Pharmacology in Radiological and Medical Imaging (Rad 355)

1. Pharmacology in Radiological and Medical Imaging (Rad 355) By Dr. Amr A. Abd-Elghany Assistant Professor, Collegue of Applied Medical Sciences aamoh_73@yahoo.com

2. Course plan • Basic concepts of pharmacology • Drug Classification • Routes of drug administration • General pharmacological principles • Five rights of drug safety • Drugs relevant to medical imaging • Contrast agents

3. Learning activities A) Lectures: the handouts for each lecture will be available to you on the day of the lecture. B) Study requirements: 1) Read the assigned material before class, 2) Attend all lectures and be on time, 3) Take notes and highlights as advised during the lecture, 4) Review your notes within 4 hours to transfer information into long term memory, 5) Reread the text within 8-12 hours and add additional information to notebook, 6) Become a part of the group learning discussion, 7) Come to my office hours for clarification of learning difficulties. C) Evaluation: Attendance and activities 10% First mid term 20% Second mid term 20% Final exam 50%

4. Basic concepts of pharmacology • Pharmacology: is a branch of science concerning the knowledge of: The history Source Physical and chemical properties Compounding Biochemical and physiological effects Mechanism of action Absorption Distribution Biotransformation Excretion Therapeutics and other uses Of drugs

5. A drug: is any chemical substance that produces a biological response in a living system. More specifically, a drug is a substance used as medicine to aid in the diagnosis, treatment, or prevention of disease. Different subjects that pharmacology deals with: The relationship between the dose of a drug given to the patient and the utility of that drug in treating the patient disease is described by two basic areas of pharmacology: Pharmacokinetics What the body does to the drug Pharmacodynamics What the drug does to the body And

6. Pharmacokineticsdeals with the absorption, biotransformation, and excretion of the drugs. • Pharmacodynamicsdeals with the study of the biochemical and physiological effects of drugs and their mechanisms of action. • Pharmacotherapeuticsdeals with the use of drugs in the prevention and treatment of disease. • Toxicologyis the aspect of pharmacology that deals with the diverse effects of drugs. It is concerned not only with drugs used in therapy but also with many other chemicals that may be responsible for household environment or industrial intoxication.

7. Absorptiondescribes the rate at which a drug leaves its site of administration. • Drugs given in aqueous solution are more readily absorbed than those given in oily solution, suspension, or solid form because they mix more readily with the aqueous phase at the absorptive site. • Bioavailabilityis a term used to indicate the extent to which a drug reaches its site of action or a biological fluid from which the drug has access to its site of action. • Bioavailability is decreased if the drug is metabolized in the liver or excreted in the bile.

8. Physicochemical factors in transfer of drugs across membranes • The absorption, distribution, biotransformation, and excretion of a drug all involve its passage across cell membranes.

9. Diffusion One of the different mechanisms of drug transfer is the movement of small molecules from an area of higher concentration to an area of lower concentration. It is the simplest type of passive transport. The difference in concentration of molecules across a space is called a concentration gradient The rate of diffusion depends on Type of the molecule Temperature size

10. Diffusion of molecules across the membrane occurs down its concentration gradient

11. Types of membrane transport Active transport e.g. Na-K pump Passive transport e.g. water, O2, CO2 Facilitated diffusion e.g. Gulcose transport

12. Facilitated diffusion e.g. Gulcose transport Uses carrier proteins Sometimes called ion channels Some ion channels are: Open Others Have Gates Three kind of stimuli that may open or close the gates 1.Stretching of the cell membrane 2.Electrical signals 3. Chemicals in the cytosol or External environment.

13. Osmosis It is the diffusion of water across the cell membrane from an area of higher Concentration to an area of lower concentration.

14. In animal cells shrinkage In plant cells plasmolysis In animal cells Cytolysis In plant cells Turgor pressure