PROBLEMS ARISING WITH THE USE OF ANTIMICROBIALS

Toxicity A. Local B. Systemic
Hypersensitivity Reactions: It may be in the form of rashes, urticaria, fever, itching, exfoliative dermatitis, angioneurotic edema or rarely anaphylactic shock
Drug resistance: Natural or Acquired
Acquired resistance may be developed by mutation or gene transfer
Mutation is stable and heritable genetic change that occurs spontaneously and randomly among microorganisms

Mutation may be single step or mutistep
Gene transfer: from one organism to other organism occur by
Conjugation
Transduction
Transformation
Resistant organism may be of following types
Drug tolerant means that the organism has altered binding proteins so that an antimicrobial may not reach at the site of action e.g. Methicillin resistant Staphylococcus aureus (MRSA)
Drug destroying means organism is producing some enzyme that inactivate the antibiotic e.g. production of beta lactamases various bacterias
Drug impermeable means that bacteria have altered porin channels through which antibiotic enter into bacterial cell