Routes of administration (VK)
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Transcript of Routes of administration (VK)
Routes of Drug AdministrationRoutes of Drug Administration
ROUTES
MAIN TYPES
ENTERAL PARENTERAL TOPICAL/LOCAL
ENTERAL
ORALEX.-CAPSULE
SYRUP POWDER
SUSPENSION
SUBLINGUALEX.-NEFEDIPIN
ISOSORBITENITROGLYCERIN
ISOPRENALIN
RECTALDULCOLAX
GLYCERIN SUSP.OINTMENT
ENEMA,DIZEPAM
PARENTERAL ROUTE
INTRAVENOUS-Ex.-Glucose, N.S., Dextrose, Heparin.
INTRAMUSCULAR- Ex. –oily solution, antibiotics, vaccines, neuroleptics.
INTRAPERITONEAL- Ex- Antirabies, peritoneal dialysis.
INTRATHECALINTRATHECAL-Ex –Xylocaine inj.
INTRAMEDULLARY-Ex. Bone marrow transplantations, blood transfusion in child.
INTRAATERIAL –Ex. Anticancer drugs, for coronary angiography.
INTRA-ARTICULAR- Ex. Hydrocortisone, gold inj.
SUBCUTANEOUS- Ex. L.A., insulin,vaccine.
INHALATION- Ex.-Oxygen, salbutamol.
INTRADERMAL – Ex. Test sensitivity, BCG vaccine.
TOPICAL/LOCAL ROUTE
TRASDERMAL-Ex. Patch-nitroglycerin, scopalamine, clonidine.
CONJUNTIVAL – ex. Oint, drop, eg-gentamycin,ciprofloxacin.
VAGINA, URETHRA- Ex. Solu, oint, jelly, pessaries, suppository.
INNCTION(Rubbing)-Ex. Antifungal oint , powder, liniment.
MUCOUS MEMBRANE – Ex. Gargals, lozenges, mouth wash.
Routes of Drug Administration
The route of administration (ROA) that is chosen may have a profound effect upon the speed and efficiency with which the drug acts
ImportantImportantInfoInfo
Factors affecting choice of route
Physical and chemical properties of drugs. Site of desired action Rate and extent of absorption of drug
from different routes. Effect of digestive juices and first pass
metabolism. Rapidity with which response is desired. Condition of patient. Accuracy of dosage required.
Routes Of Administration
Local Systemic
Topical Enteralparenteral
Skinmucous membrane
Deeper tissues intraarticular, intrathecal, retrobulbar
Arterialanticancerous drugs, angiography
Routes Of Administration
Systemic routes Of Drug Administration
EnteralParenteral
OralInjection RectalRespiratoryCutaneous
The possible routes of drug entry into the body may be divided into two classes:
EnteralParenteral
Enteral Routes
Enteral - drug placed directly in the GI tract:sublingual - placed under the
tongueoral - swallowing (p.o., per os)rectum - Absorption through the
rectum
Sublingual/Buccal
Some drugs are taken as smaller tablets which are held in the mouth or under the tongue.
