Drug Delivery Flashcards
What are the 4 main reasons to change the route of administration for a pain medication?
If different drug profiles are needed (eg, quick acting or prolonged acting)
To avoid the 1st pass effect
To have efficient, non-invasive delivery
Patient factors (eg, age/dexterity/support)
What is an Abuse-Deterent Formulation (ADFs) of opioids?
A formulation in which the opioid is rendered useless if the tablet/capsule has been tampered with
How much more potent than morphine is fentanyl?
50-100x
Name 4 ways that a Abuse-Deterent Formulation can be made
Physcial Barrier (gel) –> Solids that become viscous when alcohol is added to extract the drug
Aversion –> Utilizes a noxious powder in the formulation to act as a deterrent
Agonist/Antagonist –> Naltrexone is added to morphine, which if chewed will be released, reducing the euphoria that is gained from the morphine
Pro-Drug –> The active drug is only avaliable once consumed
What type of fentanyl patch is Duragesic?
And what type are the newer generics?
Duragesic –> Reserviour System
Generics –> Simple adhesive-type
How can patches be abused?
Removal of the gel and boiling –> Allows the opioid to be injected or drunk
Chewing of the patch –> Released all 3 days worth via the mucosa
What is the benefit of Fentanyl Citrate?
The most lipophillic IR opioid –> so has a rapid onset of action as can pass through membranes rapidly
Can be used submucoasally as Oral Transmucosal Fentanyl Citrate (OTFC) for BTcP
What is a Copy-Number Variation (CNV)?
Either a gene deletion (loss of function) or gene duplication (increase expression and hyperactivity)
Explain the following..
Halpotype
Germline Genetic Variation
Somatic Genetic Variation
Halpotype –> A group of allelles across several genes on the same chromosome that are close together and so tend to be inherited together
Germline –> Variation of DNA that is present at conception, and so is passed down to offspiring
Somatic –> Changes in DNA that occur spontaneously after conception, and so aren’t passed down to offspring
What’s the difference between pharmacogenetics and pharmacogenomics?
Pharmacogenetics –> Study of the variability in drug response due to hereditary factors, with focus on a single gene or several genes
Pharmacogenomics –> Whole-genome application of pharmacogenetics
- Genome-wide analysis of the genetic determinants of drug efficacy and toxicity
Define Actionable Genetics
Where we could change therapy due to the genetic variability of patients (18% of US prescriptions)
What are the effects on being either a Poor Metaboliser (PM) or a Ultra Metaboliser (UM)?
PM –> ADRs at normal doses
- No/poor response to drugs that require activation (eg, pro-drugs)
UM –> No/poor repsonse to usual doses (eg, antidepressents)
- Toxicity after pro-drugs (eg, codeine)
What’s the difference between a Genotype and a Phenotype?
Genotype –> An individuals full hereditary information (“Born with it”)
- Eg, A pair of alleles regarding the CYP2D6 genotype
Phenotype –> The individuals actually expressed properties/oberservable characteristcs (eg, metabolism of tamoxifen)
Why do Poor Metabolisers (PM) get less of a benefit from tamoxifen?
Which class of drugs would be better for them?
As tamoxifen is broken down to more active metabolites….which is a slower process in PMs
They would get better outcomes by taking aromatase inhibitors
Why is genetic testing useful before giving treatment with 6-MP?
As if people have inactive forms of TPMT they cannot break down 6-MP, so the cancer therapy is toxic
Slow metabolisers will therefore need to have lower doses and shorter durations of treatment
What is the Calvert Equation?
