HPRS 2300 Homework Electronic Submission dates: Chapter and Page numbers refer to the Text Book ( Hitner and Nagle 6 E) PLEASE NOTE: Check the Lesson Plan for the due dates. ALL SUBMISSIONS ARE DUE BY THE DATE LISTED HW ACITIVITY#1- Work on Chapter Review Sheets: Ch. 1- Pages 13-14 Understanding Terminology- items 1-7 1. The studey of the amount of drug that is required to produce therapeutic effects. – posology 2. The study of the harmful effects of drugs on living tissue. – Toxicology 3. The study of the action of drugs on living tissue.
– Pharmacodynamics 4. The study of drugs. – Pharmacology 5. The science of preparing and dispensing medicines. – Pharmacy 6. The study of the processes of drug absorption distribution, metabolism, and excretion. – Pharmacokinetics 7. The study of the use of drugs in treating disease. – Pharmacotherapeutics Answers- items 8-14 8. Define a drug – Any substance that, when administered to living organisms, produces a change in function. 9. Differentiate between: Therapeutic effect – The intended effect of the drug.
Side effect – unintended effects of the drug that arrent harmful. Toxic effect – unintended effect of the drug that is harmful or even deadly. 10. What is the difference between site of action and mechanism of action? The site of action is the location within the body where the drug exerts its effects and the mechanism of action is the process that explains how a drug produces its effects. 11. What is the relationship between ED50, LD50, and therapeutic index? ED50, effective dose 50, is the dose required to produce half the maximal effect of a drug.
LD50, lethal dose 50, referes to the dose that will kill 50% of the animals in a test where several animals are used to evaluate the effectiveness of a drug. Therapeutic index is used to estimate the relative safety of a drug and is represented by LD50 divided by ED50. 12. Explain the difference between a prescription drug, OTC drug, and a controlled substance. A prescription drug requires written or phone order from a liscensed provider Over the counter drugs do not require orders from a provider and can be purchsed freely.
Controlled substances are drugs that have potential for abuse. These drugs typically have street value because of their desirable efffects of addictive nature. The substances often require in person visits and more frequent prescriptions written for refills. 13. Explain the difference between idiosyncrasy and drug allergy. An idiosyncrasy is simply and unusual or unexpected response to a drug, while an alergy occurs when somone produces antibodies in response to a drug. A severe allergic reaction can be life threatening.
Write a short paragraph describing the terms; receptor site, binding, drug action, agonist, antagonist, and competitive antagonism. A receptor site is located on a protein ussually within the cell membrane. A drug will bind to a site on a protein according to its structure. After binding there can be two responses. An agonist causes the protein function to increase, while an antagonist will cause a decrease in the particular function of a protein. Competitive antagonism occurs when both agonist and antagonist drugs bind to the same receptor.
Acquiring Knowledge- items 3-5 3. What is a dose-response curve and what information is given by it? A dose response curve show the relation of a drugs dose to its response in the body. A dose curve may also indicate a maximum response. 4. What is the importance of a time-plasma drug concentration curve? How often would you estimate that a drug should be administered per day if the drug is eliminated in 4 hours? In 24 hours? A time-plasma drug concentration curve indicates the amount of drug present in bloodplasma over the course of time.
When there is not enough drug present in the plasma, it falls into the innefective drug range. Too much and it falls into the toxic drug range. Ideally you would want to maintain a level of drug in the blood plasm that falls within the therapeutic range. Assuming the curve is symmetrical, for a drug that is eliminated in 4 hours, I would estimate a person should take the drug every two hours, 12 times a day, and for a drug the is eliminated in 24 hours, I would estiamate taking the drug every 12 hours, two times a day. 5.
It is interesting that a drug can produce a therapeutic effect and an undesired side effect in one situation, and the same side effect may be consdered a therapeutic effect in another situation. Explain this phenomenon using the drug promethaznie as an example. This is called a contraindication. Promethazine is an antihistamine meant to reduce nausea and vommiting, but is also used in patients with central nervous system depression or a history of phenothiazine-induced jaundice. Ch. 2- Pages 30-31 Understanding Terminology- items 1-6 1.
When the combined effect of two drugs, each producing the same biological response by the same mechanism of action, is equal to the sum of their individual effects. – summation 2. When the combined effect of two drugs, each producing the same biological response but by a different mechanism of action, is equal to the sum of their effects. – additive effects 3. When the combined effect of two drugs is greater than the sum of their individual effects. – synergism 4. When the combined effect of two drugs is less than the sum of their individual effects.
– Antagonism 5. usually refers to physical alterations of drugs that occur before administration with different drugs are mixed in the same syringe or other container. – incompatibility 6. decreased drug effects after chronic administration. – tolerance Answers- items 7-16 7. Differentiate between the following terms: Parenteral administration – any route that does not involve the GI tract Oral administration -by mouth Intramuscular injection – injected into muscles such as the gluteus and deltoid Intravenous injection – injected directly into blood via vein. 8.
what is the main disadvantage to the IV method of drug administration? The drug can not be withdrawn once administered. 9. by what method of cell transport are most drugs absorbed? Filtration, passive and active transport. What are the main requirements for drug absorption? That the concentration of the drug differs on each side of the membrane. 10. explain why the alkalinization of the urine increases the rate of excretion of drugs such as aspirin or phenobarbital. In an alkaline solution, drugs such as aspirin are mostly ionized and are more rapidly excreted by acidifying the urine.
11. briefly describe the main factors that determine drug distribution. Plasma protein albumin, blood flow, presence of specific tissue barriers such as the blood brain barrier. 12. what is the main requirement for a drug it is to gain access to the brain? Lipid soluble 13. What is the drug microsomal metabolizing system, and what is its main function? Enzymes in the liver cytochrome p450 that converts drugs into their metabolites. 14. list the major pathways of drug excretion. Renal excretion, GI excretion, and respiratory excretion.
15. why is the plasma drug concentration important? What are the main factors that determine plasma concentration? The plasma drug concentration can determine if their is sufficient drug in the blood to provide a therapeutic effect. the main factors that determine this are Gi absorption how much of the drug bind to plasma protein, and metabolism. 16. list the factors that can contribute to individual variation in drug response. Age, weight, sex, genetics, emotional state, placebo effect, disease, and patient compliance.