Date post: | 07-May-2015 |
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Health & Medicine |
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Dr.U.P.RathnakarDr.U.P.RathnakarMD.DIH.PGDHMMD.DIH.PGDHM
Pharmaceutical processDrug reaches the patientPharmacokinetic processWhat body does to the drugPharmacodynamic processWhat drug does to the bodyPharmacotherapeutic process
Therapeutic effect on the patient
Enteric-coated Tablet
Tablet
Extended-release tablets
Capsules
Mixtures
Injections
Vials
Ampoules
Inhalers Ointments/Creams; Powders
Routes of Drug Administration
Routes of Drug Administration
Route of administration
is the path by which a drug, is brought into contact with the body
Routes of Drug Administration- Classification
A. Local : Topical, Deep tissues, Intra-arterialB. Systemic1. Oral2. Rectal3. S.L.4. Trans Cutaneous5. Injections – s.c, i.m, i.v., intradermal6. Inhalation7. Nasal
Enteral
Parenteral
Local RouteTopical: Local action Ointments, powders, eye drops, paints,
lozenges, unabsorbable drugs, Inhalers for Asthma
Deeper tissues: Intra articular, alveolar block, intrathecal
Intrarterial- Contrast media, cancer therapy
Local Route - EnemaEvacuant enema:- Eg: Soap & water enema , AIM:-to remove faecal matter & flatus
Retention Enema: [Suppositories] Local action:- Eg: Prednisolone enema in
ulcerative colitis.Systemic action[Transrectal]:-MgSO4 to ICT.
Diazepam in epilepsyAdvantages & Disadvantages of
rectal route Vs oral 50% of the drug escapes liver. Embarrassing, Irritation
SublingualDrug placed under the tongue or crushedAdvantages of S/L route- 1.Rapid onset2.Quick termination of the drug effect3.No effect of gastric juice
Disadvantages:- 1.Irritants and non-lipid soluble canot be given
Eg. Nitroglycerine , Buprenorphine, Desaminooxytocin
Oral or Enteral route Advantages :1. Safer2. More convenient3. Economical4. Painless5. Self administration possible6. Complications of parenteral therapy avoided Disadvantages.1. Slow onset2. Irritant & unpalatable drugs can not be given.3. Vomiting, unconscious pts.- not useful4. Drugs which are destroyed by digestive juices -- not
useful.
Tab, Cap, Syp, Enteric coated pills / tablets, Controlled release
PARENTERAL ROUTE s.c, i.m, i.v., intradermal ADVANTAGES1.Unconscious & un-cooperative pt.2.Vomiting & diarrhoea3.Emergencies.4.Irritant drugs (I.V.route)5.Drugs which are destroyed by G.I.
enzymes - given safely.
PARENTERAL ROUTE….DISADVANTAGESLess safeMore expensiveInconvenientSelf medication is difficultPainful.Chances of local tissue injury,& injury to nervesRequires sterilization of instrumentsSkilled
Pressured metered dose aerosols/inhaler- eg.Salbutamol, Beclomethsone.
Oxygen or compressed air driven nebulised solutions- eg. Salbutamol.
Dry powders from inhalers activated by patients inhalation –eg. Salbutamol
Gases eg. General anaesthetics, Oxygen
Inhalation:
LocalAction
SystemicAction
•To prevent dry mouth and hoarseness, rinse mouth after each use. •It is important to practice good oral hygiene to prevent mouth infections•Tooth decay ?
NebulizerMetered dose inhaler
InjectionsIntradermal :
B.C.G Vaccination; Drug sensitivity tests.
Subcutaneous (S.C):Only non-irritant drugs.Insulin; Adrenaline
INTRAMUSCULAR ROUTE : (i.m)Deltoid, Gluteus, Rectus femoris,Mild irritants, suspensionsshould not exceed 10 ml
Intradermal
i.v.injection
IntravenousIntravenous (I.V) route. : Advantages1.100% bioavailability2.Emergencies.3.Large volumes4.Irritant drugs. Eg.- I.V. Nitrogen mustard
Intravenous…DisadvantagesIts action cannot be haltedLocal irritation can lead to phlebitisSelf medication is difficult.Requires sterilization of instruments.Precautions: Should be given slowly. Ensure that the needle is in the vein.
Alveolar Blocks
TranscutaneousIontophoresis: Galvanic current eg:salicylates.
Jet injections:- High velocity jetNo needle –painlessSuitable for mass inoculation. Jet injections for insulin also available.
TRANSDERMAL DRUG DELIVERY SYSTEMTransdermal therapeutic system[TTS]
Eg.Scopolamine, Nitroglyserine, Nicotine.
Trans-nasal route
Postpituitary extract in Diabetes insipidus.
GnRH, & Calcitonin [Nasal decongestant-Topical]
Factors deciding the choice of routePhysical & chemical properties-
Solid/Liquid/Gas, Irritancy, pHSite of desired action- Local or
systemicRate of absorption from a routeEffect digestive juice and First pass
metabolismRoutine or emergencyAccuracy of dosageCondition of Pt.-Unconcious, vomiting