test 2 - opioids and hypnotics Flashcards
drugs included
morphine sulfate naloxone nalbuphine codeine zolpidem
prototype for narcotic class
morphine
morphine
(Schedule II)
is standard against which new analgesics are measured
action of morphine
Central action on perception of pain. Primary site is sensory cortex. Also alters attitudes by psychological, sedative, and hypnotic effects.
what receptors does morphine interact with
It is an agonist which interacts with mu and kappa receptors in brain and other tissues. Receptors are widely but unevenly distributed throughout CNS, with highest concentration in limbic system (frontal and temporal cortex, amygdala, and hippocampus), thalamus, striatum, hypothalamus, midbrain, and spinal cord.
effects morphine has on CNS
analgesia, drowsiness, changes in mood, mental clouding
a. constricted pupils (probably central action on oculomotor nerve) b. respiratory center--depresses brain stem, decreases response to CO2. (may take up to 30 min. after IM injection to see this.) c. Post-medulla-chemoreceptor trigger zone (CTZ) is directly stimulated. All clinically useful opioids produce some degree of N/V.
Effects of morphine on CV
supine, no major effects on BP, pulse rate and rhythm. Does dilate
resistance vessels, leading to postural hypotension. Most opioids provoke the release of histamine which may be cause of hypotension. Does affect cerebral vessels, too. (Do NOT use with head injury - increases intracranial pressure)
effects of morphine on GI
MAIN EFFECT IS CONSTIPATION!! SLOWS DOWN MOTILITY AND DECREASE SECRETIONS
stomach–decreases secretion of hydrochloric acid, decreases motility, increases tone in antrum and duodenum which leads to delay in gastric emptying (as much as 12 hours.) This is ½ of the cause of constipation.
b. small intestine–decreases biliary and pancreatic secretions, may increase non-propulsive contractions, decreases propulsive contractions markedly. Upper small intestine is affected more than lower. This is ¼ of constipation problem.
c. large intestine–decreases or abolishes propulsive contractions, increases tone to point of spasm, increases tone of sphincter. This is ¼ of constipation problem.
d. biliary tract–marked increase in biliary tract pressure which leads to spasm.
effects of morphine on smooth muscle
ureter–increases tone and amplitude of contractions of ureters, especially lower 1/3
b. bladder–increases tone leading to urgency. Increases tone of sphincter leading to retention
c. uterus–prolongs labor; male-decreases libido
d. bronchial–large doses lead to bronchoconstriction
effects of morphine on skin
therapeutic doses cause cutaneous blood vessels to dilate–leading to flushed and warm face, neck and upper thorax. (may be due to release of histamines–also reason for pruritus and sweating.)
pharmacokinetics of morphine
Absorption–readily absorbed from GI tract but does have “first-pass” phenomenon in liver. Also absorbed from sub-cu and IM routes.
Distribution–rapid and wide. 1/3 is bound.
Metabolism–in liver
Excretion–by kidney, especially by glomerular filtration of metabolites
dosage of morphine for adult/child
adult: 5-15 mg q4h
child: 0.1-0.2 mg/kg/dose
ADRs of morphine
can readily see from effects under action.
can have allergic - skin rashes, edema. Tolerance, ABUSE!
different types of opioids
meperidine (demerol) percocet percodan vicodin and norco dilaudid
meperidine (demerol)
(Schedule II) is synthetic
GI effects are less, so less constipation and less biliary spasm; also less urinary retention; and less effect on uterus.
causes hypotension; good for rigors or post-anesthesia shivering; is not good for cough and diarrhea
Effects are additive; and don’t last as long; is also protein bound (40-60%); 50% escapes “first pass”
percocet (oxycodone and acetaminophen)
schedule 2
percodan (oxycodone and aspirin
Oxycodone is a derivative of Morphine. Is 5-6 times more potent than Codeine
vicodin and norco
hydrocodone and acetaminophen
schedule 2
dilaudid
hydromorphone
schedule 2
Naloxone (narcan) classification
narcotic antagonist
action of naloxone
Is a “pure” antagonist, with no agonist or resp. depressant effects. Blocks opioid receptor
pharmacokinetics of naloxone
Absorption: Oral–good, but “first pass” extensive (1/50th as potent as IV)
Distribution: IV–onset 1-2 min; SC/IM – 2-5 min; duration 1hr (IV); crosses placenta.
