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

2020
Views:

386

Pages:

1
Author:

ilikemyicons0y5

2.1 – “Le TTour our de Cycline Cyclines”: s”: Tetracyclines • Tetracyclines (cycles) inhibit bacterial protein synthesis by binding to and inhibiting ribosomal transcription; bacteriostatic (ribosome paper jammed typewriter). Includes doxycycline, demeclocycline & minocycline. Enter microbes and concentrate inside. Bind 30S rRNA subunit, blocking translation (30 second timer in secretary’s hand). • Broad spectrum (prism medals), with activity against G+ & G- including MRSA (no mercy pharaoh in 1st place), although not first line for MRSA. Also treats rickettsia & atypical infections (often first line). • Administered orally. Absorbed primarily in proximal small intestine. Chelate metals, so concomitant administration of administration of multivalent cations causes decreased absorption (Ca, Fe, Mg medals). Eliminated fecally, so can be used safely in renal failure patients (colon pipeline). • Indications: o Tetracyclines, doxycycline especially, are effective against tick-borne illnesses including Rickettsia, Ehrlichia, Francisella, Borrelia (early stages or disseminated) (deer with ticks). o Doxycycline for many other zoonoses ▪ Brucellosis (cow in background) ▪ Q-fever (Coxiella) (sheep with Q horns) ▪ Plague (Yersinia) (squirrels) o Doxycycline for one week first line in chlamydial cervicitis, urethritis. Also used in PID, endometritis; in this case, consider doxy + cephalosporin (female biker with uterine handlebars) o Oral doxycycline is a treatment mainstay for atypical community acquired PNA including mycoplasma, chlamydia (snowshoer, clam bra) o Used in moderate to severe acne with anaerobic bacteria (mountains) • Resistance can develop either by efflux pumps (efflux pump) or ribosomal mutations. • Adverse effects o Teratogenic (pregnant woman & tarantula). Causes enamel dysplasia d/t deposition in calcium tissue (baby eating calcium medal) o Nausea, vomiting, diarrhea (mud puddle) o Photosensitivity with systemic administration (paparazzi taking photos) o Fanconi syndrome (Type 2 proximal renal tubule acidosis) has been associated with use of expired tetracyclines o Demeclocycline impairs the action of antidiuretic hormone (ADH) at its receptor, causing nephrogenic diabetes insipidus, which manifests as urinary frequency and polydipsia. A water deprivation test would reveal inappropriately dilute urine in the context of decreased water intake as a result of nonfunctional ADH