pharm 3.1/3.2- lytes and kinetics interact

hyperkalemia treatment

based on cause; restrict K intake or adjust diuretics, severe cases can use SPS (Kayexalate) or patiromer to eliminate potassium in the stool

SPS

(sodium polystyrene sulfonate) aka Kayexalate, can be given PO or an an enema, exchanges sodium ions for potassium in the bowels to eliminate potassium in stool and lower K levels

patiromer

PO, binds to excess K in GI tract to be eliminated in bowels

leading cause of hyperkalemia

kidney disease

leading cause of hypokalemia

severe electrolyte loss (vomiting, diarrhea, diuretics)

lymph

liquid portion of blood in lymph vessels

serum vs plasma

serum= liquid in blood after a clot, plasma= liquid of blood with no clotting factors

hypokalemia treatment

potassium replacement, PO or IVF/ IVPB,

PO KCl

given for mild hypokalemia or as preventative measure, or to people on diuretics, no need to double check= not high alert

IVF potassium

always 1L bag, always on pump, no double check if pharmacist makes bag, hang bags until order is discontinued

IVPB potassium

always on pump, pump at 100ml/hour max= 10 Meq/hour of K,

IVP potassium

cannot be given this way! = lethal injection, heart would stop

no pee no K

means you cannot give potassium if there is no urine output, no way to dispense of excess

correct salt substitue

Ms Dash, others can have high potassium instead of sodium

side effects of PO KCl

can be hard on GI tract causing irritation, can cause hyperkalemia

nursing implications of K

moniter levels and UOP, never give SQ or IM, high alert for IVF and IVPB, max rate for IV KCl is 10meq /hour

why monitor UOP after giving potassium

due to high chance of contraindication with renal failure

patient education of K

do not crush ER or EC oral potassium, take with food to prevent GI pain, capsules can be opened and mixed with food, powder/liquid can be mixed with water

red flag of IV potassium

pain or burning at IV site, can be too fast of an infusion

mild hypernatremia treatment

restrict sodium intake

hypernatremia treatment with hypovolemia

hypotonic fluids to increase fluid to solute ratio

hypernatremia treatment with hypervolemia

diuretics to remove water+ sodium together, and give IV fluids to replace later

hyponatremia treatment from fluid overload

fluid restriction or loop diuretics

hyponatremia treatment from Na loss

replace sodium orally with gatorade to pedialyte

severe hyponatremia treatment

hypertonic IV solution

nursing implications with sodium levels

moniter I&O every shift, signs for low and high sodium, CNP and BNP levels

r/t

related to

pharmo

medicine

kinetics

movement

pharmakinetics

how drugs move in the body

ADME- pharmacokinetics

absorption, distribution, metabolism, excretion

absorption

movement of drugs in body fluid and across cells and cell membranes, aligned with course of action, route determined the speed (IV is fastest)

common sites of absorption

stomach and lining go small intestine, respiratory, vaginal, rectal, and all other mucous membranes

things that can effect absorption

function of GI tract, food consumed prior to medication in Gi tract

onset of action

amount of time it takes for a drug to start working

duration of action

full amount of time from onset to elimination

peak action

when a drug exerts maximum effect

bioavailability

portion of drug able produce a systemic effect, differences can change how a drug acts

fastest route for a drug

IV

fastest to slowest drug routes

IV, SQ and IM, SL, rectal, and inhalation, skin and oral are slowest

formulation of drugs effect on absorption

some drugs can have delayed absorption causing a delayed action like EC, LA , XR drugs

distribution of drugs

movement of drugs throughout the body

conditions associated with distribution

anything that impairs blood flow can impair distribution (vasoconstriction, ischemia)

blood flow affect on distribution

more blood flow= greater drug supply, shock is decreased cardiac flow so this can lessen distribution,

tissues that have less drug distribution

bone and adipose tissue due to lower blood supply

barriers affect on distribution

can slow distribution due to limited blood flow, like blood brain barrier and placenta

protein binding affect on distribution

many drugs partially bind to albumin and travel through the blood, bonded portion is inactive and free portion produced effect

low albumin effect on distribution

can cause risk for drug toxicity, due to less of the drug binding with albumin and more being avalible to produce a response

metabolism

how a drug is broken down into something that can be eliminated from the body

biotranformation

transforming drugs to be eliminated

primary place for metabolism

liver

hepatic P-450 enzyme system

enzyme inactivates drugs and enhances their excretion, major pathway for metabolism of drugs

inducer of P-450 system

cause drugs to be eliminated quicker

inhibitor of P-450 system

prevents drugs from being metabolized in the normal amount of time, extends duration of action

first- pass effect

the metabolism that occurs in the liver which begins the breakdown, if a drug is 100% metabolized first pass than it cannot be given PO

conjugates

metabolized drugs

routes that bypass first pass effect

sublingual, buccal, opthalmic, rectal, vaginal, inhalation, IV (anything that is not swallowed)

excretion

how the drug leaves the body

main organ in excretion of drugs

kidneys

kidney role in excretion

gloumular filtration causes things to be directly excreted in the urine, can be active or passive movement into the tubule

renal failure role effect excretion

drugs will remain in circulation for longer

2 populations most at risk for impaired excretion

elderly and newborns

respiratory role in excretion

if drug is converted to gaseous waste

glandular role in excretion

can be waste in form of sweat or mammary glands

bile role in excretion

portion of bile in small intestine gets reabsorbed many times which causes a drug to circulate for longer

changes in Gi tract can affect

absorption, distribution, metabolism or excretion

plasma half life

time that it takes to for the body to eliminate half of the administered dose

frequency of a drug is determined by

plasma half life and duration of action

steady state

when a drug has reached the therapeutic range, amount of drug taken= amount eliminated from the body

loading dose

initial larger dose to achieve therapeutic range faster, if you cannot wait for doses to build up in a steady state

maintenance doses

smaller doses given more frequently to maintain therapeutic range of concentration in blood

types of drug interactions

indifferent, additive, synergistic (potentiate) competing for binds sites, or metabolic inducers

indifferent drugs

neither has an effect on each other

additive drugs

two drugs taken together than improve performance in an expected way (1+1=2)

potentiate drugs

when two drugs from different classes taken together produce a greater than expected response

syngerism

when 2 drugs from the same class are used together to produce a big response

competition of drug binding sites

when one drug has a higher affinity and beats another drug for binding sites, more likely a toxicity in the drug with lower affinity

CYP-450 inducers

increase activity of P-450 enzymes, drugs are eliminated faster and patients may need more than original dose

CYP-450 inhibitors

prevent the metabolism of of drugs and allow for them to be in the body for longer creating a longer effect