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RavLect18: TCNs
Tetracyclines
Question | Answer |
---|---|
Tetracycline MoA | Bind to the 30S ribosomal subunit, reversibly inhibiting the binding of aminoacyl-tRNA (no protein synth, no cell wall) Mainly Static |
Tetracycline ADRs | Erosive/sclerosing Renal fail @ expirn Teeth staining; bone growth impaired; teratogenic Photosenstivity (highest w/ democlocycline) Hepatotoxicity (w/ high dose in renal failure) NVD anti-anabolic: raise BUN, acidosis, hyperphosphatemia |
Minocycline ADRs | Vertigo (more in women) Skin & mucous membrane pigmentation Lupus-like symptoms |
TCN DDIs | Anticonvulsants (Carbamazepine, Phenytoin, Phenobarbital) decrease [TCN] Antagonistic w/ PCNs (static, while PCNs are cidal) Lowers efficacy of OCs! Complex w/ Fe, Zn, Ca, Mg, Al, bismuth, binding resins Isotretinoin causes benign cranial hype |
TCN on food/empty stomach? | Tetracycline on empty stomach Doxy & Minocycline w/ food |
TCN IV or PO? | PO: TCN, Doxycycline, Minocycline IV: Doxy, Mino, Tigecycline |
Doxycycline | DON'T inject IM! It will burn tissue to death Don't dose adjust in renal dysfunction |
Tetracycline PK | TCNs distribute to all tissues, liver, bile, prostate, urine, CSF, Synovial |
Tigecycline (Tigacil) | distributes best to GI organs. Indicated for IA infections. Can Tx DR enterococcus. Also for cSSIs. Don't give in pneumonia; increases mortality! Requires dose adjustment in hepatic impairment Elevates LFTs NV (slow rate to fix), AAD |
Drugs for IA infections | Tigecycline, cefoxitan and cefotetan, moxiflox, iminem, erbipenem. Zosyn & Unasyn too, but freq dosing is inconvenient |
Tetracycline SoA (all TCNs except Tigecycline) | They treat rare/WEIRD organisms. 2nd line for atypicals (after 1st line Quinolones) along with macrolides broad spectrum of aerobic and anaerobic bacteria including intracellular pathogens G- & G+ We don't use very often though b/c of ADRs |
Demeclocycline | for Tx of SIADH only! Causes hyponatremia, fluid overload, concentrated urine. |
General Use for TCNs | CAP Non-gonococcal UTI (chlamydia trachomatis) PID - IV doxycycline w/ cefoxitin or cefotetan Atypical pneumonia/bronchitis: Chlamydia pneum, C. psittaci, Mycoplasma pneu, Legionella Lyme disease Rickettsia H. pylori (TCN w/ other drug |
Which drugs should NOT be used in babies? | TCNs & Quinolones |