D. Formulations for analgesics Flashcards
Where do you ideally want the plasma concentration to fall after administration of a single dose of immediate release tablet?
Therapeutic window
What would happen if plasma concentration of an oral dose is over the minimum toxic concentration (maximum safe concentration)?
Patients would experience many side effects
What would happen if plasma concentration relation of oral dose is below minimum effective dose ?
No effect
What issues would arise if a patient was given multiple dosing regimens as a method of receiving treatment ?
- Drug plasma only maintained within the therapeutic window for SHORT time intervals
- LONG time intervals with patients being under-medicated (below minimal effective concentration). This could lead to patient experiencing pain.
What assumptions would need to be taken into consideration for patients receiving multiple dosing regimens ?
- Constant drug dose
- Constant time intervals
- Constant apparent absorption rate
- Constant apparent elimination rate
How could you avoid plasma concentrations falling below the therapeutic window ? How can we maintain plasma concentrations of drug within the therapeutic window ?
Dose at shorter time intervals
What are the with giving dose at shorter time intervals ?
Decreases patient compliance as the drug has to be taken more often than normal. They may forget
What are extended release tablets designed to do ?
Prompt achievement of plasma concentration of drug:
A. remains constant value within the therapeutic range for a satisfactory amount of time
B. Declines at a slow rate within the therapeutic window
What does MSC and MEC mean ?
Maximum safe concentration
Minimum effective concentration
What population of people are dispersible tablets useful for?
Patients who have difficulty swallowing
How does dispersible tablets work ?
Drop tablet into a glass of water
Reaction of carbonate/bicarbonate with a weak acid (citric acid)
Why are dispersible tablets absorbed faster than normal?
They have a fast disintegration and dissolution
They increase the pH of the stomach, meaning that emitting time is faster and has a short residence time in the stomach.
This means they can reach the intestine quicker, which is the site of absorption. And has a rapid onset of action.
They also avoid gastric irritation
What population of people are suspensions and fast dissolving oral delivery systems useful in ?
Paediatric
