Routes of Drug Administration: Practical Revision

Practical Revision First year Module 108 Medical Pharmacology Department Faculty of Medicine 2022-2023 Practical Revision First year Module 108 Under the supervision of Prof. Omayma Khorshid Head of Medical Pharmacology Department Routes of administration Enteral Oral Sublingual Others Rectal Parenteral Injection Inhalation SC implantation Topical What is the route of administration of these dosage forms? Oral Mention the advantages of this route of administration. Easy. Safe. Economic. 2-Mention the disadvantages of this route of administration. 1-not used in Emergency situations (delayed onset): Patient: not used in 2- Uncooperative patients: comatosed, psychotics, infants & children. 3- In vomiting or severe diarrhea. Drug: not used 4- for highly irritant drugs (as emetine HCl). 5- Poorly absorbable drugs: when systemic effect is needed as in aminoglycosides. 6- Some drugs undergo extensive first pass metabolism: a- by digestive enzymes: as insulin. b- by hepatic microsomal enzymes as Nitroglycerin. 1- Mention this route of administration. Sublingual 2-Mention the advantages of this route Easy administration. Rapid onset of action (due to rapid absorption) Good bioavailability: bypassing the gut and hepatic first pass effect. Proper control of dose: if adverse effects developed by either spitting or swallowing the rest of the drug What is the route of administration of these dosage forms? inhalation route 1- Mention the advantages of this route of administration: Excellent & Rapid absorptions due to: Large surface area Thin porous membrane Rich blood supply of the alveoli. 2- Mention the disadvantages of this route of administration. : Inaccurate dosing. Drug may irritate pulmonary epithelium -Mention the name of these dosage forms A B A) Ampoule B) Vial The route of administration of the 2 previous dosage forms are: Parenteral (I.V , I.M or SC) Oily preparations is injected by……… Intra-muscular The onset of action in this injection is within 5-10 minutes The fluid amount of this injection Less than 5 ml Mention 2 common sites for this type of injection.  Dorsogluteal  Ventrogluteal  Deltoid.  Vastus lateralis.  Rectus femoris. The possible Vehicle of this type of injection are Aqueous,suspension or oily Needle angle is: 90˚  The type of injection is Intradermal  The volume of the fluid injected should be Less than 0.5 ml  The site of choice of this injection is Ventral forearm  Mention 2 uses for this type of injection: Sensitivity test Immunization eg. BCG vaccine  Needle angle: 15˚ (almost flat)  Why Massage Not needed causes irritation 1-The type of this injection is INTRA-VENOUS 2-Mention 2 specific types of this route of administration BOLUS INFUSION 3-Common sites of injection: a- Peripheral veins: dorsum of the hand, cephalic vein, basilic vein, antecubital. b- Central veins: internal jugular vein, subclavian, femoral. c- In infants: scalp veins, umbilical vein (first 2 weeks of life). 4- Needle angle: 30˚ 6-Mention 4 Advantages of this route:  Immediate onset (useful in emergencies).  100% bioavailability ( useful in emergencies).  High plasma concentration.  Useful for irritant drugs.  Useful for large volume drugs. Mention 4 disadvantages of this route: Local:  Phlebitis, thrombophlebitis, thromboembolism.  If extravasation of an irritant drug: severe pain and inflammation.  If oily: occludes the vein and causes embolism. Systemic:  Anaphylaxis: if the patient is allergic to the drug.  Velocity reaction: arrhythmias, hypotension or cardiac arrest might occur when rapidly injecting some drugs as aminophylline.  Transmission of diseases: as viral hepatitis, AIDS.  Pyrogenic reaction: if sterility is not achieved during injection. Is this route useful in emergency? If yes: Mention 3 possible reasons. YES,DUE TO: 100%bioavailability Immediate onset. High plasma concentration 1-The type of injection is  SUBCUTANEOUS 2-Common sites of injection:  - Outer arm. - Abdomen - Thigh.  - Buttocks. 3-Fluid amount:  Less than 1 ml 4-Onset of action:  10-30 minutes Delayed by: Vasoconstrictors.  Shock  Cold application. 5-Vehicle:  Aqueous solution or Suspension. 6-mention 3 drugs can be given by this type of injection: HEPARIN------> THROMBOEMBOLICDISORDERS. INSULIN--------->DIABETESMELLITUS. -ADRENALINE--------->ANAPHYLACTICSHOCK. For the illustrative diagram 1-Mention route of Administration? A) I.M B) S.C C) I.D D) I.V 2-Mention one important character for each route ? IM injection:  oily drugs, depot preparation could be administered SC: DO NOT USE irritant drugs ID: used for sensitivity test or Vaccine IV:  used for administration of large volume of fluids, blood transfusion, drugs either bolus injection or I.V infusions  irritant drugs could be administered intravenously while oily preparations are contraindicated