Metabolism: liver
ADR of naloxone
will cause withdrawal symptoms if addicted to opioid
dosage of naloxone for adult
0.01 mg/kg
usually 0.8 is usual dose for adult IV
Special information of naloxone
Used to reverse narcotics effects of anesthesia, or in cases of overdose.
buprenorphine/naloxone – Suboxone/Subutex, is used for treatment of opioid dependence. Buprenorphine is a partial opioid agonist – combined with naloxone to avoid a “high.”
naltrexone
naltrexone
ReVia, is used for alcohol dependence/withdrawal as well as opioid-dependent clients.
Nalbuphine (nubain) classification
narcotic-agonist-antagonist
action of nalbuphine
Combines with kappa receptors producing analgesia.
Also acts as a partial antagonist at mu receptors.
pharmacokinetics of nalbuphine
Absorption: IM good; oral only 20% as potent as IM Can also be given SC or IV
Distribution: Onset 15 min. Duration 3-6 hr.
Metabolism: Liver
Excretion: Kidney
ADRs of nalbuphine
Sedation, sweatiness, clamminess, N/V, dizziness, vertigo, dry mouth, headache, resp. depression.
dose of nalbuphine
10mg/70kg
special information of nalbuphine
Can be reversed by Narcan
2. Has low abuse potential 3. Also, buprenorphine
codeine classification
Narcotic analgesic – oral; antitussive also
action of codeine
Binds to opioid receptors and produces mild to moderate pain relief.
Converted to morphine when metabolized. Some individuals are “ultra- rapid” converters – who then achieve dangerously high morphine levels.
pharmacokinetics of codeine
Absorption– readily oral (rarely given IV, IM, or subcu)
Distribution–
Metabolism– liver; 10% of dose is converted to morphine
Excretion– metabolite is slowly excreted by kidney
adrs of codeine
respiratory depression, constipation, urinary retention, and miosis, though less than with morphine
dosage of codeine
Adults – 15-60 mg every 3-6 hours (max 120 mg/24 hr)
Children >1 yr. = 0.5 mg/kg every 4-6 hours (max 60 mg/24 hr)
special information of codeine
- Requires higher dosing to achieve pain relief – side effects can be significant as dosing rises.
- Can be an effective cough suppressant – but dose lower (10 mg)
- 200 mg po codeine = 30 mg po morphine
zolpidem (ambien) classification
Hypnotic, non-BZD (benzodiazepine)
action of zolpidem
Binds to benzodiazepine receptors in the brain.
pharmacokinetics of zolpidem
Absorption: rapidly absorbed from GI tract (given orally)
Distribution: peak concentration in 1-2 hours; half-life prolonged in elderly and those with hepatic dysfunction.
Metabolism: liver.
Excretion: urine, bile, feces.
adrs of zolpidem
dizziness, headache, nausea, diarrhea, next-day drowsiness (only 1-2 %); higher incidence of ADRs with higher dosages (esp. > 20mg). Sleep driving, and other sleep-related behaviors also seen.
dosage of zolpidem
5-10 immediately before bedtime (rapid onset)
special information regarding zolpidem
- Acts like a benzodiazepine but is structurally different.
- *In January 2013, dosages were lowered (essentially cut in half); 5 mg for women, and 5-10 mg for men.
- Short-term treatment not associated with withdrawal symptoms, tolerance, or dependence.
- Ambien CR – is extended-release formula; also orally disintegrating tablets, oral spray, and sublingual tablets
- Classified as Schedule IV
- Also zaleplon (Sonata) and eszoplicone (Lunesta)
(the “z” drugs).
