Opioids Flashcards
what are narcotics
- ‘opioids’ = any natural or synthetic drug that has morphine-like pharmacological action
- major effects of opioids are on CNS and bowel
what binding sites are called the opiate receptors (for opioids to act as agonists) in the CNS
- mu
- delta
- kappa
what are pure agonists (opioids)
- activate both Mu and Kappa receptors
- strong or moderate in producing an analgesic (relief of pain) effect
- ex. morphine
what are mixed agonists-antagonists (opioids)
- activate Kappa receptors but block Mu receptors
- analgesic (relief of pain) effect with some antagonist activity
- ex. pentazocine (talwin)
- butorphanol (stadol)
what are pure antagonists/blockers (opioids)
- inhibit both Mu and Kappa receptors
- no analgesic effects; used in opioid overdose
- ex. naloxone, naltrexone (revia)
what are some opiate agonists with moderate efficacy
- codeine
- hydrocodone (hycodan)
- oxycodone (oxycontin)
- combined with acetaminophen = Percocet
- combined with ASA = percodan
what are some opioid agonists with high efficacy
- hydromorphone (dilaudid)
- meperidine (demerol)
- morphine
what are some other effects of opioids besides analgesia
- suppress cough reflex
- slow GI motility
- depress CNS
- sedation
- euphoria
what are some adverse effects of opioids on the CNS
- respiratory depression
- cough suppression
- nausea/vomiting
what is an adverse effect of opioids in the GI tract
- constipation
what are some other adverse effects of opioids in general
- tolerance can develop
- physical and psychological dependence
what drugs will interact poorly with opioids
- antihistamines, sedative/hypnotics, alcohol and psychotropics
- increased CNS effects (e.g. sedation)
at what dose will morphine reduce severe pain or eliminate pain
- 5-10 mg
what are the central actions or morphine (and some other opioids)
- analgesia
- drowsiness and sleep
- cough suppression
- vomiting (due to stimulation of chemoreceptor trigger zone in the brain)
- hypotension
- miosis (papillary constriction)
- respiratory depression (high doses): major toxic effect and cause of death because no tolerance is developed to respiratory depression
- euphoria (ecstacy; develop tolerance rapidly to euphoric actions)
- increased release of ADH (antidiuretic hormone), which causes urinary retention
what are some other minor activities (peripheral actions) caused by morphine and some other opioids
- constipation (due to slowing of peristalsis)
- body warmth/flushing/itching (due to histamine release)
when is morphine used
- severe pain due to trauma, cancer, or heart attack
- severe and chronic pain
- pre-anaesthetic medication
what does morphine do (pharmacodynamically)
- binds with mu and kappa receptor sites
- analgesia, euphoria, constriction of pupils, stimulation of cardiac muscle
- relieves SOB with heart failure and pulmonary edema
- for relief of chest pain due to heart attack
what are some side effects of morphine
- dysphoria (restlessness, depression, anxiety)
- hallucinations
- nausea
- constipation
- dizziness
- itching sensation
- in cases of overdose, respiratory depression, cardiac arrest
- do not take with alcohol -> both are CNS depressants
- tolerance and cross tolerance can develop, as well as physical and psychological dependence
what is methadone
- long-acting synthetic morphine derivative used orally in the treatment of opioid (usually heroin) addiction
- used to ‘wean’ patients off narcotics because it does not produce euphoria
- it is still abused
what is meperidine
- also called demerol
- less effective analgesic than morphine with half the duration of action (75 mg meperidine IM = 10 mg morphine IM)
- used for moderate to severe pain
what is oxycodone and hydrocodone
- semisynthetic morphine derivatives
- respiratory depression, antitussive, constipation and dependence
- moderate to severe dental pain
- it is most effective when combined with NSAIDs, aspirin, or acetaminophen (eg Percocet, percodan)
what is codeine
- naturally occurring narcotic agonist obtained from the opium poppy but in lesser amounts than morphine
- less potent analgesic than morphine (120 mg of codeine phosphate IM = 20 mg morphine IM; 200 mg codeine oral = 30-60 mg morphine orally)
