Drug Delivery for Pain Management in Oncology Flashcards
Why change the route or method of administration for pain management?
Different drug exposure profiles.
To avoid hepatic first pass metabolism in gastrointestinal tract
To have efficient, non-invasive delivery.
Patient factors.
What form of oral opioid products are given?
Immediate release for acute and breakthrough cancer pain.
Sustained release or controlled release for chronic pain.
What are the factors needed to be considered for sustained release or controlled release opioids for chronic pain?
Patient should already be receiving opioids and developed some tolerance.
Depending on the product, dosed every 12 or 24 hours continuously.
Provides more stable blood level PK profile.
Must closely follow patient information instruction.
Larger doses per unit are more prone to abuse.
What are the principals of dosing for pain management?
Better to schedule medication instead of waiting for pain.
Short acting given every 4 hours.
Long acting given every 12 hours.
What are abuse deterrent formulations of opioids?
Aim to render diverted opioids unusable if there is an attempt to extract the drugs.
Why is the potential for abuse of opioids high?
Because of its pharmacokinetic profile.
The pharmacodynamics of increasing Cmax and decreasing Tmax correlate with the pharmacodynamic property of euphoria.
What is the physical barrier abuse deterrent formulation strategy?
Tablet formulation with a structure which is highly viscous or semi solid.
Gel formulation limits abuse if it is deemed to difficult to overcome the delivery system.
What is the aversion abuse deterrent formulation strategy?
Utilises noxious component added to the powder formulation to discourage abuse because of unwanted adverse effects.
What is the agonist/antagonist ADF strategy?
Pellets of morphine sulphate are surrounded by a central core of sequestered naltrexone hydrochloride.
When capsules are chewed, ground or tampered with the naltrexone is released causing decrease in euphoria anticipated from opioid.
What is the pro-drug ADF strategy?
The drug is a pro-drug. GI biotransformation is the rate limiting step.
What is the abuse deterrent formulation of oxycodone?
No drug released if crushed and ingested.
Forms a viscous gel if wetted, cannot be injected.
Releases less drug if attempt to dissolve in vodka.
How are transdermal patches abused?
The gel is removed and boiled to extract the opioid.
Patches chewed to release 3 days of dose.
Multiple patches are placed on the skin.
What is the impact of breakthrough cancer pain?
Higher levels of:
Background pain, peak pain, depression, anxiety, functional impairment.
Negative effect on quality of life.
Requires an additional dose that is short acting.
What is the treatment for breakthrough pain?
Needed to taken as soon as the pain begins.
Morphine, oxycodone, hydromorphone, fentanyl.
What are the characteristics of fentanyl citrate?
Potent mu opioid analgesic with rapid onset of analgesia.
Most lipophilic of all the available immediate release opioids.
Quickly crosses the cellular barriers, providing broad tissue distribution and rapid onset of action.
