pharm midterm 1

right client, right drug, right route, right documentation, right assessment, right to education

estimates the margin of safety of a drug through the use of ration that measures the effective dose in 50% of people and the lethal dose of 50%

ti=ld/ed

• highest plasma concentration of drug at a specific time 
• indicate rate of absorption

• indicate the lowest plasma concentration of a drug 
• measures rate of elimination
• nurse implication- drawn immediately before next dose

large initial dose to achieve rapid minimum effective concentration in the plasma

the time it takes for one half of the drug concentration to be eliminated

is the percentage  of the administered drug dose that reaches the systemic circulation

drug administration by oral route and absorbed via the GI tract undergo some metabolism in the hepatocytes in the liver before they are made available to the body tissue

nursing implication-effects clients that have hepatic medical problems or if client is taking drugs that also pass through liver

study of the time course of drug absorption, distribution,metabolism and excretion

movement of drug particles  from the GI tract to body fluids by passive absorption, active absorption, pinocytosis. 

• most drugs are absorbed into the surface area of the small intestines thru action of the extensive mucosal villi. absorption is reduced if the villa are decreased 
• causes of decrease vill can be disease, drug effect or removal of the small intestines
• protein based drugs such as insulin and growth hormones are destroyed in the small intestines  by digestive enzyme
• degree and rate of absorption are based on factors such as the childs age healthstatus and weight and route of admin

• occurs mostly by diffusion by movement of higher concentration to lower concentration
• does not require energy to move across the membrane

• requires a carrier such as an enzyme or protein to the drug against  a concentration gradient
• energy is required

process by which cells carry a drug across their membrane by engulfing the drug

drugs that are lipid soluble pass rapidly thru the GI membrane

a carrier, either enzyme or protein to pass thru membrane

nonionized have no positive or negative charge

• is a weak acid drug 
• is less ionized in the stomach and passes thru stomach lining easily and rapidly

• have a higher PH than adults 
• infants can absorb can absorb more penicillin

• pain stress, hunger fasting, blood flow , food and PH 
• foods that are solid hot or high in fat can slow gastric emptying so drug remain in stomach longer

• process by which the drug becomes available to body fluids and body tissue
• affected by body fluid, body composition, body tissue composition and protein binding
• until age 2 pediatric pts require higher dose of water soluble meds
• neonates have less albumin and fewer protein receptor sites available
• infants bbb are immature and allow medication to pass easily into nervous system  and increase toxicity

process by which the body becomes inactivates or biotransforms drugs

• liver is primary site with lung and kidney playng small part
• most drugs are inactivated  by liver enzymes and are then converted to hepatic enzymes
• large % of drugs are lipid soluble, thus the liver metabolizes the lipid soluble drug substance to water soluble substance for renal excretion
• liver disease such as cirrhosis and hepatitis alter drug metabolism in decreased excess drug accumulation can occur and lead to toxicity
• children less than 2 sustain decreased level of hepatic enzyme which result in slower metabolism of medication
• children have higher metabolic rate than adults

• elimination thru kidneys 
• other routes include bile feces lungs saliva sweat and breast milk
• kidneys filter free unbound drugs water soluble and drugs that are unchanged
• lungs eliminate volatile  drug substances and products metabolized to co2 and h2o
• acidic urine promotes elimination of weak base drugs
• alkaline urine promotes elimination of weak acid drugs

refers to action and effect of a drug on the body and includes the onset ,peak and duration of effect of medication

relationship between the minimal versus the maximal amount of drug does needed to produce the desired drug response

• all drugs have a max drug effect
• the ma efficacy of morphine is higher than tramadol no matter how much tramadol is given

time it takes to reach the minimum effective concentration after drug is administered

occurs when the drug reaches it highest blood or plasma concentration

length of time the drug has a pharmacologic effect

• gastric ph is alkaline at birth 
• acid production begins at neonatal period
• gastric ph reaches adult acidity at 1-3 years
• a low ph or acidic environment favors acidic drug absorption
• a high ph or alkaline environment favor basic drug formulation
• gastric emptying is prolonged in neonates but increases as child grows
• nurses should be aware that delayed emptying in children reduces the peak serum concentration of meds
• lack of maturation of the gi tract is most pronounced in infancy, making the neonatal and infancy periods those most affected by changes in absorption

gi surface area is greater than in adults allowing for more absorptive area in the stomach and intestine

• breast fed infants have faster gastric emptying than formula fed infants 
• the more frequent feedings the less time food is in contact with gastric or intestinal linning

• absorption occurs in the tissues
• the level of peripheral perfusion and effectiveness of circulation affects the meds ability to be absorbed
•  conditions that alter perfusion is dehydration, cold temp, alterations in cardiac status

• absorption is enhanced because skin is thinner and more porous
• topicals can be altered by skin conditions

• 70% water
• increased body fluid proportion allows for greater volume of fluid in which to dispute meds and lower concentration of drugs
• until 2 children require higher doses of water soluble meds to achieve therapeutic levels
• younger pt's have higher levels of EF which increase the tendency for children to become dehydrated and change the distribution of water soluble meds

• neonates and younger children have less body fat
• this group requires less fat soluble meds than adults
• fat soluble meds saturate fat tissue before acting on body tissue, less available saturation creates a need for less meds

• drugs become bound to circulating plasma proteins in the body
• only drugs that are free, or unbound are available to cross the cell membrane and exert an effect
• infants have less albumin and fewer protein receptor sites  available for binding  with meds ,this allows to be more available for use and dictates a decrease in dosage  needed in young pts  to produce therapeutic effect
• greater amount of circulating drugs caused by reduced plasma proteins increase toxic reactions in infants less than 1
• bilirubin molecules may bind w/plasma protein sites making sites unavailable to meds and allowing large amounts of drug to remain free and available for effect

• jaundice
• hyperbillirubinenmia

infants bbb are immature and allow meds to pass easily through nervous system tissue and increase likelihood of toxicity

• carried out primarily in the liver with kidney and lungs playing a small part
• children under 2 have decreased levels of hepatic enzyme resulting in slower metabolism
• hepatic metabolic activity is lower in neonates
• hepatic function matures at age 1-2 months

• children have higher metabolic rates causes metabolism to occur more rapidly this may facilitate a higher med requirement
• pain meds in children may require increased dosages or decrease duration between dosages

• before age 9 mths reduction in elimination capacity of the kidneys due to decreased renal blood flow 
• decreased glomular filtration rate and reduced renal tubular function 
• decreases in renal tubular function occurs in adolescence which causes meds to be excreted slower

can be added to jelly or honey if older than1

deliver therapeutic care through interventions that eliminate or minimize the psychological and physical distress experienced by children and their family

eutectic mixture of local anesthetics a topical cream, anesthetizes the site of injection if applied 1-2.5 hours before injection

not recommended in children use

body weight and body surface area