opiods Flashcards
Mechanism of action MU (1)
Supra spinal and spinal analgesia Respiratory depression euphoria dependence constipation miosis Somatic and visceral pain
Mechanism of action Sigma (4)
Supra spinal analgesia
Somatic pain
Endocrine and behavioral effects
Pharmacologic effects
Analgesia--selective, reduced anxiety, sedation
euphoria/dysphoria
nausea--stimulate then depress the CTX
for nausea
Depresses the cough reflex
constipation
neuroendocrine -- produce less prolactin, t
trestosterone and cortisol
miosis
increased bile duct pressureDrug interactions
any CNS depressants increase depressant effects– sedation, Resp. Depression
eg. sedatives, antiemetics, anesthetics, ETOH
Respiratory Depression
In therapeutic doses
no other drugs risk is less than 1%
pain is a respiratory stimulant
caution with Chronic Resp. Disease, head injury, Higher risk in “opioid Naive”
Hypotension
If person is in supine
If person is well hydrated Low risk
–the risk if poorly hydrated, in combo with other drugs
–Postural hypotention (common)
Assist to rise slowly
Addiction
Risk is less than 1%(even with severer pain and taking Rx for extended time)
you can get:
Tolerance – requires increasing doses
Dependence – if D/C will get withdraw
symptoms
Addiction – depend and drug seeking behavior– compulsive drug use
Nursing Implications with Opioids
individualize therapy to persons needs
assess pain relief, sedation, resp. rate
**sedation precedes resp depression**
Nausea -- may need anti emetics for first
5-6 does only
Constipation -- hydrate, fiber, stool
softeners
hypotension -- hydrate
*teach to rise slowly
*Assist ambulationOverdose:
Pure, Competitive antagonist–treat acute
overdose
**Naloxone (Narcan) 1 mg. vials **
Dilute 1mg vial to 10ml (with NSS)
give in 1ml (0.1mg) increments until awake
support Resp-- O2, ventilate
given too rapid in addicted person:
severe hypertension
pulmonary edema
DEATH
Withdraw from opioids:
Abstinence
cravings restlessness, irritability increased sensitivity to pain nausea, cramps, vomiting, diarrhea muscle aches, myclonic jerk --kicking dysphoria, insomnia, anxiety pupil dilation sweating, piloerection --"goose flesh" tachycardia, elevated BP Yawning, fever
Genetic differences with Opioids
10% of codeine converted by liver to morphine10% of Caucasians don’t convert
–so codeine is ineffective
Chinese produce less morphine and are
less sensitive to morphines effects
Opioid Analgesics
Morphine (Morphine sulfate, MS)
IV, does vary widely --0.1mg/kg
individualize:
age (kids can have morphine)
weight
other medications
other illnesses --heptic metabolism
excreted renally
Watch for:
Allergy --> Histamine release
caution with asthma
sedation
nauseaOpioid Analgesics
Titrating morphine*
acute Rx-- IV
dose in 2-4 mg. Increments (adults)
wait 5-10 min. -- assess relief, re-dose
assess relief, sedation, BP, RR, SaO2
Routes:
Oral-- SR (sustained relief) up to
12 hours, SLOW ONSET
IR (Immediate Relief)
4 hours FAST ONSET
ContinuousOpioid Analgesics
Meperidine (Demerol)
IM, IV
contraindicated with MAOI antidepressant
Could cause: Hypertension, rigidity
seizure which is
SEROTONIN SYNDROME
Noreperidine Toxicity:
not for > 48 hours use
no >600 mg/day
higher risk with renal insufficiency
S/S-- irritability, muscle twitch
tremors, sizures, hallucination
Treat: D/C drug, Bensodiazepine sedative
new opioid
Half life is 15-20 hours
Mechanism of action Kappa (2)
Spinal analgesia
sedation
visceral pain
