Routes of Drug Administration PDF

Routes of drug Administration PHARMACOLOGY LAB Routes of Administration ฀ Various dosage forms of drugs are used in therapy ฀ Drugs need to be presented in a form that can be administered to an organism ฀ Drug formulation can allow: specific tissue sites to be - sel...

Routes of drug Administration PHARMACOLOGY LAB Routes of Administration ฀ Various dosage forms of drugs are used in therapy ฀ Drugs need to be presented in a form that can be administered to an organism ฀ Drug formulation can allow: specific tissue sites to be - selectively targeted or - systemic absorption of the drug to be avoided  Classification Route of Administration Systemic Local ฀ Skin Topical Enteral Parenteral ฀ Ocular drops ฀ ฀ Oral Intranasal ฀ Inhalation ฀ ฀ Sublingual/buccal ฀ Transdermal Mucosal-throat, ฀ Rectal vaginal & ear ฀ Injection  Routes of Administration ฀ The appropriate drug given in the correct dosage will often hasten a patient's recovery ฀ On the other hand, an inappropriate drug or dosage may worsen a patient's condition or even result in his death ฀ Remember that there are six "rights" in the administration of drugs: 1. Right patient 2. Right drug 3. Right dose 4. Right route 5. Right time 6. Right documentation Routes of Administration  Routes of Administration A- Systemic 1- Enteral a. Oral b. Sublingual /buccal c. Rectal Routes of Administration a. Oral ฀ Dosage forms: Oral Tablets: ✔ Enteric-coated preparations ✔ Extended-release preparations Oral Capsules Oral Liquids  Routes of Administration a. Oral ฀ Advantages and Disadvantages Advantages 1. Most convenient and cheapest 2. Non-invasive, painless and no assistance is required (self administer) 3. Aseptic precautions are not required. 4. Both, solid and liquid dosage forms can be given Routes of Administration a. Oral Disadvantages 1. Action is slow (slow onset of action) so it is not suitable for emergency 2. Unpalatable or irritant drugs (e.g. paraldehyde and chloramphenicol) are difficult to administer 3. It can not be used for: un cooperative/ unconscious/ vomiting patients  Routes of Administration 4. It may cause gastrointestinal adverse effects e.g. aspirin (can cause peptic and duodenal ulcers) 5. Certain drugs are not absorbed (unabsorbable drugs) if given by this route e.g., amikacin 6. Certain drugs are: - destroyed by gastric juices (penicillin G, insulin) or - extensively metabolized during first pass in the liver or GIT (e.g. - nitroglycerine, testosterone, lidocaine) Routes of Administration 2. Parenteral (Par = beyond, Enteral = intestinal) ฀ Any method of drug administration that avoids the gastrointestinal tract is termed parenteral administration as the drugs bypass the GIT ฀ Dosage forms: ฀ Inhalation ฀ Transdermal ฀ Injection Intravenous, Intramuscular, Intraarterial Intradermal, Subcutaneous Intra-articular, Intrathecal  Routes of Administration Routes of Administration ฀ Advantages and Disadvantages Advantages 1. Rapid onset of action and high accuracy of dose are ensured 2. They can be employed in an unconscious or an uncooperative patient 3. They can be employed in cases of vomiting and diarrhea 4. In the patients unable to swallow  Routes of Administration 5. Drugs which might irritate the stomach or which are not absorbed orally can be administered, e.g. aminoglycosides. 6. They avoid drug modification by the alimentary juices and liver enzymes (avoidance of first pass metabolism by the liver) e.g. – Insulin - nitroglycerine Routes of Administration Disadvantages 1. Less safe, once given the action of given drug will become irreversible 2. More expensive 3. Invasive method and Inconvenient for use, self-medication being difficult and basic equipment needed for parenteral administration includes: needles, syringes, ampules or vials, solutions, powders and others  Routes of Administration 4. Liable to cause infection if proper care is not exercised 5. Painful and likely to injure important structures such as nerves and arteries if not given properly Routes of Administration B. Local ฀ This refers to the application of a drug to an area of the body for direct treatment ฀ Usually there is inefficient systemic absorption (1-15%), but high local tissue levels is achievable, often higher than by systemic route ฀ Toxicity usually not a problem  B. Local ฀ Dosage forms Eye ฀ Eye Drops and Eye Ointment Nose฀ Nasal Drops and Nasal spray Vaginal pessaries ฀ Vaginal tablet, ointment, gel, powder, lotion, etc. Topical ฀ Cream, Ointment, lotion and Gel Local inhaler Routes of Administration ฀ Important procedures to be followed: 1 ฀ When applying eye drops: 1. Wash your hands 2. Do not touch the dropper opening 3. Look upward 4. Pull the lower eyelid down to make a 'gutter' or pouch 5. Bring the dropper as close to the 'gutter' as possible without touching it or the eye 6. Instill the prescribed number of drops (1 drop/application) in the 'gutter' 7. Close the eye for about two minutes (Do not shut the eye too tight) 8. Excess fluid can be removed with a tissue (Do not rub)  Routes of Administration Notes: ฀ If more than one kind of eye drop is used wait at least five minutes before instilling the next drops ฀ Eye-drops may cause a burning feeling but this should not last for more than a few minutes. If it does last longer, consult a doctor or pharmacist Routes of Administration 2 ฀ When applying eye ointment: 1. Wash your hands 2. Do not touch anything with the tip of the tube 3. Tilt the head backwards a little 4. Take the tube in one hand and pull down the lower eyelid with the other hand, to make a 'gutter' 5. Bring the tip of the tube as close to the "gutter" as possible 6. Apply the amount (usually 1 cm length) of ointment 7. Close the eye for two minutes 8. Remove excess ointment with a tissue 9. Clean the tip of the tube with other tissue 3 Routes of Administration ฀ When applying ear drops: 1. Lie on one side with the ear upward 2. Gently pull the lobe to expose the ear canal 3. Instill the amount (usually 4-5) of drops 4. Wait for five minutes before turning to the other ear 5. Use cotton wool to close the ear canal after applying the drops (only if the manufacturer explicitly recommends this) 6. Ear drops should not burn or sting longer than a few minutes 4 Routes of Administration ฀ When using inhaler: 1. Cough up as much sputum as possible. 2. Shake the inhaler before use. 3. Hold the inhaler as indicated in the manufacturer's instructions (this is held usually upside down). 4. Fully exhale. 5. Place the lips tightly around the mouthpiece. 6. Tilt the head backward slightly. 7. Breathe in deeply and activate the inhaler (press the metallic bottle), keeping the tongue down. 8. The aerosolized medicine is drawn into the lungs by continuing to inhale deeply before holding the breath for 10 seconds to allow absorption into the bronchial walls.  Routes of Administration Notes: - The co-ordination between activating the inhaler and breathing in is critical for effective delivery of the drug into the lungs. - You should leave at least 30 seconds before applying the next dose - Rinse the mouth after using corticosteroid-containing inhaler to avoid fungal infection.