pharmacology

Introduction to PharmacologyDrugs—chemical substances used or intended to be used to modify or explore the physiological condition or pathological state for the benefit of the recipient. Drugs may be used for prevention, diagnosis and treatment.
Major divisions of pharmacology—1. Pharmacokinetics.2. Pharmacodynamics.
Other divisions—1. Pharmacotherapeutics.2. Clinical pharmacology.3. Pharmacogenetics4. Immunopharmacology5. Pharmacognosy6. Toxicology7. Pharmacopoeia
Pharmacokinetics—(what the body does to the drug)—it is the branch of pharmacology that deals with drug dose, routes of administration and absorption, distribution, metabolism and excretion.
Pharmacodynamics—(what the drug does to the body)—it is a branch of pharmacology that deals with the mechanism of action, pharmacological effects, indication and contraindication of use and adverse effects of drugs.
Toxicology—it is the branch of pharmacology which deals with poisonous drugs, their source, properties, sign-symptoms they produce and management of poisoning.
Pharmacopoeia—it is a book published by authority of recognized body which contains list of drug, their properties, description, preparation and method of prescribing.
Pharmacogenetics—it is that branch of pharmacology which deals with genetic variations to the drug response.Ex—§ Isoniazide is an anti-tubercular drug which is metabolized by acetylation. If acetylation process is increased in that person for genetic factor then more drug is needed.§ Patients with glucose-6-phosphate dehydrogenase deficiency may produce haemolytic anaemia if anti-malarial drug is given
وأول ما يدرس فى علم الدواء هوا الفارماكوكيناتيك :Pharmacokinetics
Pharmacokinetics is the study of what the body does to a drug.
وما يفعله الجسم للدواء مند دخول الدواء للجسم الى حد الخروج منه هده المراحل تسمى الفارماكوكيناتك وتنقسم الى اربع مراحل وهى
1- absorption
2- distribution
3- metabolism
4- excretion
وهده المراحل الاربع تختصر بالحروف الاتيه ADME
A= absorption
D= distribution
M= metabolism
E= excretion

ولكل نقطه من النقاط السابقه عوامل تساعد وتأتر فيها ( ادا احب احد ان يعرفها اكتر يراسلنى )

Routes of Drug Administration:
1 entric rout وتشمل كل من الاتى
oral route rectal route sub-lingual route inhalation
ولكل من الطرق التى دكرناها ميزات وعيوب
2 parentral route وتشتمل علي كل من الاتى
topical route
a- eye , ear nose preparation ointment, drops ,
b- dermal preparation EX. creams,ointment,gel , massage and emulsion ......etc.
c- injections وهده بحد داتها تنقسم الى العديد من الانواع وندكر منها
intramuscular intravenous , subcotunus , intracardiac , intraarticular , intrabuccual ...........etc .
ملاحظة : لكل نوع من انواع طرق اعطاء الدواء ميزات وعيوب وهى مهمة جدا
نكمل بادن الله فى التعليقات التى فى الاسفل فى الايام القادمه

تعريفات مهمة :
The Volume of Distribution (Vd)[/b]
is the amount of drug in the body divided by the concentration in the blood. Drugs that are highly lipid soluble, such as digoxin, have a very high volume of distribution (500 litres). Drugs which are lipid insoluble, such as neuromuscular blockers, remain in the blood, and have a low Vd.

[b]The Clearance (Cl)
is the volume of plasma from which the drug is completely removed per unit time. The amount eliminated is proportional to the concentration of the drug in the blood.
bioavilability
This is the fraction of the administered dose that reaches the systemic circulation. Bioavailability is 100% for intravenous injection. It varies for other routes depending on incomplete absorption, first pass hepatic metabolism etc.
Drug distribution

Drug distribution refers to the movement of drug to and from the blood and various tissues of the body (for example, fat, muscle, and brain tissue) and the relative proportions of drug in the tissues.
Half-life (t ½)
The half-life is the time necessary for the concentration of drug in the plasma to decrease by half