Chelating Agents & Treatment of Poisoning Supportive Therapy Blood pressure, ECG, blood gas analysis, urine output and respiration are to be monitored To correct coagulation parameters, blood transfusion may be needed ANTISNAKE VENOM Antivenom is the only specific antidote to snake venom Antivenom is immunoglo- 403 bulin purified from the serum or plasma of a horse or sheep that has been immunised with the venoms of one or more species of snake Antivenom should be given by the intravenous route Freeze dried (lyophilised) antivenoms are reconstituted, usually with 10 ml of sterile water for injection per ampoule Adrenaline should always be drawn up in readiness before antivenom is administered for any possible anaphylactic reactions This page intentionally left blank Section 12 Dental Pharmacology This page intentionally left blank r r e e t t p p a CChh 12.1 1.4 Antiseptics & Pharmacodynamics (Mode of Action of Drugs) Disinfectants These are the agents which inhibit or kill microbes on contact Conventionally Factors which Modify the Activity of Germicides • Antiseptics are used on living surfaces • Disinfectants are used for inanimate objects The practical distinction of these two agents is on the basis of a growth inhibiting or direct lethal action There are concentration dependent Germicide covers these two category Potency of germicide is generally expressed by its “phenol coefficient or Rideal Walker (RW) coefficient” – “which is the ratio of the minimum concentration of the test drug required to kill a 24 hour culture of B typhosa in 7.5 minutes at 37.5°C to that of phenol (as standard) under similar conditions.” Temperature & pH Period of contact with the microorganisms Nature of microbes involved – Spectrum of activity of majority of antiseptic disinfectants is wide reflecting non selectivity of action However, some are selective e.g hexachlorophene, chlorhexidine, quarternary ammonium antiseptics, gentian violet, acriflavine are more active for gram +ve than gram –ve Silver nitrate is highly active against gonococci and benzoyl peroxide against P acnes In dentistry, they are used for sterilization of certain instruments and prevention and treatment of dental plaque and peridental diseases They are also used in root canal therapy (RCT), treatment of acute necrotizing gingivitis and other infective oral conditions Antiseptics and disinfectants are also used as ingredient in various dentifrices Mechanism of Action (Cidal or Inhibiting Action) Size of inoculum Presence of blood, pus & other organic matter i Oxidation of bacterial protoplasm ii Denaturation of bacterial proteins including enzymes ... acriflavine are more active for gram +ve than gram –ve Silver nitrate is highly active against gonococci and benzoyl peroxide against P acnes In dentistry, they are used for sterilization of certain... Modify the Activity of Germicides • Antiseptics are used on living surfaces • Disinfectants are used for inanimate objects The practical distinction of these two agents is on the basis of a growth...This page intentionally left blank Section 12 Dental Pharmacology This page intentionally left blank r r e e t t p p a CChh 12.1 1.4 Antiseptics & Pharmacodynamics