Opioid Analgesics Flashcards
Diarrhea
- Loperamide
2. Diphenoxylate
Maintenance programs for heroin addicts
- Methadone
2. Buprenorphine + naloxone
Mechanism of opioid analgesics
Agonists at opioid receptors (mu = morphine, delta = enkephalin, kappa = dynorphin); decrease synaptic transmission by opening K+ channels and closing Ca2+ channels
Signs/symptoms of opioid toxicity
- Respiratory depression
- Constipation
- Miosis (pinpoint pupils)
Rx for opioid toxicity
Naloxone or naltrexone (opioid receptor antagonists)
Butorphanol mechanism of action
Kappa-opioid receptor agonist and mu-opioid receptor partial agonist; produces analgesia
Clinical uses of butorphanol
Severe pain (e.g., migraine, labor).
What is one advantage of using butorphanol?
Causes less respiratory depression than full opioid agonists.
What is two disadvantages of using butorphanol?
- Can cause opioid withdrawal symptoms if pt is also taking full opioid agonist.
- Overdose not easily reversed with naloxone.
Tramadol mechanism of action
Very weak opioid agonist; also inhibits 5-HT and norepinephrine reuptake
Clinical use of tramadol
Chronic pain
Tramadol toxicity is…
Similar to opioids. Decreases seizure threshold. Produces serotonin syndrome.
Signs/symptoms of opioid intoxication
Euphoria, respiratory and CNS depression, decreased gag reflex, pupillary constriction (pinpoint pupils), seizures (overdose)
Signs/symptoms of opioid withdrawal
Sweating, dilated pupils, piloerection (“cold turkey”), fever, rhinorrhea, yawning, nausea, stomach cramps, diarrhea (“flu-like” symptoms)
Methadone is…
A long-acting oral opiate used for heroin detoxification or long-term maintenance.
