opioid tx, AE, monitoring

Question 1

Which opioids are short acting?

Answer 1

• oxycodone
• hydrocodone
• oxymorphone
• hydromorphone

acute/breakthrough; opioid naïve patientsfEn

Question 2

Which opioids are long-acting?

Answer 2

• oxycontin
• MS contin
• fentanyl
• methadone

maintenance tx; more stable pts

Question 3

Fentanyl

Answer 3

most common is patch

• rotate application site (upper arms & chest)
• do not apply heat

NEVER for opioid naïve pts

Question 4

Tramadol

Answer 4

partial mu, 5HT abilities (C-IV)
not for chronic use
- may decr. seizure threshold

Question 5

Tapentadol

Answer 5

mu agonist, NE reuptake

• no hepatic/renal dose adj.
• addictive potential

Question 6

Tapentadol AE

Answer 6

• constipation
• respiratory depression
• N/V
• dizziness

Question 7

Methadone

Answer 7

Mu, kappa, delta; SSRI/SNRI, NMDA activity

no renal monitoring (inactive metabolites)

*FAR LESS EUPHORIA than oxycodone or morphine

• low dose/high potency
• quick onset, long acting
• ONLY long-acting liquid
• OKAY with gastric bypass pts

Question 8

Methadone baseline checks

Answer 8

can prolong QTc & cause Torsades
- baseline EKG on everyone (@ 1 mo, 6 mo, then yearly [as long as no dose incr])
< 450 = safe
450 - 499 = monitor closely
> 500 = avoid use/decr. dose

*watch with other QTc incr. meds
(ANTI: -biotics, -fungals, -virals, -malarials, -psychotics, -depressants, -histamines)

Question 9

Methadone metabolization

Answer 9

CYP3A4

inhibition = decr. 25%

• azole antifungals
• amiodarone
• erythromycin

induction = start c/ calculated & slowly incr.
- rifampin
- carbamazepine
- phenytoin
(can take 1-2 wks after starting a certain agent)

Question 10

Who should we avoid methadone in?

Answer 10

• poor/limited prognosis (dose adj. take too long)
• non-adherence PMH
• EXCESSIVE FATIGUE OR SEDATION
• elderly that live alone
• QTc > 500

Question 11

Methadone counseling tips

Answer 11

• SEDATING
• must be very adherent
• no dose adj. on your own
• 5-7 days before a full response

just give naloxone

Question 12

How do we start someone on methadone?

Answer 12

HARD CHANGE
- all other opioids should be stopped (continue short acting if not accounted for in calculation)

• follow up call in 1 week

Question 13

Methadone: follow up/monitoring

Answer 13

• status check phone call min of 1 week
  (they should call sooner if AEs)
• incr. dose 25-50% @ 1 week

EKG @ 1 mo

Question 14

General AE of opioids:

Answer 14

• N/V
• RESPIRATORY DEPRESSION
• CONSTIPATION*
• Euphoria

pts will get used to everything EXCEPT constipation*

morphine & related prods:
- itching/rash
(histamine based rxns, NOT ALLERGY)
–> treat c/ antihistamine

Question 15

What agents have similar structure to morphine?

Why do we care?

Answer 15

oxycodone, hydrocodone

–> if true morphine allergy we should avoid the similar structure agents

(OK to use fentanyl, methadone, tapendatol, tramadol)

Question 16

treating AE of opioids

Answer 16

N/V
- antiemetics

Constipation

• laxative (senna, bisacodyl [stimulant]; miralax powder [osmotic])
• Stool Softener (docusate)

Respiratory depression
- naloxone

• we really should be giving everyone getting an opioid naloxone and a laxative

Question 17

What is opioid induced hyperalgesia?

Answer 17

nociceptive sensitization caused by opioid exposure
- pt on opioids can become more sensitive to pn stimuli!

*reason we see loss of efficacy in some

caused by opioid metabolites agonizing NMDA receptors
- morphine (M3G agonizes NMDA); glucoronidation vs CYP

• we stop hyperalgesia by stopping current opioid & using NMDA antagonist (ketamine, dextromethorphan, memantine, amantadine)
  opioids: methadone, dextropropoxyphene, ketobemidone

Question 18

What can urine drug screens check for?

Answer 18

• amphetamine (pseudophed, ADHD meds, crystal meth)
• barbiturate (Fioricet)
• BZDs
• Cocaine
• Marijuana
• Methadone
• Opiate (codeine, morphine, hydrocodone, hydromorphone, heroin)
• Oxycodone
• fentanyl must be special ordered