week 7- Analgesic Agents and Anti-inflammatory Agents Flashcards
Analgesics
Medications that relieve pain without causing loss of consciousness
Pain has two element—
physical and psychological
Classification of Pain
Somatic-originates from skeletal muscles, ligaments & joints
Visceral-originates from organs and smooth muscles
Superficial-originates from the skin and mucous membranes
Vascular-originates from vascular or prevascular tissue. Maybe responsible for migraine headaches
Referred-result of visceral nerve fibers synapse firing in the spinal cord which are close to other nerve fibers supplying tissue in the body
Neuropathic-results from injury or damage to peripheral nerve fibers or damage to the CNS. Not disease process due to injury.
Phantom-occurs in a body part that has been removed surgically or traumatically. Characterized as burning, itching, tingling or stabbing pain.
Cancer-pain due to pressure on nerves, organs or tissue. Hypoxia to an organ, circulatory blockage to an organ, metatasis, muscle spasms, side effects of chemotherapy, radiation or surgery
Psychogenic-originates from psychological issues, not physical.
Central-due to tumors, trauma or inflammation of the brain
2 types of nerve fibers
Fiber A-
have myelin sheaths, large fibers, fast speed conduction pain, sharp and localized
A-controls the closing of the gates which blocks or inhibits impulses from traveling to the brain
Fiber C-
have no myelin sheaths, small fibers, slow conduction speed with dull, non localized pain
controls the opening of the gates which allows impulses to travel to the brain therefore perceiving pain
Posterior dorsal horn is where the
pain fibers enter the spinal cord.
Opioid Analgesics
Narcotics: very strong pain relievers
mech of action for opioids
Opioids bind to opioid receptors in the brain which causes an analgesic response therefore reduces pain
Can be partial agonists causing limited response by binding to the pain receptors and producing very minimal or no responses
The endorphins are the own body’s mechanism
in response to pain. They are the pain killers in our system
Opioid receptors
MU –analgesia, respiratory depression, euphoria, sedation
KAPPA-spinal analgesia, sedation, miosis
DELTA-analgesia
Opioid Analgesics used in adjuct with
NSAIDs
Antidepressants
Anticonvulsants
Corticosteroids
besides pain, Opioids are also used for:
***Cough center suppression (DM or codeine)
Treatment of diarrhea (Imodium)
Balanced anesthesia (Fentanyl)
**Opioid analgesics mainly work with the CNS and brain but can also have some effects outside the CNS.
Opioid Analgesics: Side Effects
Euphoria (initially) ***CNS depression Respiratory depression Nausea and vomiting Hypotension (vasodilation) Urinary retention (increased bladder tone) Diaphoresis and flushing (vasodilation) Pupil constriction (miosis) ***Constipation (decreased gi motility) Itching (histamine release)
Narcan-
antidote which competes at the binding sites (has a higher affinity to the receptors thereby reverses symptoms). Antagonist at all opioid receptor sites in the CNS Mu KAPPA Delta. Given IM, SubQ, IV
Toradol/Tramadol/Tramacet:
new drug of choice for pain control for those individuals who may use, misuse or abuse narcotics
Non-opioid Analgesics:Acetaminophen
Analgesic and antipyretic effects
Little to no anti-inflammatory effects
Available OTC and in combination products with opioids
(((Blocks peripheral pain impulses in the CNS
Antipyretic effects from direct activity on the hypothalamus )))
USED FOR:Mild to moderate pain AND Fever
OVERDOSING ON ACETAMINOPHEN
Overdose, causes hepatic necrosis
Long-term ingestion of large doses also causes nephropathy
NAC (N-acetylcysteine) antidote
–prevents hepatotoxic metabolites from forming
FOR ACETAMINOPHEN
ACTEAMINOPEN SHOULD NOT BE TAKEN IF
Liver dysfunction
Possible liver failure
When taking other hepatotoxic drugs
Dangerous interactions may occur if taken with alcohol
Other Non-Opioid Analgesics:NSAID
– (non steroidal anti-inflammatory drugs) ie Ibuprofen, Advil, Motrin, Aleve, Diclofenac
adverse effects are GI intolerance, bleeding, and kidney impairment.
