Wk 13 - Opiods Flashcards
Opiods MOA
Opioids bind mu and kappa receptors in the brain
- “Centrally acting”
- Mimic effects of endorphins
- Reduce sensation of pain as well as psychological or emotional aspect of suffering
- Raises patient’s bar for sensitivity to pain, so patient is indifferent to perceived pain
Opiods Clinical Use
- Used to treat moderate to severe pain
* Often combined with peripherally acting analgesics for their anti-inflammatory effects
Opiods Adverse Effects
• Chronic use has high abuse potential
o Addiction and dependence
• Dose dependent
o Increased dose has more analgesic effect, but also more side effects
o Fatal overdose is possible
• Variable tolerance with incomplete cross tolerance
Major Side Effects: • Pupillary miosis • Drowsiness/dizziness • Nausea/constipation o Opioids slow peristalsis in the gut • Breathing difficulty and respiratory depression
Controlled Substances Act 2014
Designated max of 325 mg acetaminophen in combination medicines
• Acetaminophen is #1 cause of liver failure
• 63% of acetaminophen overdoses were caused by acetaminophen/hydrocodone combination drugs
Hydrocodone changed from schedule III to schedule II
Tramadol changed from unscheduled to schedule IV
Tennessee Prescription Safety Act of 2012
• Passed to reduce overdosing and enabling of misuse or abuse and to identify patients with substance abuse problems
• Doctors Rxing scheduled drugs must check the Controlled Substance Monitoring Database prior to writing a new Rx
o New Rx’s must also be submitted to the database
Morphine
Gold standard/prototype opioid
Schedule II, FDA Category C
= High potential for abuse and addiction
Side effects: miotic pupils, constipation
Inappropriate for outpatient settings
Codeine
Schedule III, FDA category C
Prodrug of morphine
o Activated to morphine by cytochrome P-450 system in liver and intestines
Modest analgesia with moderate sedation
o Onset 20 min
o Max effect 60-120 min
• Extremely low abuse potential
Side effects o Pupil miosis, transient myopia due to induced accommodation o Sedation o GI upset o Some ceiling effect
Codeine Dosing
Adults: 7.5-60 mg q4-6h
• 30 mg is usual dose (Empirin/Tylenol #3)
Children 2-6 yrs: 2.5-5 mg q5-6h
• Do not exceed 30 mg in 24 hrs
• Call pediatrician first
Empirin #3,4
30, 60 mg codeine/325 mg aspirin
Dosing: 1 tab q4-6h
Tylenol #1,2,3,4
7.5, 15, 30, or 60 mg codeine/300 mg acetaminophen
Dosing: 1 tab q4h
Note that you could get the same amount of codeine Rx’ing 2 tabs of Tylenol #3 or 1 tab of Tylenol #4, but two #3’s will have double the amount of acetaminophen
Oxycodone hydrochloride
Schedule II, FDA category B
HIGH potential for abuse
Decreased side effects and increased euphoria
Congener of codeine, 10-12X more potent
o Similar painkilling effect as IV morphine
Dosing: 5-10 mg q6h
• Good painkiller, but best to avoid in eye care setting due to abuse potential/risks
Combo Formulations:
- Percocet (5 mg oxycodone/325 mg acetaminophen)
- Percodon (5 mg oxycodone/325 mg aspirin)
- Combunox (5 mg oxycodone/400 mg ibuprofen)
Hydrocodone Bitartate
Schedule II, FDA category C
Modest analgesia and mild sedation
o Milder, fewer side effects, less euphoria than oxycodone
o Derived from codeine, 6x more potent
Dosing: 5-10 mg q4-6h
Combo Formulations:
• Lortab elixer (2.5 mg hydrocodone/167 mg acetaminphen per 5mL)
• Vicodin (5 mg hydrocodone/300 mg acetaminophen)
• Lortab (5 mg hydrocodoen/325 mg acetaminophen)
• Vicoden ES (7.6 mg hydrocodone/300 mg acetaminophen)
• Vicoden HP (10 mg hydrocodone/300 mg acetaminophen)
• Vicoprofen (7.5 mg hydrocodone/200 mg ibuprofen)
• Lortab ASA (5 mg hydrocodone/500 mg aspirin)
• Zohydro (10-50 mg extended release hydrocodone cap)
o Dosing bid*
o Potential for very high dose of hydrocodone – some controversy
Tramadol (Ultram)
Schedule IV, FDA category C
Synthetic codeine analog for moderate pain
o Acts on mu receptor more than kappa
o Lower potential for abuse/addiction
No serious complications, but use caution in patients taking MAOIs
Onset: 1 hour
Dosing: 50-100 mg q4h
Max dose 400 mg/day
Combo Formulations:
• Ultracet (tramadol + acetaminophen)
Gabapentin (Neurontin)
Unscheduled, FDA category C
• Relieves pain from post-herpetic neuralgia, diabetic nerve pain, and post-op photorefractive keratectomy
o Decreases abnormal excitement in the brain – anticonvulsant
o Alters the way the body senses pain
Dosing: 300-600 mg qday-tid
o Max 1800 mg/day
Pregabalin (Lyrica)
Schedule V, FDA category C
Relieves pain from post-herpetic neuralgia, diabetic nerve pain, fibromyalgia*, and post-op lasik/PRK
Dosing: 75-150 mg qday-bid
o Max 300 mg/day
