8/14/2019 Pharma 04

1/6

ONIVERSIlYOf JORDAN '?'Faculty OFMedicine , .-----

oU ?-_ ~ M I . 1 I I ~ . t { A I J $ A I f '

8/14/2019 Pharma 04

2/6

By the name of allah**Type of receptors:We have 4 types of receptors in every human body.Receptor: kind of protein among the target and the drug.1. ligand-gated ion channel:Ligand means agonistIn this case the interaction between the drugs (agonist) andreceptor causes opening of ion channel.e.g:1. Nicotinic receptor2. Acetyl choline receptorLocation: nervous systemEffect: within milliseconds

2. G-protein coupled receptorsInitiate effects through activation of guanine nucleotide bindingproteinGTP-7 GDP -7 Adenylate cyclase -7 ATP -7 cyclic AMP (2ndmessenger)Kinases -7 protein phosphorylatione.g:1. muscarinic receptors2. acetyl choline receptors3. B- adrenoreceptorsLocation: cell membraneEffect: within secondsB-adrenoreceptors: leads to glycogen and fat metabolism in liver,fat and muscle cells3. Kinase-like receptorsIt causes -7 protein phosphorylation -7 Genes transcription -7protein synthesis -7 cellular effects

1

8/14/2019 Pharma 04

3/6

So its action becomes clear after few hourse.g: insulin, growth factors, cytokines receptors4. Nuclear receptorsLocation: cytoplasm or in nucleusEffect: after dayse.g: steroid receptorsdrugs that don't fit the drug-receptor modal (drugs don't actthrough receptors)the kind of drugs react with their targetsuch as:1. osmotic diruretic2. antacids which give to patient suffering from acidity, in this casethe interaction between acid (mainly HCI) and alkaline (base)directly without receptors.The biological Targets could be:1. Ion channel in our body (e.g: Na+ channel)2. enzymesHuman body full of enzymes that react with certain type of drugs3. macromolecules (e.g: DNA, RNA and special proteins)The interaction between the drug and DNA cause mutation in thecell.4. cell membrane carriers:Certain drugs can't enter the cell without interation with carriers incell membrane.Pharmacokinetics:The action of human body on the drugs (unlikepharmacodynamics)

8/14/2019 Pharma 04

4/6

Co: concentration reaction outsideCi: concentration reaction insideT: timeAs we see all these factors affecting affecting absorptionADVICE:Don't sit beside a smoker, because in milliseconds the smoke willgo from lungs to blood (this occur rapidly because large area

of absorption)Drugs classified to:1. weak acidic drugs (such as aspirin)pKa= 3.5suppose it carries a negative chargepKa is calculated by:pKa= pH + Log (concentration ofunionized molecules/ cone ofionized m)increase in ionization decrease in absorption increases clearly, theabsorption increases when the unionized concentration increase.2. weak basic drugs (such as Diazepam)Suppose to carry positive charge (pKa- 3.3)Calculated by:pKa = pH + log (cone of ionized! cone of unionized)3. neutral drugs (don't carry any charge)Mechanism of drug transport across membranes1. passive diffusion ,

8/14/2019 Pharma 04

5/6

Process ofpharmakinetics, for example:1. absorption2. distribution3. metabolism4. eliminationN.B: the same drugs could be in many forms so at certain time ofillness, we give certain form (depends on worsening)1. drug absorptionThe passage of the drug from it's site of administration in to theblood except LV. application (because it gives to blood directly sothere is no absorption)Cell membrane:It is a barrier that face the entery of drugs from outside to insidethe cell.Biomolecular lipid layer (so the drugs suppose to be lipid soluble,unionized and small in size) we can test if the drug can cross cellmembrane or not by buffer with HCl or acetate and shake it thiswill give colored drug then we observe if the drug goes to HCllayer ofwater layerIf it goes to HCllayer so it can pass lipid layer.We can use other organic solvent like octanol with buffer whichwe called lipid water portion coefficient value which indicate lipidsolubility of drugsAbsorption rate depends on Fick's law'"M= PA (Co - Ci) TWM: amount of uncharged moleculeA: area of cell membrane ( very important, that's why absorptionoccurs in intestine more than ~ b s o r p t i o n occurs in stomach)P: permeability

8/14/2019 Pharma 04

6/6

2. filtrationDepend on size ofmolecule (small enough to cross the pores)Driven by gradient pressureI want to dedicate this sheet to all my colleagues.

Zydon khrissat

, .