pharmocology Flashcards
(36 cards)
pharmacodynamics
drug effect on the body
pharmacokinetic
bodies effect no the drug
frugs derived from
plants, animals, synthesis in lab, microorganism and minerals
drug name
chemical name- the chemical composition of the drug and identifies the drugs atomic and molecular structure
generic name- abbreviated and approved name
trade name- brand name selected by the drug company
enteral route
oral-
person swallowing which is absorbed by the GI tract goes to first pass metabolism
adv. pain free, non invasive, cost less
disadv. requires compliance, conscious and cooperative, longer
sublingual and buccal
facilitate rapid absorption of medication via capillaries of the mucous membrane
avoid 1st pass metabolism
parenteral route
non oral method of drug administration
adv. oral drug not effective, patient cooperation and compliance, avoids first pass metabolism
disadv. skill required, painful and expensive
pulmonary route
administered by gas or fine mist.
lungs provide large SA for absorption. Their adjacent rich capillary network allows drugs to readily enter the circulation
topical route
drugs to the skin or mucous membrane
pharmacokinetics
absorption
moves from site of administration to the systemic circulation
IV administration enters directly into systemic circulation
oral medication:
disintegrate
dissolution
absorbed by small intestine
hepatic portal system( blood supply to liver)
systemic circulation
factors of drug absorption
formulation of drug route of administration tissue SA and thickness blood supply at site of administration solubility of drug
pharmacokinetics distribution
movement of drug to body tissues depend on:
drug solubility, cardiovascular functioning, perfusion of area, pH of area, binding of the drug to plasma protein, tissue binding
tissue adipose
lipid soluble drugs have a high affinity for drug adipose tissue. Low blood flow to this tissue means some drugs may be stored here
bone tissue
special affinity for bone and can accumulate here
barriers to drug distribution
blood brain barrier- endothelial cells with tight intercellular junctions to protect CNS from potentially damaging microorganism and other substances
placental barrier- membrane and enzymes providing incomplete protection to fatal circulation
metabolism
drugs are broken down into substances more easily eliminated
factors affecting metabolism:
genetics, environmental factors, age, gender, disease states
bioavailability
amount of drug that is available to exert a pharmacological effect
the proportion of drug that reaches the systemic circulation
oral drugs have low bioavailability
hepatic first pass metabolism means oral dose of a medication is often higher than would be given IV
hepatic first pass metabolism
oral drugs pass through GI tract before absorbed through GI mucosa into the blood of the surrounding capillaries.
some drugs may be lost if not absorbed from the GI tract
make it way from capillaries into the hepatic portal vein for transport to the liver
drug reaching the liver undergo metabolism before reaching the systemic circulation. (first pass metabolism)
excretion
elimination (liver)- irreversible loss of the drug from the plasma. occurs via metabolism and excretion
excretion (kidneys)- irreversible loss of the drug from the body
eliminated in bile so removed from the body faeces
free unbound drug can be filtered from the blood into the renal filtrate
lipid soluble drugs may be reabsorbed from the renal filtrate back into the systemic circulation
water soluble drugs can also be secreted from the blood into filtrate
therapeutic range
concentration of drug having a high probability pf producing the desired therapeutic effect and low probability of toxic effects
minimum effective concentration- amount of drug required to cause a pharmacological effect
minimum toxic concentration- min amount drug that causes a toxic effect
drug half life
time taken for the drug concentration to be reduced by 50% from its max concentration
it tells us how quickly drug is being eliminated from plasma and how often we need to administer a drug to keep it within the therapeutic range
the mode of drug action depends on the drug’s molecular target
carrier proteins, ion channels, enzymes and receptors
carrier proteins
drugs alter function of carrier protein or bind to prevent carrier protein from moving molecules into the cell