Chloramphenicol action

Modified Hammett substituent constants (100) were used by Garrett et al. to describe the bacterostatic activities of a series of sulfanilamides (101). Hansch also used the homolytic substituent constants (ER) of Yamamoto and Otsu (102) in analyzing the activity of selected chloramphenicol derivatives (103). The resulting correlations led to the hypothesis of a free-radical mechanism of chloramphenicol action. Substituent measures of it electron charge density distributions (07 and ov)... 

Pestka S. Studies on the formation of transfer ribonucleic acid-ribosome complexes. VIH. Survey of the effect of antibiotics on N-acetyl-phenylalanyl-puromycin formation Possible mechanism of chloramphenicol action. Atch Biochem Biophys 1970 136 80-88. 

Stmcture-activity and mechanism of action studies indicate that the requirements for chloramphenicol activity are the D-threo-configuration, the... 

Mr. Beeves has a severe infection and is receiving chloramphenicol IV. The nurse notes several bruises on Mr. Beeves arm after 2 days of therapy. What action (if any) should the nurse take. Give a rationale for your answer. 

Bacterial ribosome function Aminoglycosides Tetracyclines Chloramphenicol Macrolides, azalides Fusidic acid Mupirocin Distort SOS ribosomal subunit Block SOS ribosomal subunit Inhibits peptidyl transferase Block translocation Inhibits elongation factor Inhibits isoleucyl-tRNA synthesis No action on 40S subunit Excluded by mammalian cells No action on mammalian equivalent No action on mammalian equivalent Excluded by mammalian cells No action on mammalian equivalent... 

Action Monobactam, -1- cell wall S5mth Dose Adul. 1—2 g IV/EM q6-12h Peds. Premature 30 mg/kg/dose IV ql2h Term children 30 mg/kg/dose q6-8h X in renal impair Caution [B, +] Disp Inj SE NA /D, rash, pain at inj site Interac tions T Effects W/probenecid, aminoglycosides, i-lactam antibiotics X effects W7 cefoxitin, chloramphenicol, imipenem EMS Monitor for S/Sxs of super Infxn may cause aUCTgic Rxns rare cross-sensitivity Rxns to penicillins and cephalosporins have been rqwrted OD May cause Szs symptomatic and supportive... 

WARNING Anaphylactic Rxns w/ use use only if oral Fe not possible administer where resuscitation techniques available Uses Fe deficiency when cannot supl PO Action Fe supl Dose Adul. Iron defic anemia Estimate Fe deficiency, give 25-100 mg IM/IV /d until total dose total dose (mL) = [-.0442 x (desired Hgb - observed Hgb) x LBW] + (0.26 x LBW) Iron replacement, blood loss Total dose (mg) = blood loss (mL) x Hct (as decimal fraction) max 100 mg/d Peds >4 mo. As for adults max 0.5 mL (wt <5 kg), 1 mL (5-10 kg), 2 mL (>10 kg) p dose IM or direct IV Caution [C, M] Contra Anemia w/o Fe deficiency. Disp Inj SE Anaphylaxis, flushing, dizziness, inj site inf Rxns, metallic taste Interactions X Effects W/ chloramphenicol, X absorption of oral Fe EMS Anaphylactic Rxns common taking oral Fe t risk of tox and SEs OD May cause N/V, HA, muscle/joint pain and fev symptomatic and supportive Iron Sucrose (Venofer) [Iron Supplement] Uses Fe deficiency anemia w/ chronic HD in those receiving erythropoietin Actions Fe r lacement. Dose 5 mL (100 mg) IV on dialysis, 1 mL (20 mg)/min max Caution [C, M] Contra Anemia w/o Fe deficiency Disp Inj SE Anaphylaxis, -1- BP, cramps, N/V/D, HA Interactions i Absorption OF oral Fe supls EMS See Iron Dextran OD See Iron Dextran... 

Mupirocin (Bactroban) [Topical Anti-infective] Uses lmpetigo CTadicate MRSA in nasal carriers Action -1- Bactmal protein synth Dose Topical Apply small amount to area 3 x /d x 5-14 d Nasal Apply bid in nostrils x 5d Caution [B, ] Contra Do not use w/ other nasal products Disp Oint, cream SE Local irritation, rash Interactions X Bacterial action W/ chloramphenicol EMS Monitor pt for super Infxn OD Unlikely, but not expected to produce life-threatening Sxs... 

Uses Infxns of resp tract, skin/soft tissue, scarlet fevCT, S5 philis Action Bactericidal -1- cell wall synth Dose Adults. 0.6-4.8 million Units/d in doses ql2-24h give probenecid at least 30 min prior to PCN to prolong action Feds. 25,000-50,000 Units/kg/d IM daily-bid Caution [B, M] Contra AU gy Disp Inj SE Pain at inj site, int stitial n hritis, anaphylaxis Interactions t Effects W/probenecid t penicillin 1/2-life Wf ASA, furosemide, indomethacin, sulfonamides, thiazide diuretics T risk of bleeding W/ anticoagulants -1- effects Wf chloramphenicol, macrolides, tetracyclines -1- effects OF OCPs EMS See Penicillin G, Aqueous OD See Penicillin G, Aqueous... 

PCN-sensitive staph) Action Bact icidal -1- cell wall synth Spectrum Most gram(+), including str Dose Adults. 250-500 mg PO q6h, q8h, q 12h Peds. 25-50 mg/kg/25h PO in 4 doses -1- in renal impair on empty stomach Caution [B, M] Contra Allergy Disp Tabs, susp SE GI upset, int stitial nephritis, anaphylaxis, convulsions Interactions -1- Effects W/ ASA, probenecid t effects OF MTX t risk of anaphylaxes W/BB -1- effects W/ chloramphenicol, macrolides, tetracyclines X effects OF OCPs EMS Monitor for sup Infxn T effects of anticoagulants monitor for signs of electrol5rte disturbances and h5 povolemia d/t D OD May cause N/D and Szs activated charcoal may be effective... 

Phenytoin (Dilantin) [Anticenvulsant/Hydantoin] Uses Sz disorders Action X Sz spread in the motor cortex Dose Load Adults Peds. 15-20 mg/kg IV, 25 mg/min max or PO in 400-mg doses at 4-h intervals Maint Adults. Initial, 200 mg PO or IV bid or 300 mg hs then follow levels Peds. 4-7 mg/kg/24h PO or IV -s- daily-bid avoid PO susp (erratic absorption) Caution [D, +] Contra Heart block, sinus bradycardia Disp Caps, susp, inj SE Nystag-mus/ataxia early signs of tox gum hyperplasia w/ long-term use. IV BP, bradycardia, arrhythmias, phlebitis peripheral neuropathy, rash, blood dyscrasias, Stevens-Johnson synd Notes Levels Trough Just before next dose Therapeutic Peak 10-20 mcg/mL Toxic >20 mcg/mL phenytoin albumin bound, levels = bound free phenytoin w/ i albumin azotemia, low levels may be therapeutic (nl free levels) Interactions T Effects W/ amiodarone, allopurinol, chloramphenicol, disulfiram, INH, omeprazole, sulfonamides, quinolones, trimethoprim t... 

---