DRUG METABOLISM

DRUG METEBOLISM
All organism are exposed :
- To foreign chemical compounds
- In the air, water, and food
Pharmacologically active foreign chemicals
Endogenous substances
Metabolic pathways :
- To alter their activity & their susceptibility to excretion

THE NEED FOR DRUG METABOLISM
Portals for entry of external molecules into the body (pulmonary alveoli, intestinal epithelium) contain transporter molecules of the P-glycoprotein family → expel undersired molecules immediately after absorption.
Some foreign molecules are absorbed : toxic
Require mechanisms biotransformation :
- Mechanism by which the body terminates the action of some drugs
- It serves to activate prodrugs
More drugs : relatively lipid soluble
- Favorable to absorption across membranes
- Very slow removal from the body because the molecule would also be reabsorbed from the urine in renal tubule

A. PHASE I REACTIONS
• Oxidation
• Reduction
• Deamination
• Hydrolysis
B. PHASE II REACTIONS
• Are synthetic reactions
• Addition (conjugation) of subgroups to-OH, -NH2, and –SH functions
• The subgroups hat are added include glucuronate, acetate, glutathione, glycine, sulfate, and methyl groups.
• Relatively polar →less lipid soluble

SITE OF DRUG METABOLISM
• Liver
• Kidneys
• Blood
• Intestinal wall

DETERMINANTS OF BIOTRANSFORMATION RATE
• Vary markedly among different individuals
• Genetic
• Drug-induced
• Age
• Disease-related
• Gender

BIOTRANSFORMATION RATE
• Rate of biotransformation → the primary determinant of clearance
• Variations in drug metabolism must be considered carefully when designing a dosage regimen
• Smoking → enzyme induction in the liver & lung → ↑ the metabolism drugs

GENETIC FACTORS
• Hydrolysis of esters
• Acetylation of amines
• Oxidation

GENETIC COUNSELING

Genetic counseling is a comunication proces which the human problems associated with the occurrence, or the risk of occurrence, of a genetic disorder in family. This process involves and attempt by one or more appropiatel, trained person to help the individual.

What are genetic counselors ?

Genetic counselors are health professionals with specific graduate degrees and experience in the areas of medical genetics and counseling. Most enter the field from a variety of disciplines, including biology, genetics, nurzing, psychology, public health and social network.

Genetic counselors work as members of a healthcare team, providing information and support to families who have members with birth defects or genetic disorders and to families who may be at risk for a variety of inherited condition. They identify families at risk, investigate the problem present in the family, inteprete information about the disorder, analyze patterns and risks of recurrence, and review available options with the family.

What is genetic testing?

A genetic test is the analysis of human DNA, RNA, chromosomes, protein, or certain metabolites in order to detect alterations related to a heritable disorder. This can be accomplished by directly examining the DNA or RNA that make up a gene (direct testing), looking at markers co-inharited with a disease-causing gene (linkage testing), assaying certain metabolites (biochemical testing), or examining the chromosomes (cytogenetic testing).

Selected methodology terms are used in the Gene Tests Laboratory Directory. Although genetic testing shares some features in common with other kinds of laboratory testing, in many ways it is unique and requires special consideration :

Points to consider :

* Genetic testing may be used for medical management and for personal decision-making.

* Genetic test result usually apply not only to the patient but also to other family members.

* Genetic testing may be performed in the context of a genetics consultation and should be informed consent, test interpretation, and follow up medical and psychosocial service as indicated.

* Because most genetic disorders are rare, genetic testing is often done only by specialized laboratories.

* Intense research efforts in molecular genetics result in rapid development and availability of new genetic test; therefore, healthcare providers need to continously update their knowledge.

* In order for genetic testing to yield meaningful result :

a. multiple test methodologies may be required

b. other family members may need to be tested

c. a genetic consultation may be appropiate 

PEDIATRIC BASIC LIFE SUPPORT

Definition :
The process that provides oxygenation and ventilation to reserve cardiac arrest. Prompt and proper Pediatric Basic Life Support (PBLS), important in infants / children.

Assesment And Treatment
- Safe approach
- Are you alright?
- Airway opening manoevres
- Look, listen, feel
- Breaths
- Check pulse
- Start CPR (20x 5:1)
- Call emergency
- Services

Safe Approach
S = Shout for help
A = Approach with care
F = Free from danger
E = Evaluated


Evaluated
1. Position (Sniffing) patency (look, listen, feeling)
2. Breathing
- Five initial rescue breath
a. mouth - mouth and nose
b. bag and mask
c. general guidence :
- the chest should rise
- inflation pressure may be higher
- slow breath at the lowest pressure gastric distention


Circulation
a. Assesment = feeling for the brachial or femoral pulse
b. If the pulse absent's = cardiac