University:
University of North Carolina at Chapel Hill
Course:
NURS 312 | Pharmacology
Academic year:

2020
Views:

171

Pages:

1
Author:

rehinhea0c

4.2 – “Trick or Treat, pyrimetha pyrimethamine/sulfadiazine) mine/sulfadiazine) Smell my Drugs”: Sulfa drug s (TMP/S (TMP/SMX, MX, • Sulfonamides are anti-folate drugs. Mammals don’t synthesize folate, deriving it from dietary sources. However, many bacteria synthesize folate from Para-aminobenzoic acid (PABA) (Panda papa, with purine cookies), making them susceptible to disruption of the process. PABA converted to dihydrofolic acid by dihydropteroate synthase → THF (bamboo with 2 & 4 leaves – folate found in leafy greens – on 1st & 2nd steps). Inhibition of folate → inhibition of DNA synthesis • Trimethoprim/sulfamethoxazole (creepy twins) o SMX is a PABA analog that blocks dihydropteroate synthase (dihydropteroate affected by sulfa egg dropping cookies) ▪ Adverse effects (note that many are common to all sulfa drugs, not just SMX) (adverse effects on sidewalk) • 2nd most common allergy after β-lactams. Include fever, rash, urticaria (kid in devil costume doing an itchy jig) • Anemias may develop in allergy o Hemolytic anemia in G6PD deficiency (watermelon w bite cell) • Stevens-Johnson syndrome – rare, but has been seen (red mask sloughing off) o Technically, is a tengu mask and should remind us of toxic epidermal necrolysis (TEN) • Type IV RTA (mad scientist with 4 tubes of acid) o →↑K (shape) • Interstitial nephritis with monocytic infiltrate (little blue candies in kidney shaped bag) • Photosensitivity (snapping photos) • Kernicterus in neonate when used in last month of pregnancy. Displace bili bound to serum albumin →↑ free unconjugated bili (kernicteric candy corn baby brother) • Displaces other drugs from albumin e.g. warfarin (photos displaced from album) o Warfarin → ↑ anticoagulation leading to bleeding (bloody mother) • Inhibit CYP450 metabolism (sulfa egg vandalism) o TMP (TP): blocks DHFR (2 leaves ducking = reductase) ▪ Adverse effects: • Folate inhibition → DNA inhibition. Can cause pancytopenia a/o megaloblastic anemia (empty pan, firework blasts) • Teratogenic in 1st trimester d/t neural tube defects (spider décor) o Bacteriostatic individually, bactericidal in combination. o Often first line Tx for G- bugs for GI & urinary tract bacteria (red costume and porta-potty). Also G+ (purple fence) ▪ UTI (porta-potty with TP & eggs) ▪ Treats acute prostatitis in men (kid shoving eggs down man’s pants) ▪ MRSA (pharaoh with “No Mercy” graffiti) – but not first line ▪ Drug of choice for Nocardia (card dealing partly acid-fast cowboy painting nocardia) ▪ PJP (old ping pong man in PJs with immunocompromised cane). Used for both treatment and PJP prophylaxis with CD4 < 200 (old man; mailbox no.) ▪ Toxoplasmosis prophylaxis with CD4 < 100 (crazy toxo cat lady with Gandhi gat for toxoplasma gondii; mailbox no.) . • Pyrimethamine/sulfadiazine (pyramid witch hat, dyed super eggs) o Similar MOA to TMP-SMX o Treat ▪ Toxoplasmosis