1st test anasthesia Flashcards
Who is in charge of controlling all physiological and physiopathological functions of the organism, administrating drugs to produce desired effects and avoid undesired effects or toxicity, as well as control renal function, hepatic function, temperature etc?
anesthesiologist
owner of px controlling all biological and fisiopathological functions during times in OR
therapeutic objective = give and maintain a dose in determined places for a desired effect
analgesia, amnesia
art of anesthesiology
must adjust dose and velocity of administration depending on clinical response of px
- (a lot of drugs have to be adminstered slowly)
want desired effect while avoiding undesired side effects/toxicity
what is succinilcoline?
it is a depolarizing relaxer
what happens if succilycholine is rapidly administrated?
px will present fasciculations or involuntary movements
px se retuerce
increases gastric , intraocular and incracraneal pressure –> broncoaspiration if px ate
3 pillars of anesthesiology
physiology, pharmacology, anatomy
ej of how to block a nervous transmission
local anesthetic like lidocaine to interrupt transmission of pain sensation
side effects of lidocaine
hipotension
role of amnesia in this subject
elimination of all memory for a 6-12 hr period is important
The point of general inhaled anesthesia?
- Maintain a central depression or an anesthetic coma for surgeon to operate
What are the 3 aspects/principles of anesthetics?
pharmacological
pharmacokinetic
pharmacodynamic
pharmacological principal
○ Professional has knowledge of drug (precipirates in sun? pH? Needs to be in cold? Best administration, disolvent)
liposoluble vs hydrosoluble
drug known to irritate a lot veins , painful
propofol
pharmacodynamics vs pharmacokinetics
Pharmacodynamics is the study of how a drug affects an organism, whereas pharmacokinetics is the study of how the organism affects the drug. …
what are the 4 aspects/parameters of Pharmacokinetics
Absorpion
distribution (volume)
metabolization (velocity ,time , etc)
elimination
absorption depends on what 4 aspects?
Biodisponibilidad/Bioavailability)
Perfusion grade where it is administered (Plasma concentration of drug is greater when deposited somewhere with a lot of irrigation)
Velocity of administration
Route of administration (determines velocity of absorption)
what does distribution depend on?
○ Depends on physical chemical cx of drug, CO, and regional blood flow
Different types of metabolization?
oxidation in liver
Reduction
Hydrolysis
types of elimination
through kidney or hepatobiliary, pulmonary
info about drug metabolism
Drug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems.
The study of drug metabolism is called pharmacokinetics.
The metabolism of pharmaceutical drugs is an important aspect of pharmacology and medicine. For example, the rate of metabolism determines the duration and intensity of a drug’s pharmacologic action.
The metabolism of xenobiotics is often divided into three phases:- modification, conjugation, and excretion. These reactions act in concert to detoxify xenobiotics and remove them from cells
Biotransformation occurs only for the agents at physiological pH, having low molecular weight and less complex. Biotransformation is a process specifically to make agents more polar and excretable. If biotransformation does not occur, drugs may have longer duration of action, and undesired effects are observed along with desired ones. Biotransformation, in fact, is the inactivation of pharmacological action of drugs.
Cytochrome P450:
Cytochromes are the heme proteins, present abundantly within the living kingdom. They have about thousand known kinds. Only 50 of these heme proteins are found within the humans, which are divided into 17 families and sub-families. Name is derived because it is a heme protein (abbreviation cyp) and 450 because it reacts with carbon monoxide and during the reaction absorbs light at 450 nm.
NADPH
NADPH is a flavoprotein, less abundant than cyp 450.
For every 10 molecules of cytochrome P450, only one NADPH cytochrome reductase is present
Biochemical Reactions:
Phase I reactions
Phase II reactions
Phase I reactions:
Phase I reactions are non-synthetic catabolic type of chemical reactions occurring mainly within the ER. They are the reactions in which the parent drug is converted into more soluble excretable agents by introduction or unmasking of functional component.
Example includes phenobarbitone, aromatic hydroxylation of which abolishes its hypnotic activity. Similarly, metabolism of azathioprine produces 6-mercaptopurine.
Drug products, which are water soluble are excreted by the kidneys. Sometimes this is not true and phase I compounds do not result in true inactivation and may act as functional components of phase II reactions.
Phase I reactions include:
Oxidation
Reduction
Hydrolysis
ej , reduced, hydrolisized
Reduction
Chloramphenicol, dantrolene, clonazepam
Hydrolysis
Esters: procaine, suxamethonium and aspirin
Amides: procainamide, lidocaine
oxidation vs reduction
Oxidation is a reaction in which an atom, molecule or compound loses anelectron. OIL = Oxidation Is Lost; RIG= Reduction Is Gain LEO = Lose Electron in Oxidation; GER = Gain Electron in Reduction (LEO the lion says GER)
oxidation in the liver/ types
Types of Biotransformation:
Biotransformation taking place due to different enzymes present in the body/cells is known as enzymatic elimination.
- Enzymatic
a. Microsomal
Microsomal Biotransformation:
Enzymes responsible are present within the lipophilic membranes of endoplasmic reticulum. After isolation and putting through homogenization and fractionation, small vesicles are obtained, known as microsomes. They possess all functional, morphological properties of endoplasmic reticulum i.e. smooth and rough. Smooth ER is concerned with biotransformation and contains enzyme components while the rough ER is mainly concerned with protein synthesis.
Enzymes isolated from ER possess enzymatic activity termed as microsomal mixed function oxidase system.
Components:
Cytochrome P450 (ferric, ferrous forms)
NADPH (flavoprotein)
Molecular oxygen
Membrane lipids
b. Non-microsomal
Non-Microsomal Biotransformation:
The type of biotransformation in which the enzymes taking part are soluble and present within the mitochondria.
- Non-enzymatic (Hofmann Elimination)
Non Enzymatic Elimination:
Spontaneous, non-catalyzed and non-enzymatic type of biotransformation for highly active, unstable compounds taking place at physiological pH. Very few drugs undergo non-enzymatic elimination. Some of these include:
Mustin HCl converted into Ethyleneimonium
Atracurium converted into Laudanosine and Quartenary acid
Hexamine converted into Formaldehyde
Chlorazepate converted into Desmethyl diazepam
Hydrolysis
is a reaction in which a molecule or compound is broken down, by the addition of a water molecule (usually with an acid to catalyze the reaction)
atracurium and Cisatracurium are ?
non polarizing relaxers
different routes of administration of drugs
oral = enteral sublingual rectal subcutaneous intramuscular Intravenous Intratecal, BSA, BPD Pulmonary