Medication/ Medication Administration Part 2

Routes of drug administration

Lecture Objective Describe the various techniques of drug administration.

Routes of drug administration Definition: A route of administration is the path by which a drug, fluid, poison or other substance is brought into contact with the body.

ROUTES OF DRUG ADMINISTRATION ENTERAL PARENTERAL TOPICAL INHALATION ROUTE

ENTERAL ORAL RECTAL BUCCAL SUBLINGUAL

Administration of oral medication Definition: Drugs given by the oral or gastric route are absorbed into the bloodstream through the gastric or intestinal mucosa. Usually the patient swallows the drug. Forms of oral medications: Tablets. Capsules. Liquid drugs like syrup Also available as powder, granules or oil.

ORAL Advantages Convenient - can be self- administered, pain free, easy to take Absorption - takes place along the whole length of the GI tract Cheap - compared to most other parenteral routes

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 cont. 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

SUBLINGUAL ROUTE rapidly absorbed by sublingual mucosa Sublingual administration is where the dosage form is placed under the tongue rapidly absorbed by sublingual mucosa

SUBLINGUAL ROUTE ADVANTAGES DISADVANTAGES Economical Quick termination First-Pass avoided Drug absorption is quick DISADVANTAGES Unpalatable & bitter drugs Irritation of oral mucosa Large quantities not given Few drugs are absorbed

BUCCAL ROUTE Buccal administration is where the dosage form is placed between gums and inner lining of the cheek (buccal pouch) absorbed by buccal mucosa

BUCCAL ROUTE - unpleasant taste of some drugs ADVANTAGES – Avoid first pass effect – Rapid absorption – Drug stability DISADVANTAGES – Inconvenience – advantages lost if swallowed – Small dose limit - unpleasant taste of some drugs

RECTAL ROUTE ADVANTAGES USED IN CHILDREN LITTLE OR NO FIRST PASS EFFECT USED IN VOMITING/UNCONSCIOUS HIGHER CONCENTRATIONS RAPIDLY ACHIEVED DISADVANTAGES INCONVENIENT IRRITATION OR INFLAMMATION OF RECTAL MUCOSA CAN OCCUR Erratic absorption

Con… RECTAL DRUGS: Most commonly by suppository or enema.

Giving Medication Through an NG Tube Holding the nasogastric (NG) tube at a level some what above the patient's nose, pour the diluted medication into the syringe barrel. Hold the at a slight angle and add more medication before the syringe empties. rise the tube slightly higher to increase the flow rate.

Continue Giving Medication Through an NG Tube Give medications separately and flush with water between each drug. After you've delivered the whole dose, position the patient on her/ his side, head slightly elevated.

SYSTEMIC-PARENTERAL Parenteral administration is injection or infusion by means of a needle or catheter inserted into the body The term parenteral comes from Greek words para, meaning outside enteron, meaning the intestine This route of administration bypasses the alimentary canal

Parenteral Route (cont…) ADVANTAGES Action is rapid Administered even in unconscious patients Gastric irritant can be avoided parenterally Used in patients who are unable to swallow

Parenteral Route (cont…) DISADVANTAGES Asepsis must be maintained Injection may be painful more expensive, less safe and inconvenient Injury to nerve may occur

Injections Intradermal Subcutaneous Intramuscular Intravenous Intraperitoneal Intrathecal Intraarticular Intra arterial Intra medullary Parenteral (or injectable) routes include: Intravenous – into the vein Intramuscular – into the muscle Subcutaneous – into the subcutaneous layer of the skin Intradermal – into the dermal layer of the skin Intrathecal – into the subarachnoid space (used for anesthesia) Intraarticular – into a joint

Injections Intradermal into the dermal layer of the skin Subcutaneous into the subcutaneous layer of the skin Intramuscular into the muscle Intravenous (fastest delivery into the blood circulation) into the vein Intraperitoneal into the peritoneum Parenteral (or injectable) routes include: Intravenous – into the vein Intramuscular – into the muscle Subcutaneous – into the subcutaneous layer of the skin Intradermal – into the dermal layer of the skin Intrathecal – into the subarachnoid space (used for anesthesia) Intraarticular – into a joint

Injections Intrathecal into the subarachnoid space (used for anesthesia) Intraarticular into a joint Intra arterial into arteries Intra medullary into bone marrow Parenteral (or injectable) routes include: Intravenous – into the vein Intramuscular – into the muscle Subcutaneous – into the subcutaneous layer of the skin Intradermal – into the dermal layer of the skin Intrathecal – into the subarachnoid space (used for anesthesia) Intraarticular – into a joint

Kinds of Parenteral Drug Containers Glass ampules Single and multidose vials syringes Intravenous medication fluids

Ampules and Vials Vials Ampules

Syringes and Needles Syringe Hypodermic needle

Intradermal Injection

Intradermal Administration Used for diagnostic purposes such as (tuberculin test, to determine sensitivity to various substances) Site: inner forearm (may use back and upper chest) drug is given within skin layers (dermis) Painful Volume: 0. 1-0.5 ml Equipment: (1ml, 25-27g, ⅝ or ½ inch needle). Administration angle: 10-15° Forearm: one hand’s breath above wrist

Subcutaneous Injection

Subcutaneous Administration Administered into subcutaneous tissue that lies between the skin and the muscle. Common subcutaneous injections are heparin, insulin and certain immunization. Volume: no more than 1ml Equipment: Insulin syringe (25-30g, ½ to⅝ inch needle). Administration Angle: 45° or 90 ° 45---pinch an inch 90-----pinch two inches

