Rout of drugs administration.pptx34567890poiuytresdfg

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1. Rout of drugs administration Definition: Route of administration is defined as the ways by which drugs can be given into the body

2. Factors to be considered when choosing certain route: Site of drug action : e.g., treatment of certain GIT diseases necessitates giving the drug orally. Onset of action : treatment of emergency conditions necessitates the use of intravenous route. Duration of action : drugs intended for longer duration of action are given by a route when absorption is slow.

3. Factors to be considered when choosing certain route: 4) Patient status: oral route cannot be used when the patient is unconscious, or has difficulty in swallowing, or has repeated vomiting 5) Desire of the patient.

4. A- Enteral - Drug Placed Directly In The GI Tract: Absorption from GIT affected by : 1-Surface area 2-Blood flow to site of absorption 3-Physical state: solid, solution, suspension 4-Water solubility 5-Concentration at the site of absorption 6-Particle size

5. 1- ORAL ROUTE :- two methods of administration: A -applying topically to the mouth B -swallowing for absorption along the gastrointestinal (GI) tract into systemic circulation. ex aspirin, paracetamol * is the abbreviation used po (from the Latin per os)

6. ADVANTAGE OF ORAL ROUTE : 1- Simple, convenient, and acceptable. 2- Oral drugs can be given in different dosage forms. 3- Safe route: since in overdose, it can be managed easily. 4- The drug can be placed at the site of action (e.g., antihelminthic )

7. Disadvantages : 1- Some drugs are destroyed in the gut (e.g., some penicillin's, insulin, oxytocin). 2- Tablets taken with too small a quantity of liquid and in supine position can lodge in the esophagus with delayed absorption and may even cause ulceration (e.g., doxycycline). 3- Some drugs may cause gastric irritation 4- Absorption may be affected by food ( tetracyclines ) or by other drugs which inhibit gut motility e.g., antimuscarinic

8. 5-First pass metabolism (by intestinal wall and by the liver ) limits the efficacy of some drugs when taken orally. 6- Sometimes may have adverse reactions – e.g. Antibiotics may kill normal gut flora. 7- Not suitable for unconscious patient

9. First pass metabolism : 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

10. 2- Buccal/Sublingual route:

11. Sub lingual route :ex (Nitroglycerin ,)

12. ADVANTAGE: 1-Avoid hepatic first pass(high bioavailability |). 2-Rapid absorption. 3-Drug stability.

13. DISADVANTAGE : 1-irritent to oral mucosa 2- only few drugs are absorbed by this route 3- inconvenient 4- cannot give large doses

14. 3-RECTAL ROUTE: *Most commonly by suppository or enema * In this form, a drug is mixed with a waxy substance that dissolves or liquefies after it is inserted into the rectum. ex- Diazepam

15. ADVANTAGES 1-By-pass liver - Some of the veins draining the rectum lead directly to the general circulation, thus by-passing the liver. Reduced first-pass effect 2- use in children. 3- use in vomiting and unconscious patient . 4-high concentration is achieved rapidly .

16. Disadvantage : 1-incovenient 2-slow absorption 3- irritant and inflammation to rectal mucosa may be occur

17. Q/answer by (T) or (F) for the following statement : Route of administration is defined as the ways by which drugs can be given into the body Oral route consider as systemic and local route . Onset of drugs action not consider as importance factor in choosing the suitable route. Oral route suitable for unconscious patient. Absorption from GIT not affected by surface area and water solubility. Oral route consider safe route. Absorption of all drugs will be affected by food. The best way to give nitroglycerin is Buccal route. Drugs that give by Buccal or sublingual route are destroyed by acidity of mouth. Rectal route commonly use in adult.

18. Answers: 1- T 2- T 3- F 4- F 5- F 6- T 7- F 8- F 9- F 10- F