Advantages rapid absorption drug stability avoid first-pass effect
Sublingual/Buccal
Disadvantages inconvenient small doses unpleasant taste of some drug
Examples1. Nitroglycerine2. Isoprenaline3. clonidine
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
DisadvantagesSometimes inefficient - only part
of the drug may be absorbedFirst-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 juiceseffect too slow for emergenciesunpleasant taste of some drugsunable to use in unconscious
patient
First-pass Effect The first-pass effect is the term
used for the hepatic metabolism of a pharmacological agent when it is absorbed from the gut and delivered to the liver via the portal circulation. The greater the first-pass effect, the less the agent will reach the systemic circulation when the agent is administered orally
First-pass Effect
1. unconscious patients and children 2. if patient is nauseous or vomiting 3. easy to terminate exposure 4. absorption may be variable 5. good for drugs affecting the bowel such as laxatives6. irritating drugs contraindicated
Rectal
Parenteral Routes
Intravascular (IV, IA)- placing a drug directly into the blood stream
Intramuscular (IM) - drug injected into skeletal muscle
Subcutaneous - Absorption of drugs from the subcutaneous tissues
Inhalation - Absorption through the lungs
Routes of Drug Administrationcommon abbreviations…
PO = per os = oral
IV = intravenous = into the vein
IM = intramuscular = into the muscle
SC = subcutaneous = between the skin and muscle
IP = intraperitoneal = within the peritoneal cavity
icv = intracerebroventricular =directly into the ventricle of the brain
Oral Administration
Intestines
Liver
IntravenousAdministration
Metabolism
Intravascular
Absorption phase is bypassed (100% bioavailability)1.precise, accurate and almost immediate onset of
action, 2. large quantities can be given, fairly pain free
3. greater risk of adverse effects a. high concentration attained rapidly b. risk of embolism c. OOPS factor or !@#$%
Intramuscular
1. very rapid absorption of drugs in aqueous solution 2.repository and slow release preparations 3.pain at injection sites for certain drugs
Subcutaneous
1. slow and constant absorption 2. absorption is limited by blood flow, affected if circulatory problems exist 3. concurrent administration of
vasoconstrictor will slow absorption
Peridural Anesthesia
This is accomplished by injecting a local anesthetic into the peridural space, a covering of the spinal cord
Spinal anesthesia
Here, the local anesthetic is injected into the subarachnoid space of the spinal cord
1.gaseous and volatile agents and aerosols 2.rapid onset of action due to rapid access to circulation a.large surface area b.thin membranes separates alveoli from circulation c.high blood flowParticles larger than 20 micron and the particles impact in the mouth and throat. Smaller than 0.5 micron and they aren't retained.
Inhalation
Inhalation cont.
Respiratory system. Except for IN, risk hypoxia.
Intranasal (snorting) Snuff, cocaine may be partly oral via post-
nasal dripping.
Smoke (Solids in air suspension, vapors) absorbed across lung
alveoli: Nicotine, opium
Volatile gases: Some anaesthetics (nitrous oxide, ether)
petroleum distillates. Diffusion and exhalation (alcohol).
Lung-based transfer may get drug to brain in as little as five
seconds.
Topical
Skin a. Dermal-rubbing in of oil or ointment
(local action), paste, powder, cream, dressing, spray, etc
b. Transdermal - absorption of drug through skin (systemic action)
i. stable blood levels ii. no first pass metabolism iii. drug must be potent or patch
becomes to large
Mouth and pharynx- paints, lozynges, mouthwash, gargles.
Eyes, ear, nose- drops, ointments, irrigation, spray.
Git- nonabsorable drugs given orally.
Bronchi and lungs- inhalations,aerosols.
Urethra- ` jellys
vagina- Peseries, vaginal tablets,cream,powder.
Anal canal- ointments.
Mucosal membranes
intravenous 30-60 seconds intraosseous 30-60 seconds endotracheal 2-3 minutes inhalation 2-3 minutes sublingual 3-5 minutes intramuscular 10-20 minutes subcutaneous 15-30 minutes rectal 5-30 minutes ingestion 30-90 minutes transdermal (topical) variable (minutes to
hours)
Route for administration -Time until effect-
Time-release preparations
Oral - controlled-release, timed-release, sustained-release designed to produce slow,uniform
absorption for 8 hours or longerbetter compliance, maintain effect
over night, eliminate extreme peaks and troughs
Time-release preparations
Depot or reservoir preparations - parental administration (except IV), may be prolonged by using insoluble salts or suspensions in non-aqueous vehicles.
The ROA is determined by the The ROA is determined by the physical characteristics of the physical characteristics of the drug, the speed which the drug is drug, the speed which the drug is absorbed and/ or released, as well absorbed and/ or released, as well as the need to bypass hepatic as the need to bypass hepatic metabolism and achieve high metabolism and achieve high conc. at particular sitesconc. at particular sites
ImportantImportantInfoInfo
No No singlesingle method of drug method of drug administration is ideal for all administration is ideal for all drugs in all circumstancesdrugs in all circumstances
Very Important
Very Important
Info!Info!