5 Written Questions
5 Matching Questions
- protein binding
- class I vs class II drugs
- Volume of distribution
- t 1/2
- a 2/3 in intracellular compartment and 1/3 in extracellular compartment (between cells). Drugs can distrib into any of these compartments dep on size and hydrophobicity of drug. (V(d)=Total amt of drug in body/plasma concentration of drug-->Know: small V(d) indicates drug is primarily sequestered in plasma, a Large V(d) indicates that relatively little of the drug stays in plasma (if mroe than one, more disrib in body and less in bloodstream if less than one, less in body and more in bloodstream, if 1-equal)
- b area under the curve: overall exposure to drug over time.
- c clas I: drugs where the dose is less than albumin's capacity to bind (when administered, there will be excess albumin for further binding). class II:given in doses much greater than albumin's ability to bind to it (means there is much more of the drug left over, causing lots of the drug to be free and not to be bound to albumin). if you combine a class I with a class II, free drugs levels of Class I will be much higher, potentially dangerous and may cause overdose situation. Free drugs are active, bound drugs are inert)
- d most drugs reversibly bind to plasma proteins. drugs bound to albumin is going to be inactive. albumin is the most common protein in the plasma, albumin keeps blood within the blood vessels. As plasma concentration of the drug increases, more binding occurs.
- e time for drug concentration to fall by half
5 Multiple Choice Questions
- a. first pass hepatic metabolism: first pass metabolism refers to drugs entering hepatic portal system from intestines, b. drug solubility: very hydrophilic or hydrophobic drugs have difficulty crossing cell membranes and entering most drugs prefer to be hydrophobic and a little hydrophilic so they can pass cell membranes easily., c. chemical instability: some drugs may be affected by stomach's pH or various degradative enzymes in GI tract., d. chemicophysical properties of the drug(suzem salt form)
- can easily get out of blood stream
- physiochemical makeup helps determine how easy or difficult drug passes thru membranes (concentration gradient, how lipophilic and surface area of cell)
- a)enteric coated allows drug to pass thru stomach without being destroyed by gastric acid. b)controlled release preparation allows drug to release a uniform stream to absorption site over relatively long period of time (disadvantages of this include differences between patients, failure of controlled release causing dose dumping or reduced drug release)other forms of enteral administration
- inhalation, intranasal, topical, transdermal (nicotine patches)
5 True/False Questions
absorption → rate and extent that the drugs leaves site of administration. a)how long it takes for an oral drug to enter bloodstream from small intestine and how much of the drug makes it. b. bioavailability: [how much of a drug makes it into the bloodstream] what fraction of the dose of a drug reaches its site of actino or a body fluid where the drug has accss to its action.
distribution. → the prcoess thru which the drug leaves the bloods tream and enters interstitium (absorption is about intestines, distrib is about bloodstream). 4 aspects: blood flow, capillary permeability, drug structure, degree of binding to proteins
administration of drugs → determine how readily crosses membrane. uncharged chemicals more easily pass membranes. weak acids and bases can be charged or uncharged, but each drug's charge changes based on interaction with body's pH
cons of oral/enteral administration → (sublingual allows drug to bypass intestines and liver preventing first pass metabolism), rectal(only 50 % of drug enters the liver and is metabolism. disadvantages include irregular and incomplete absorption and irritation of the rectal mucosa)
facilitated diffusion → no atp. carrier protein assists drug in entering cell