Chloramphenicol interactions

Harper JM, Yost RL, Stewart RB, Ciezkowski I Phenytoin-chloramphenicol interaction. Drug Intell Clin Pharm (1979) 13, 425-9. 

The preferred substrates of acetyltransferases are amino-groups of antibiotics, like chloramphenicol, strepto-gramin derivatives, and the various aminoglycosides. The modification is believed to block a functional group involved in the drug-target-interaction. All acetyltransferases use acetyl-coenzyme A as cofactor. 

Phenytoin interacts widi many different drugp. For example isoniazid, chloramphenicol, sulfonamides, benzodiazepines, succinimides, and cimetidine all increase phenytoin blood levels. The barbiturates, rifampin, theophylline, and warfarin decrease phenytoin blood levels. When administering the hydantoins with meperidine, die analgesic effect of meperidine is decreased. 

Monitoring Monitoring serum levels is important because of the variability of chloramphenicol s pharmacokinetics. Monitor serum concentrations weekly monitor more often in patients with hepatic dysfunction, in therapy more than 2 weeks, or with potentially interacting drugs. 

Drugs that may interact with zalcitabine include antacids, chloramphenicol, cisplatin, dapsone, didanosine, disulfiram, ethionamide, glutethimide, gold, hydralazine, iodoquinol, isoniazid, metronidazole, nitrofurantoin, phenytoin, ribavirin, vincristine, cimetidine, metoclopramide, amphotericin, aminoglycosides, foscarnet, antiretroviral nucleoside analogs, pentamidine, and probenecid. 

Disp Tabs, susp SE D, dizziness, rash, eosinophilia, T transaminases Interactions T Nephrotox W/ aminoglycosides, loop diuretics T effects W/probenecid i effects W/ antacids, chloramphenicol EMS T Risk of nephrotox w/ loop diuretics monitor for signs of electrolyte disturbances and hypovolemia d/t D monitor pt for super Infxn OD May cause NA /D, Szs, muscles spasms 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... 

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