Routes of administration...
5 likes2,208 views
The document outlines various routes of drug administration, categorizing them into enteral and parenteral routes, along with their advantages and disadvantages. Key enteral routes include oral, sublingual, and rectal, emphasizing factors like absorption rates and patient conditions. Parenteral methods, such as intravenous, intramuscular, and subcutaneous, are highlighted for their rapid onset and bioavailability but come with risks like infection and pain.
![ 1. ENTERAL
A. Oral
- Most common route of administration
- Most variable
- Most complicated pathway
- Cheapest
- Non - invasive
[NOTE: most drugs are absorbed in theGIT &
encounter the liver before they are distributed into
the general circulation]
po (from the Latin per os) oral route of medication administration
5](https://image.slidesharecdn.com/routesofadministration-210122091547/85/Routes-of-administration-5-320.jpg)
![1. ENTERAL
c. Rectal
- Useful if the drug induces vomiting if given orally or if
the patient is already vomiting
- Drainage of the rectal region bypasses the portal
circulation (No First Pass effect)
- Similar to the sublingual route, it prevents the
destruction of the drug by intestinal enzymes or by
the low pH in the stomach
- Unco-operative patient / in childrens
[commonly used to administer anti – emetic agents] 11](https://image.slidesharecdn.com/routesofadministration-210122091547/85/Routes-of-administration-11-320.jpg)
Routes of administration...
- 1. ROUTES OF DRUG ADMINISTRATION Dr. Rupali A. Patil Associate Professor & Head - Pharmacology GES’s Sir Dr. M. S. Gosavi College of Pharm. Edu. & Res., Nashik
- 2. 2
- 3. FACTORS GOVERNING CHOICE OF ROUTE • Physical & chemical properties of drug- solid/liquid/gas; solubility, stability, PH, irritancy • Site of desired action- localized and approachableor generalized and non approachable • Rate & extent of absorption from various routes • Effect of digestive juices & first pass effect • Rapidity of the desired response- emergency/routine • Accuracy of dosage • Condition of the patient- unconscious, vomiting 3
- 4. ENTERAL routes A. ORAL B. SUBLINGUAL C. RECTAL 4
- 5. 1. ENTERAL A. Oral - Most common route of administration - Most variable - Most complicated pathway - Cheapest - Non - invasive [NOTE: most drugs are absorbed in theGIT & encounter the liver before they are distributed into the general circulation] po (from the Latin per os) oral route of medication administration 5
- 6. Advantages 1. Safe 2. Convenient-self- administered 3. Pain free, non-invasive and easy to take 4. Economical- compared to other parenteral routes 5. Usually good absorption- takes place along the whole length of the GI tract 6. No need for sterilization 6
- 7. Disadvantages 1. Slow absorption: slow action - can not used in emergency 2. Irritable and unpalatable drugs- nausea and vomiting 3. Cannot be used Unco-operative, vomiting and unconscious patients 4. Some drugs destroyed 5. Sometimes inefficient drug absorbed,some drugs are not absorbed likestreptomycin 6. First-pass effect- Due to Biotransformation 7. Food–Drug interactions and Drug-Drug interactions 7
- 8. Dosage forms Capsules, powders Tablets, spansules Syrup, emulsion Suspension, elixirs Tablets Hard- gelatin capsule Spansule Soft- gelatin capsule Syrup 8
- 9. 1. ENTERAL B.Sublingual - Placement under the tongue - Allows the drug to diffuse into the capillaries & therefore to enter the systemiccirculation 9
- 10. Advantages: •Drug absorption is quick •Quick termination •Drug bypasses the intestine & liver : 1st -pass avoided •Can be self administered •Economical Disadvantages: •Unpalatable & bitter drugs •Irritation of oral mucosa •Large quantities not given •Few drugs are absorbed 10
- 11. 1. ENTERAL c. Rectal - Useful if the drug induces vomiting if given orally or if the patient is already vomiting - Drainage of the rectal region bypasses the portal circulation (No First Pass effect) - Similar to the sublingual route, it prevents the destruction of the drug by intestinal enzymes or by the low pH in the stomach - Unco-operative patient / in childrens [commonly used to administer anti – emetic agents] 11
- 12. Disadvantages: Inconvenient Absorption is slow and erratic Irritation or inflammation of rectal mucosa can occur By Suppository or enema: E.g. aspirin, theophylline, chlorpromazine 12
- 13. PARENTERAL routes SC / subcutaneous IM / intramuscular IV / intravascular 13
- 14. Parenteral Used for drugs which are Poorly absorbed in the GIT Unstable For unconscious patients Circumstances with rapid onset of action Provides the most control over the actual dose delivered to the body Greek words Para: outside Enteron: the intestine 14
