1 st week

• Absorption refers to the process whereby a drug enters the bloodstream from its site of administration.
• The four stages of pharmacokinetics include absorption, distribution, metabolism, and elimination.
• To affect in targetted organ→take minimum theurapeutical dose
• passive diffusion is the movement of molecules from a region of high concentration to a region of low concentration with no energy and transporter protein using
• facilitated diffusion is the movement of molecules across a membrane from a region of high concentration to a region of low concentration by using transporter protein but no energy using
• active transport is the movement of molecules from a low concentration to a high concentration across a cell membrane against a concentration gradient with transporter protein and energy
• active transport is zero degree kinetics and passive diffusion is first degree kinetics
• In active transport concentration decreases saturation dissapears
• uniport is a single molecule is transported by transporter protein
• co-transport is the movement of ions across the membrane in a coupled reaction with same direction
• contra transport is two or more molecules moving in opposite directions in the same route
• pinocytosis: the ingestion of high concentrated molecule into a cell by the budding of small vesicles from the cell membrane.
• phagocytosis is similar to pinocytosis but only occurs in macrophages and neutrophils
• receptor mediated endocytosis is similar to pinocytosis but large molecules enter the cell by binding to receptors on the cell surface
• examples of receptor mediated endocytosis is taking hormones and proteins into the cell
• First pass elimination is the process by which a drug is absorbed in GI mucosa then pass into the portal system from mucsal capillaries

  First pass elimination is metabolized and excreted in the liver
• CYP4503A4 isoenzyme is used for metaboism of first pass elimination
• prevent from first pass elimination is administer the drug in parenteral instead of oral route
• In steady state concentration absorption =metabolism =excretion
• before reaching steady state concentration absorption is higher then metabolism and excretion
• after steady state concertration metabolism and excretion are higher than absorption
• In enterohepatic cyclus some drugs enter into system other ones are excreted by bile which all are absorbed in intestinal lumen and metabolized by liver with CYP4503A4
• enterohepatic cyclus is recognized by gluchromate and sulphate conjugates which are excreted by bile and broken down by beta gluchloridase and sulphatase
• conjugates can't absorbed by intestines while free drug molecules can
• prodrugs are not active firstly but are activated when they enters the body
• • prodrugs increases solubility and absorption of a drug
  • prevent the bereakdown of a drug in GI tract
  • mask the bad taste and smell of a drug
• Intranasal route

  infections of nasal mucosa and paranasal sinus disease

  Local effect
• Superficial inflammation and other diseases in oral gingiva

  Buccal route
• Antaacids and MgSO4 like laxatives

  Local effect
• Example on laxatives and antaacids

  Rennie

  Gaviscon
• Intrathecal route


  Injection of a drug to subaranchoid space

  between 3rd and 4th lumbar vertabrae
• Pleural and peritoneal infections and tumors

  Intraperitoneal and intrapleural routes
• Intraperitoneal and intrapleural routes

  Local effect with special injectors
• Intrauterine device is placed to intrauterine space→provide contraception
• Example of intrauterine route is after c section oxytocin was given in that route
• Intraarticular

  Cartilage
• Rectum and colon routesystemic effect

  Antipyretics
• Rectum and colon route local effect

  Hemorrhoid

  anal fissure

  polyp

  contrast agent into the colon
• Lesion route

  Superficial tumoral and inflammative lesions
• Application of lesion route

  Directly on lesion