Opioid Treatment

Not approved for clinical use!

Heroin

strong opioid agonist

more lipid soluble and faster acting than morphine

euphoria

Phycial Dependence tx

Buprenorphine

in addition to analgesia, also tx opioid addiction

safer and as effective as methodone

also used to tx depresion and in smoking cessation programs

Methodone

strong opioid agonist

oral

long duration, so less severe withdrawal syndrome

also has good analgesia for cancer and neuropathic pain

cross tolerance decreases heroin's reinforcing properties

no euphoria

Overdose tx

both are pure competitive opioid antagonists --> can preciptate opioid withdrawal

(oral)

Naltrexone

to dx opioid dependence

can also reduce craving for alcohol

Naltrexone + Clonidine or Buprenorphine = rapid opioid detox

(IV)

Naloxone

to reverse opiod overdose and toxicity

short duration of action (so you need to maintain vigilance around the patient - they might go back into opioid-induced respiratory depression)

only partially reverses tramadol

doesn't reverse pentazocine or buphrenorphine at all

LOW dose

Dyspnea

for dyspnea associated with acute pulmonary edema secondary to acute left ventricular failure

morphine's ability to relieve SOB is due to:

1) decreased peripheral RESISTANCE

2) slowing of RESPIRATION

3) relief from ANXIETY

Diarrhea Suppression

Loperamide

weak opioid agonist

minimal dependence risk

poorly absorbed

doesn't cross BBB

Diphenoxylate (+ atropine)

weak opioid agonist

minimal dependence risk

combined with atropine to decrease misuse by IV route

Cough Suppression

Dextromethorphan

less constipating than codeine

no analgesic activity

no dependence risk

dizziness

nausea

overdose: seizures

HIGH dose

Anesthesia

very high dose

less constipating effect than codeine

no analgesic activity

no dependence risk

AE:

dizziness

nausea

drowsiness

Analgesia

moderate pain

Buphrenorphine

Pentazocine

for moderate pain (has analgesic ceiling)

resistant to naloxone reversal

hallucinations

anxiety

dysphoria

may increase BP

CONTRAINDICATED FOR MI's

neuropathic pain

Tramadol

for neuropathic pain

enhances 5-HT and NE neurotransmission by blocking reuptake (makes you happier)

actions partially reversed by naloxone

NO effect on respiration

increased risk of seizures

CONTRAINDICATED IN PATIENTS WITH EPILEPSY OR PATIENTS TAKING MAOI'S (lower seizure threshold)

Meperidine

strong opioid agonist

no effect on cough reflex

largely replaced by other opioids

w/ MAOI

"serotonin syndrome"

severe restlessness

excitement

fever

seizures

delirium

midriasis

d/t weak anticholinergic activity

note: this is OPPOSITE from what you would expect with an opioid!

vomiting

less than with morphine

Overdose: CNS excitation, seizures

due to formation of N-demethylated metabolite (normeperidine) -- no analgesic activity

Codeine

weak opioid agonist

also Oxycodone, Hydrocodone, Dihydrocodeine

gets its analgesic activity from conversion to morphine (10% is converted)

good oral bioavailability (unlike morphine)

less respiratory depression than morphine

hydrocodone + acetaminophen = Vicodin/Lortab

oxycodone + acetaminophen = Percocet

oxycodone + aspirin = Percodan

less than morphine

preanesthetic

Fentanyl

strong opioid agonist

rapid onset, short duration

100x more potent than morphine

used during labor, as preanesthetic, and for pre-, intra-, post-op, & breakthru pain

can use for "balanced anesthesia" (ie to supplement the analgesia and sedative-hypnotic effects of NO and halothane)

Fentanyl + droperidol = Innovar (induces neuroleptanalgesia, permitting wakeful state when cooperation is needed during surgery)

can be given in transdermal patch or lollipop for breakthru pain

minimal constipation

minimal respiratory depression

minimal cardiac depression

severe musc. rigidity

on rapid IV administration

Morphine

strong opioid agonist

undergoes significant first pass metabolism when taken orally

drug interactions

drugs that add to sedation or cause respiratory depression

w/ SSRI, MAOI, or TCA (incr. serotonin)

cause "serotonin syndrome"

AE:

other

pruritis

prolonged labor

GI/Kidney/Gallblader

increased tone

painful biliary spasm

painful urine retention

constipation

postural hypotension

CNS

miosis

= constriction

exception: Meperidine

pneumonia

tolerance & dependence

N/V

drowsiness

respiratory depression

Opioid Treatment