- 15. parenteral Advantages Fast: 15–30 seconds forIV, 3–5 minutes for IM and subcutaneous(SC) 100% bioavailability suitable for drugs not absorbed by the gut or those that are too irritant (anti-cancer) IV can deliver continuous medication, e.g., morphine for patients in continuous pain, or saline drip for people needing fluids Disadvantages more risk of addiction when it comes toinjecting drugs of abuse Belonephobia, the fear of needles and injection. If needles are shared,there is risk of HIV and other infectious diseases It is the most dangerous route of administration If not done properly, potentially fatal air boluses (bubbles) can occur. Need for strict asepsis 15
- 16. 16
- 17. 2. PARENTERAL a. IV / intravascular - Most common parenteral route - For drugs which are not absorbed orally - Bypasses the liver - Permits a rapid effect & a maximal degree of control over the circulating levels of the drug - Can introduce bacterial contamination at the site - Can cause hemolysis 17
- 18. IV route… Advantages Bioavailability100% Desired blood concentrations achieved Large quantities Vomiting & diarrhea Emergencysituations First passavoided Gastric manupalation avoided Disadvantages Irritation& cellulitis Thrombophelebitis Repeated injections not Always feasible Less safe Technicalassistance required Danger of infection Expensive Less convenientand painful 18
- 19. 2. Parenteral b. IM / intramuscular Drugs administered aqueous sol’n specialized depot preparations 19
- 20. IM route… Advantages Absorption Reasonablyuniform Rapidonsetof action Mild irritantscan be given First passavoided Gastricfactorscan be avoided Disadvantages Only upto10ml drug given Local pain and abcess Expensive Infection Nerve damage 20
- 21. 2. Parenteral c. SC / subcutaneous - like IM requires absorption & somewhat slower than the IV route IMPLANT :a tablet or porous capsule is inserted into the loose tissues by incision of the skin, which is then stiched up. example : certain hormonal drugs 21
- 22. INTRA-ARTERIAL Rarely used Anticancer drugs are given for localized effects Drugs used for diagnosis of peripheral vascular diseases 22
- 23. INTRA-ARTICULAR injections of antibiotics and corticosteroids are administered in inflammed joined cavities by experts. example: hydrocortisone in rheumatoid arthritis 23
- 24. INTRADERMAL drug is given within skinlayers (dermis) Painful Mainly used for testing sensitivity to drugs. e.g. penicillin,ATS(antitetanus serum) INOCULATION:administration of vaccine (like small pox vaccine) 24
- 25. 3. Others a. Inhalation - Provides a rapid delivery of a drug across a large surface area of the mucus membranes of the respiratory and the pulmonary epithelium - Effect is as rapid as IV injection - For gaseous drugs 25
- 26. Advantages Fastest method, 7–10 seconds for the drugto reach the brain Disadvantages Typically a more addictive route of administration because it is the fastest, leading to instant gratification. Difficulties in regulating the exact amount of dosage Patient having difficulties administering a drug via inhaler 26
- 27. 3.Others b. Intranasal - Through the nose eg. : desmopressin, salmon calcitonin, cocaine 27
- 28. .Others c. Intrathecal, intraventricular - Introducing drugs directly into the cerebrospinalfluid /CSF Eg., amphotericin B 28
- 29. 3.Others d.Topical - Is used when a local effect of a drug is required - Eg. clotrimazole, atropine 29
- 30. Topical Routes of Administration Topical administration is the application of a drug directly to the surface of the skin Includes administration of drugs to any mucous membrane vagina urethra colon eye nose ears lungs 30
- 31. Topical Dosage Forms 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 31
- 32. Topical Route Advantages and Disadvantages Local therapeutic effects Not well absorbed into the deeper layers ofthe skin or mucous membrane lower risk of side effects Transdermal route offers steady level of drug in the system sprays for inhalation through the nose may be for local or systemic effects 32
- 33. Topical route Produce local effect to Skin (percutaneous) e.g. allergy testing, topical local anesthesia Mucous membrane of respiratory tract (Inhalation) e.g. asthma Eye drops e.g. conjunctivitis Ear drops e.g. otitis externa Intranasal, e.g. decongestant nasal spray 33
- 34. 3. Others e.Transdermal - achieves systemic effects by application of drugs to the skin, usually by using a transdermal patch. - Rate of absorption varies markedly - stable blood levels - no first pass metabolism - drug must be potent or patch becomes too large Eg. nitroglycerin 34
- 35. 35
- 36. Route for administration -Time until effect- intravenous intraosseous endotracheal inhalation sublingual intramuscular subcutaneous rectal ingestion transdermal (topical) 30-60 seconds 30-60 seconds 2-3 minutes 2-3 minutes 3-5 minutes 10-20 minutes 15-30 minutes 5-30 minutes 30-90 minutes variable (min to hrs) 36
- 37. Dosage forms available for different routes 37