Which of the following is drug of choice for pseudomembranous enterocolitis is?
Ans. a. Oral vancomycin (Ref: Katzung 12/e p802-803; KDT 7/e p757, Sabiston 19/e p1334-1335; Schwartz 9/e p1057; Bailey 26/e 1159. 25/e p1165)Drug of choice for pseudomembranous enterocolitis is oral vancomycin.VancomycinGlycopeptide antibioticQEffective against MRSAQ, Strep, viridans, Enterococcus and CL difficileQMechanism of Action:Acts by inhibiting bacterial cell wall synthesisQ(binds terminal D-ala-D-ala' sequence)Uses:Oral: Antibiotic associated pseudonembranous colitisIntravenous: Serious MRSA infection, Enterococcal endocarditis. Empirical therapy of bacterial meningitis, Pneumococcal infectionsQSide-Effects:High systemic toxicityQCauses plasma cone, dependent nerve deafnessQ which may be permanentDose related kidney damageQHistamine release: Skin allergy, fall in BP and Red man syndromeQRapid IV injection has caused chills, fever, urticaria and intense flushing called 'Red man syndrome'QPseudomembranous ColitisPMC is caused by C. difficile, a gram-positiveQ bacillus.C. difficile colitis is the leading cause of nosocomially acquired diarrheaQ.Pathogenesis:Colitis is thought to result from overgrowth of this organism after depletion of the normal commensal flora of the gut with the use of antibioticsQ.ClindamycinQ was the first antimicrobial agent associated with C. difficile colitis, almost any antibiotic may cause this disease.Toxins produced: Toxin A (an enterotoxin) and toxin B (a cytotoxin)Q.Immunosuppression, medical comorbidities, prolonged hospitalization or nursing home residence, and bowel surgery increase the riskQ.Clinical Features:The spectrum of disease ranges from watery diarrhea to fulminant, life-threatening colitisDiagnosis:Diagnosis is made after detection of one or both toxins by:Stool cytotoxin assayQELISAQColonoscopy: Characteristic ulcers, plaques, and pseudomembranesQTreatment:Immediate cessation of the offending antimicrobial agentQ.Mild disease:Oral metronidazole (10-day course): Drug of choiceQOral vancomycin: Second-line agent, used in metronidazole allergy or in recurrent diseaseQ Severe disease: Bowel rest. IV hydration, and IV metronidazole or oral vancomycinQ.Fidoxamicin (specific RINA polymerase inhibitor against C. difficile)
Oral vancomycin
Cephalexin
Clindamycin
Penicillin
Penicillin & Cephalosporin