What is Pharmacology? • Name of faculty member responsible for the course: • Dr.AmiraBadr • Dr.NajlaaAl.Orabi • Dr.NayiraAbdulbaqy
Syllbus • Summary of the main learning outcomes for students enrolled in the course. • To be familiar to the scope of pharmacology, common drug uses, their sources and routes of administration. • To understand the basis of drug actions , drug pharmacokinetics and pharmacodynamics, receptor types drug-receptor interaction, and common adverse effects of drugs. • To identify the different classes of drugs affecting the two main divisions of the autonomic nervous system (sympathetic and parasympsathatic).
To identify the effectct and therapeutic uses of different class of autonomic drugs. • To discuss side effects and contraindication of commonly used autonomic drugs • To identify the various classes of cardiovascular affecting drugs; antihypertensives and antiarrhythmic drugs • To identify various cardiovascular diseases, and drug classes use in management of each disease. • To explain the major pharmacological actions of different autocoids in the body.
EvaluationD/amira: • Midterm: 7marks • Quiz on week 4: 2 marks • File (4 stunts) : 2 marks تنبيهات: • لا يتجاوز الغياب 6 محاضرات على مدار الترم. • الغياب عن الquizz لا بد أن يكو بعزر مسبق. • يتم تسليم النشاط فى الوقت المحدد والا لن يعتد به. • التغيب عن الامتحان الفصلى لا بد أن يرفق بشهادة مرضية مختومة من جهة حكومية.
What is Pharmacology? • derived from the Greek word for drug • A science that studies drug effects within a living system, biochemical and physiological aspects • Deals with all drugs used in society today, legal or illegal, including street, prescription, and non-prescription or over –the-counter medications
Drug • A drug is defined as any substance; chemical agent; used in the • Diagnosis • Cure • Treatment • prevention of a disease or condition
Drug Names • Chemical Name • Generic Name • Trade Name
Chemical Name • Describes its molecular structure and distinguishes it from other drugs
Generic name • Determined by the pharmaceutical company along with a special organization known as the U.S. Adopted Names Council (USAN)
Trade Name • Or brand name- the manufacturer selects alone…can become a registered trademark. • They are the only one who can advertise and market the drug under that name.
How is the Trade Name Chosen? • The particular spelling of a brand name drug is proposed by a manufacturer for one of several reasons.
1. To indicate the disease process being treated • Azmacort- treats asthma • Rythmol- treats cardiac arrhythmias
2. To simplify the generic name • Pseudoephedrine to Sudefed • Haloperidol to Haldol • Ciprofloxacin to Cipro
3. To indicate the duration • Slow-K slow release potassium supplement
Prescription Drugs • Or legend drugs • Means in order to obtain drug, you must have a legal prescription
Non-Prescription Drugs • Or Over-the-Counter (OTC) drugs • Drug that may be purchased without a prescription
Sources of Drugs Drugs have been identified or derived from four main sources: • Plants • Animals • Minerals and Mineral Products • Synthetic or Chemical Substances Made in the Laboratory
Important Info Routes of Drug Administration The route of administration (ROA) that is chosen may have a profound effect upon the speed and efficiency with which the drug acts
The main routes of drug entry into the body may be divided into two classes: • Enteral • Parenteral
Enteral Routes • Enteral- drug placed directly in the GI tract: • sublingual - placed under the tongue • oral - swallowing (p.o., per os) • rectum - Absorption through the rectum
Sublingual/Buccal Some drugs are taken as smaller tablets which are held in the mouth or under the tongue. • Advantages • rapid absorption • drug stability • avoid first-pass effect
Sublingual/Buccal • Disadvantages • inconvenient • small doses • unpleasant taste of some drugs
Oral • Disadvantages • Sometimes inefficient - only part of the drug may be absorbed • First-pass effect - drugs absorbed orally are initially transported to the liver via the portal vein • irritation to gastric mucosa - nausea and vomiting
Oral • Disadvantages • destruction of drugs by gastric acid and digestive juices • effect too slow for emergencies • unpleasant taste of some drugs • unable to use in unconscious patient
First-pass Effect • The first-pass effect is the term used for the hepatic metabolism of a pharmacological agent when it is absorbed from the gut and delivered to the liver via the portal circulation. • The greater the first-pass effect, the less the agent will reach the systemic circulation when the agent is administered orally
First-pass Effect Magnitude of first pass hepatic effect:Extraction ratio (ER) ER = CL liver * Q ; where Q is hepatic blood flow (usually about 90 L per hour. Systemic drug bioavailability (F) may be determined from the extent of absorption (f) and the extraction ratio (ER): F = f x (1 -ER)
RECTAL ADMINISTRATION: • Absorption across the rectal mucosa occurs by passive diffusion. • This route of administration is useful in children, old people and unconscious patients. • Eg., drugs that administered are: aspirin, acetaminophen, theophylline, indomethacin, promethazine & certain barbiturates. KLECOP, Nipani
Rectal Advantages: Suitable for unconscious patients and children 2. suitable if patient is nauseous or vomiting 3. easy to terminate exposure 4. good for drugs affecting the bowel such as laxatives Disadvantages: absorption may be variable irritating drugs contraindicated
Parenteral Routes • Intravascular (IV, IA)- placing a drug directly into the blood stream • Intramuscular (IM) - drug injected into skeletal muscle • Subcutaneous- Absorption of drugs from the subcutaneous tissues • Intrathecal : into CSF
Intravascular Absorption phase is bypassed (100% bioavailability) 1.precise, accurate and almost immediate onset of action, 2. large quantities can be given, fairly pain free Disadvantages a-. greater risk of adverse effects b-high concentration attained rapidly C- risk of embolism
Intramuscular 1. very rapid absorption of drugs in aqueous solution 2. Slow release preparations Disadvantages pain at injection sites for certain drugs
Subcutaneous slow and constant absorption 2. absorption is limited by blood flow, affected if circulatory problems exist 3. concurrent administration of vasoconstrictor will slow absorption
Inhalation 1. gaseous and volatile agents and aerosols 2. rapid onset of action due to rapid access to circulation a. large surface area b. thin membranes separates alveoli from circulation c. high blood flow
Topical • Mucosal membranes (eye drops, antiseptic) • Skin • a. Dermal - rubbing in of oil or ointment (local action, sun screen, an callus removal) • b. Transdermal - absorption of drug through skin (systemic action) • i. stable blood levels • ii. no first pass metabolism • iii. drug must be potent or patch becomes too large
Intra nasal administration • Drugs generally administered by intra nasal route for treatment of local condition such as perennial rhinitis, allergic rhinitis and nasal decongestion etc.
Route for administration -Time until effect- • intravenous 30-60 seconds • intraosseous 30-60 seconds • endotracheal 2-3 minutes • inhalation 2-3 minutes • sublingual 3-5 minutes • intramuscular 11-30 minutes • subcutaneous 14-30 minutes • rectal 5-30 minutes • ingestion 30-90 minutes • transdermal (topical) variable (minutes to hours)
Aspects of Drug Pharmacokinetics (ADME) Drug at site of administration Absorption Drug in plasma Distribution Drug/metabolites in tissues Metabolism Elimination Drug/metabolites in urine, feces, bile