Routes of Administration Flashcards
What is the therapeutic range?
-Range between the does causing minimum effective concentration and maximum safe concentration
What would happen to the plasma concentration-time curve is it was for an oral liquid or IV?
-Initial rate will be faster and will reach site of action faster
What does bioavailability depend on?
-Permeability of biological membrane, drug properties and other route -dependent factors eg stomach contents
What is first pass of presystematic metabolism?
-drugs adsorbed from the stomach, small intestine and upper colon pass into the hepatic portal system straight to the liver before it goes into ‘real’ circulation
What is phase I metabolism?
-Simple chemical changes eg oxidation. hydrolysis. Cytochrome P450 isoenzyme is important and products are likely to be inactive and more water soluble
What is phase II metabolism?
-Involves the conjugation of groups to the drug to increase its solubility. eg glucuronates and sulphates
What are the pharmacokinetic advantages of the inhalation route?
-Smaller doses can be used, reduces chance of side effects, fast onset as delivered to site of action, avoids first pass metabolism
What are the pharmacokinetic advantages of the transdermal route?
-Avoids first pass metabolism, controlled rate of drug delivery, reduces dosage frequency which increases compliance
How are drugs delivered rectally?
-Incorporated into a suppository which dissolves or melts within the rectum
What are the symptoms of sinusitis?
-Inflammation, obstructed sinus opening, fluid build up in frontal sinus and maxillary sinus
What are nasal sprays effective for decongestion?
-Local delivery, systemic absorption, easily absorbed into blood stream after by[assed mucus
What is the main barrier to nasal sprays being effective?
-Mucus layer
What is the interactive barrier?
-Drug molecules trapped in the mucus network
What is the steric barrier?
-Drug molecule cannot infiltrate mucus network
What are the functions of the mucus ?
-Clearance and air conditioning to prevent drying out
What are the features of mucus?
-From serous glands and goblet cells, form viscous gels due to mucins and have ability to form disulphide bridges
What are the types of nasal sprays?
-Steriod, anti-histomine, anticholinergic, saline, menthol and intranasal peptides
Why are intranasal peptides effective ?
-Administered nasally to avoid proteins being broken down by enzymes in the stomach
How do you use nasal sprays?
-Blow nose, shake bottle, block one nostril, insert applicator to other nostril and squeeze pump, repeat process for the other nostril
What does benztdamine do?
-Exerts an anti-inflammatory and analgestic action
What are the symptoms of oral thrush?
-Mouth is red with white patches, when you wipe the white patches away they leave red spots that bleed
Treatment for oral thrush?
-Daktarin or nystan (POM)
What are the symptoms of a mouth ulcer?
-Red/yellow sore that usually appears inside the mouth, on the cheeks or lips
What is the treatment for mouth ulcer?
-Bonjela-antiseptic and pain relief
What is otitis ?
-Inflammation in the ear resulting in the narrowing of the ear canal
What are the symptoms of excessive ear wax?
-ear pain, ringing, hearing loss, discharge, dizziness, odour
How can excessive ear wax be treated?
-Ear drops 3-4 times daily for 3-5 days
When do you refer to ENT for excessive ear wax?
-If difficulty persists despite olive oil, uncertainty about condition of ear drum
What are the types of ear drops?
-Alcohol/acetic acid, antibiotics, anaesthetics, corticosteroids
How do you use ear drops?
-Lay on towel with affected ear up, gently pull earlobe out and up to straighten auditory tue, administer drop, gently push on ear flap to encourage liquid into ear, stay for 2 mins
What are the types of eye drops ?
-Artificial tears, antibiotic, corticosteroid and glaucoma
How do you administer eye drops?
-check expiry date and shake bottle if necessary, wash hands before open, lie or sit or sit downing tilt head back, make a fist and use a knuckle to pull lower lid down and look up, squeeze one drop into lower lid, close eyes and press gently on inner corner to absorb
How do you use a pMDI inhaler?
-Remove cap, check dose counter, hold inhaler upright and shake, breathe out gently away from inhaler, put mouthpiece between teeth and deal lips, start to breathe in slowly and press down canister at the same time, continue to breathe in slowly and deeply, hold breath 5-10 s and remove inhaler from mouth, breathe out gently, repeat if needed and replace cap
What are the two routes of pulmonary drug delivery ?
-Local or topical and systemic application via the lung
How are drugs delivered to or via the lungs?
-Solid in gas, liquid in gas, gas
What types of obstructive lung disease?
-Asthma, COPD, cystic fibrosis
What are the types of restrictive lung disease?
-Interstitial lung disease such as pulmonary fibrosis, sarcoidosis obesity
