routes of drug adminstration

Pharmacokinetic 1Route of administration By Dr . Safia A. Al-rezami .

Dr .safia A alrezami

What mean Routes of Drug Administration?-The path by which a Drug, fluid, poison, or other substance is come into contact with the body . - May be systemic \ topical .The possible routes of drug entry into the body may be divided into classes :*Enteral.*Parenteral.*Inhalation (Pulmonary absorption).*Topical Application.

1- INTRODUCTION


1- Routes


1-Enteral Routes

Drug placed directly in the GI tract, desired effect is systemic (non-local), substance is given via the digestive tract-oral -sublingual

-buccal-rectum Absorption through the rectum

NUMBER ONE


route 1-Oral

Dosage from :1-tablets

2-capsules3-powder

4-syrup5-mixture suspension

6-emulsion

1- Enteral Routes



Advantages

1-Convenientcan be self administered, pain free, easy to take, more safe and acceptable to patient.

2-Cheap compared to most other parenteral routes.

3-Systemic distribution

Disadvantages

1-Absorption variable absorption slow or irregular

2-First-pass effect drugs absorbed orally are initially transported to the

liver via the زportal vein3-Esophageal ulceration

-irritation to gastric mucosa nausea and vomiting.4-Destruction of drugs by gastric acid and digestive juices . insulin, oxytocin destroyed in gut

route 1-Oral

1- Enteral Routes


2-Sublingual route

Dis advantage : unpleasant taste and Only for lipid soluble drug. Dr .safia A alrezami

1- Enteral Routes

3 -Buccal route

the area inside the mouth between the lining of cheek (the buccal mucosa ) and the teeth / gums . Certain medications are designed to be given bucally .Buccal (as opposed to oral) administration usually results in a more rapid onset of action, since the medication need not pass through the digestive system and can be absorbed directly through the skin. There is current research on developing buccal morphine, as well as insluine . Some sedatives can be given buccally, e.g. midazolam .


Absorption through rectum various drugs

in suppository or enema form Like sublingual not effect by first pass

metabolism or enzyme

4 -Rectum route

1- Enteral Routes


Advantages

1-Unconscious patients and children, if patient is nauseous or vomiting .

2. The metabolism of drugs by liver is minimized.

3.Good for drugs affecting the bowel such as laxative.

Disadvantages

1-Absorption incomplete irregular in lower rectum.

2. Irritation.

3- Un–accept route by patient .

route 4-rectal

1- Enteral Routes


Need in 1-poorly absorbed drug from GIT e.g insulin2-Unconscious patients3-Rapid onset of action4-Control over the actual dose of drug Dosage from :( ampule ,vials).Three major parenteral :Intravascular (IV)placing a drug directly into the blood stream.Intramuscular(IM)drug injected into skeletal muscle. Subcutaneous(SC)Absorption of drugs from the subcutaneous tissues.

11- Parenteral Routes

2-Parenteral route


Advantages

1- Direct to the blood.

2-If drug un stable in GIT.

3- NO first pass metabolism.

4-For un conscious patient .

Disadvantages

1- Need sterility .

2- Need experience.

3-Painful.

4- Can not adverse the effect


Parenteral route


Use

•Suitable for large volume, irritating drugs.• Must inject slowly as a rule.• Complete bioavailability.• E.g Thiopentol, diazepam IV for quick effect

Advantages• Direct. • No first pass effect .• IV inj. Immediate effects.• Valuable for emergency.

Disadvantages• Requires IV access.• Hard to remove.• Vascular injury.• Lack of sterility may cause viral hepatitis or AIDS.


Intravenous (IV)


Use

•Suitable for small volume of oil drugs.• Must inject slowly.

Advantages

• Good for depot storage (if oil based) Rapid onset of Action. e.g vaccines, antibiotics.

Disadvantages• Pain at site of injection


Intramuscular (IM)


Use

•Suitable for large volume, irritating drugs.• Must inject slowly as a rule.• Complete bioavailability.• E.g Thiopentol, diazepam IV for quick effect

Advantages

• Non irritating small volumes Even slow absorption e,.g Adrenaline in local anesthetics.

Disadvantages• Pain, necrosis, • Absorption of solid pallets implanted under the skin occurs slowly over weeks or months, e.g Testosterone Insulin, adrenaline, heparin, vaccines inj. SC.


Subcutaneous (SC)


Immediate action in lungs Rapid delivery to blood Local or systemic action.*gaseous and volatile agents and aerosols rapid onset of action due to rapid access to circulation :a. large surface area .b. thin membranes separates alveoli from circulation . c. high blood flow.

111- Inhalation Routes

3-Inhalation route


Advantages Instantaneous

absorptionUser can titrate (regulate the amount of drug they are receiving). Avoids hepatic first-

pass loss. Local application at

the desired site of action in pulmonary disease.

Treatment of bronchial asthma.

Disadvantage

Must be in gas, vapor or aerosol form.

In exactly dose .

111- Inhalation Routes

3-Inhalation route



• Topical medication is a medication that is applied to body surface such as the skin or Mucosal membranes to treat ailments via a large range of classes including but not limited to creams, foams, gels, lotions, and ointments.•Mucosal membranes• (eye drops, antiseptic, sunscreen, callous removal, nasal) •Skin a. Dermal - rubbing in of oil or ointment (local action) 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 .

1v- Topical Routes 4 -Topical route

http://en.wikipedia.org/wiki/Creams

http://en.wikipedia.org/wiki/Foams

http://en.wikipedia.org/wiki/Gels

http://en.wikipedia.org/wiki/Lotions

http://en.wikipedia.org/wiki/Ointments

Advantage

Convenient Effects are limited to area of application Localized.

Limited systemic absorption.

Disadvantage

Effects are limited to area of application.

Irritation .No exactly dose .

1v- Topical Routes

4-Topical route


Other

Mucosal membranes

Dr .safia A. alrezami

Eye drops Ear drops Nasal drops

Dr .safia A. alrezami

The end

Health & Medicine

routes of drug adminstration