Subcutaneous injections SITES OF SUBCUTANEOUS INJECTION Upper ventral or dorsogluteal Anterior aspect of thigh Abdomen and upper back Outer aspect of the upper arm

Intramuscular Injection

Intramuscular Administration Administered into a muscle or muscle group Volume: no more than 5ml into single site for an adult with will developed muscles. Equipment: 1-5 ml syringe, needle (18-23 g, ⅝ to 3 inch needle). Administration angle: 90°

Intramuscular Ventrogluteal site Vastus lateralis site SITES OF INTRAMUSCULAR INJECTIONS Ventrogluteal site Vastus lateralis site Dorsogluteal site(should not to be used for children younger than 3 years) Deltoid site

Intramuscular Injection Sites Photo Source: Lippincott, Williams & Wilkins, Connection, Image Bank, http://connection.lww.com/products/smeltzer9e/imagebank.asp

Intramuscular Advantages suitable for injection of drug in aqueous solution (rapid action) and drug in suspension or emulsion (sustained release). Disadvantages Pain at injection sites for certain drugs.

Deltoid Injection Site

Intramuscular Administration Vastus Lateralis

Intramuscular Administration VentroGluteal

Intramuscular Administration DorsoGluteal Most dangerous site because of sciatic nerve location

Z-track IM Administration Method used to prevent seepage of medication into the needle track and to reduce pain and discomfort . e.g; Iron Used to “trap” medication in muscle and prevent “tracking” of solution through tissues. Equipment: needle at least 1.5 in

Intramuscular Administration Z-Track For solutions irritating to the tissues. Pull skin away from site to displace tissue Inject medication Don’t massage after injection Photo Source: Lippincott, Williams & Wilkins, Connection, Image Bank, http://connection.lww.com/products/smeltzer9e/imagebank.asp

Z-Track

Pediatric IM Injection Thigh is preferred site in pediatric Especially used in infants and young toddlers Large muscle mass No proximal nerves or blood vessels Limited subcutaneous fat layer More developed muscle than other sites Can accommodate larger volumes than other pediatric injection sites

When to Aspirate (IM & SC injection) The reason for aspiration before injection a medication is to ensure that the needle is not in a blood vessel. If blood appears in the syringe, withdraw the needle, discard the syringe, and prepare a new injection.

When Not To Aspirate When administering SC heparin/ insulin, it is recommended that you do NOT aspirate. Because of the anticoagulant properties of heparin, aspiration could damage surrounding tissue and cause bleeding and bursting. Insulin needle is so small.

Intravenous Administration (IV) Involves injection of drugs directly into bloodstream Drugs act rapidly DRUGS CAN BE GIVEN IV AS; 1, bolus 2 , infusion (intermittent or continuous infusions)

Intravenous Administration (continued) Disadvantages: Time and skill required for venapuncture Difficulty in maintaining an IV line Greater potential for adverse reactions Possible complications of IV therapy,e.g.Infiltration, Phlebitis, Cellulitis, Septicemia , Pulmonary edema and air embolism-

Con…

Intravenous devices e.g. - Piggyback (IVPB). Volume control administration set. Mini- infusion pump.

Intravenous Mini- infusion pump

Main Veins of the Arm

Topical Routes of Administration Topical administration is the application of a drug directly to the body site. Action: local or systemic. Includes administration of drugs to any mucous membrane eye – vagina nose – urethra ears – colon lungs

Topical Dosage Forms Eye or ear: solutions suspensions ointments Dose forms for topical administration include: Skin: creams ointments lotions gels transdermal patches disks Eye or ear: solutions suspensions ointments Nose and lungs: sprays and powders

Transdermal Route This involves applying to the skin disk or patch that contains medication intended for daily use or for longer intervals. Transdermal patches are commonly used to deliver hormones and narcotic analgesics.

Transdermal Route absorption of drug through skin (systemic action) i. stable blood levels ii. no first pass metabolism

EAR (OTIC) INSTILLATION Definition: Instill liquid medication into external auditory canal for such therapeutic effects. Purpose: To treat infection and inflammation. To soften cerumen for removal. To produce local anesthesia. To aid in removal of foreign body trapped in the ear.

Positioning The Client For Eardrop Instillation Before instilling eardrops, have the client lie on his or her side. Then straighten the ear canal to help the medication reach the eardrum. For adult, gently pull the auricle up and back. For young child and infant, gently pull down and back

ADMINISTERING OPHTHALMIC MEDICATIONS Definition: Medications are instilled in mucous membranes of eye for various therapeutic effects. Purpose: To treat infection. To relieve inflammation. To treat eye disorders such as glaucoma. To diagnose such as foreign bodies and corneal abrasions.

Instill eye drops Rt. = O.D. ,Lt. = O.S. and both = O.U.

Administering Medications by Inhalation Advantages A- Large surface area B- thin membranes separate alveoli from circulation C- high blood flow As result of that a rapid onset of action due to rapid access to circulation

Inhalation route Disadvantages 1- Most addictive route of administration because it hits the brain so quickly. 2- Difficulties in regulating the exact amount of dosage. 3- Sometimes patients having difficulties in giving themselves a drug by inhaler. .

Con… Drugs for inhalation may be administered by: a nebulizer. Metered-dose inhaler.

Small volume nebulizer

Nebulizer with attached face mask, bag-valve mask, and endotracheal tube

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