- less respiratory depressant and constipation and has less dependance potential
what type of drug is codeine
- prodrug (its analgesic activity is the result of a conversion to morphine by cytochrome P450 liver enzymes)
- usually combined with other non-narcotic drugs such as acetaminophen (Tylenol) for the relief of acute nociceptive mild to moderate dental pain
- also used as an antitussive in cough syrups
dental hygiene guidelines for patients taking codeine
- monitor patient for dry mouth; fluoride rinses if indicated
- monitor vital signs due to effects on the heart and respiratory system
- causes drowsiness/sedation
what is propoxyphene
- also called Darvon
- related to methadone with less analgesic activity than codeine
- abused
what is destromethorphan
- agonist opioid without any analgesic activity
- high antitussive effects (used in cough medicines)
what is loperamide
- agonist opioid without analgesic effects
- increases smooth muscle tone in the GI tract and is used as an antidiarrheal
what is diphenoxylate
- agonist opioid/anticholinergic
- antidiarrheal
- combined with atropine in a product called lomotil (can cause severe respiratory depression, coma and death after overdose in children)
what is tramadol
- also called ultram
- agonist, unique analgesic quality having both opiate and central acting adrenergic qualities
- not a controlled substance; not narcotic
- approved for moderate to moderately severe pain
- can cause serious neurotoxicity and is not the first-line drug of choice
what is naloxone
- opioid antagonist
- block both mu and kappa receptors
- complete or partial reversal of opioid effects
- reverse opioid symptoms of respiratory depression and CNS depression within minutes
what are some side effects of naloxone
- rapid loss of analgesia
- increased blood pressure
- tremors
- hyperventilation
- nausea/vomiting
- drowsiness
what are signs of withdrawal
- chills, abdominal and muscle cramps
- severe itching, sweating, restlessness
- anxiety, yawning, drug-seeking behaviour
what is substance abuse
- the use, by self-administration, of a drug that does not conform to the medical or social norms within the client’s given culture or society
what are some reasons for substance abuse
- increase performance
- assist in relaxation
- alter psychological state
- fit in with the crowd/peer pressure
what are the 3 structures of society substance abuse has an impact on
- economic, social and public health
what are some legal substances that are often abused
- alcohol
- nicotine
- volatile inhalants (aerosols, paint thinners)
- narcotics
- marijuana
what are some illegal substances that are often abused
- stimulants
- hallucinogens (LSD, PCP, psilocybin aka magic mushrooms)
- narcotics
what is addiction
- an overwhelming feeling to take
- continued use of a substance despite its negative health and social consequences
- legal prescription drugs rarely cause addiction
what is dependence
- overwhelming desire to take drug and cannot stop
- 2 types: physical, psychological
what is physical dependence
- the condition of experiencing unpleasant withdrawal symptoms when the substance is discontinued
- altered physical condition caused by the nervous system adapting to repeated drug use
- withdrawal symptoms when discontinued
what are some drugs that can cause physical dependence
- narcotics
- alcohol
- CNS depressants
- some stimulants
- nicotine
what is psychological dependence
- an unpleasant intense craving for a drug after it has been withdrawn
- no physical signs
what are some drugs that can cause psychological dependence
- marijuana
- anti anxiety drugs
- crack cocaine
what is classic withdrawal
- unpleasant symptoms experienced when a physically dependent client discontinues use of an abused drug
- prescription drugs used to reduce severity of symptoms
what is conditioned withdrawal
- environment and social contacts contribute to relapse after addict is no longer abusing substance
- treatment: stop association with past social contacts or relationships
what is tolerance
- the individual adapts to the drug over time
- higher and higher doses needed to produce the same initial effect
- common with drugs that affect the nervous system
- does not develop at the same rate for all actions of a drug
