not synthesize folic acid. We receive folic acid as a vitamin in our diet |
Folate Antagnoists (Sulfa Drugs/ Sulfonamides)MOA | Sulfonamides use up much of the enzyme needed to convert PABA to folic acid, thus decreasing folic acid production |
Sulfonamides are active against | - Proteus mirabilis
- Escherichia coli
- Methicillin-resistant Staphylococcus Aureus (MRSA)
- Pneumocystis Jiroveci (formerly identified as
Pneumocystis carinii) |
Sulfonamides Therapeutic Indications | - Urinary tract infections (Main Use)
- Topical for burns and wounds
- Some ophthalmic infections
- Pneumocystis pneumonia (treatment and prophylaxis) |
Sulfonamdies Adverse Effects | - Allergic Reactions - rashes, photosensitivity, Stevens-Johnson syndrome
- Nephrotoxicity - Crystalluria - adequate hydration - drink lots of water. Contraindicated in renal failure
- Kernicterus - displace bilirubin from protein binding sites |
Sulfonamides Drug Interactions | Warfarin, Phenytoin |
Trimethoprim - Drug Class | Folate Antagonists |
Trimethoprim MOA | - Dihydrofolate reductase inhibitor
- Dihydrofolate reductase converts folic acid to its active form, tetrahydrofolic acid |
Trimethoprim Pharmacokinetics | Similar to Sulfonamides |
Trimethoprim Adverse Drug Reactions | Can produce effects of folate deficiency if given in very high doses |