they have a ceiling effect
Other Non-Opioid Analgesics: Muscle Skeletal Medications
– Methacarbomal – Robaxisal, Robaxacet
Other Non-Opioid Analgesics: Acetylsalicylic acid
– Aspirin, ASA, Entrophen
Other Non-Opioid Analgesics: Corticosteroids
- Prednisone
Other Non-Opioid Analgesics: Topical Anaesthetics
– Lidocaine, Benzocaine, Emla
Other Non-Opioid Analgesics: AllopurinoL
- reduces the production of uric acid- uric acid buildup can lead to gout or kidney stones. Maintenance drug
Other Non-Opioid Analgesics: Colchicine
- responds to uric acid crystals, which reduces swelling and pain for gout. Acute episodes. Very narrow therapeutic window – overdose can lead to generalized organ failure.
Other Non-Opioid Analgesics: Glucosamine
- naturally occurring sugar protein found in bones, bone marrow that helps build cartilage (the hard connective tissue located mainly on the bones near your joints). Supplemental therapy
Other Non-Opioid Analgesics: Chondroitin
- naturally occurring substance formed of sugar chains.It helps the body maintain fluid and flexibility in the joints.Used in alternative medicine as a possibly effective aid in treating osteoarthritis pain
Opioid Analgesics: Nursing Implications
Constipation is a common side effect to opioids and may be prevented with adequate fluid and fiber intake
Patients should be instructed to change positions slowly to prevent possible orthostatic hypotension
Drugs in the Opioid family
Opium Heroin Codeine Hydromorphone (long acting) Meperidine (Demerol) Morphine Oxycodone (long acting) Oxycocet (combination of codeine and acetaminophen) Propoxyphene (Darvon)
CLASSES OF OPIODS
Opium and heroin are Schedule I agents
(schedule F in Canada): This is due to the very high dependency rate. (Controlled Drugs
Heroin
Causes a brief “rush,” followed by a few hours of a relaxation, content state
In large doses opioid can cause respiratory arrest
They block the receptors in the CNS thereby blocking the sensation of pain
Imodium (Loperamide) –
used for diarrhea
Codeine –
used for pain, cough and sedation
Dextromethrophan (DM) –
used as a cough suppressant
Fentanyl Patches –
used for severe, chronic or terminal pain
Pentazocine (Talwin) –
frequently used post-op but now Morphine and Demerol are more popular
Opioid Drug Withdrawal
Peak period: 1 to 3 days after the drug is withdrawn
Duration: 5 to 7 days
Signs & Symptoms Drug seeking, intense desire for drugs, cravings Mydriasis, lacrimation Diaphoresis Rhinorrhea Muscle cramps Nausea, vomiting, diarrhea Hypertension, tachycardia, Anxiety, restlessness
Opioid Drug Withdrawal Treatment:
Narcan is the specific antidote - used in situations of respiratory distress
Opioid Drug Withdrawal Treatment:
Clonidine (Catapres) (also used to treat hypertension therefore monitor closely for hypotension)
Opioid Drug Withdrawal Treatment:
Methadone (used during detox as part of the maintenance programme)
STIMULANTS
Drugs that are taken to decrease fatigue, increase alertness, elevate mood and make you feel happier
Stimulants can be used to treat narcolepsy (periods of acute sleepiness)
They block the feelings of depression
Can lead to physical and psychological dependence
(((Stimulants work by releasing norepinephrine (neurotransmitter)))
Cocaine
Cocaine is a white powder that comes from the leaves of the Coca plant
It is a strong stimulant with vasoconstriction effects
Methamphetamine
crystal meth IS THE MOST POTENT
Stronger CNS effects than other amphetamines
Powerful effects on the central nervous system which can lead to dependency within a few weeks
the release of large amounts of a dopamine
Other Amphetamines
methylenedioxyamphetamine
MDA, “love drug”
methylenedioxymethamphetamine
MDMA, “ecstasy” (common rave party drug)
Pill form (methylphenidate Ritalin, Dexedrine)
LSD (Lysergic acid diethylamide)
Stimulant Withdrawal:Signs and Symptoms
Peak period: 1 to 3 days Duration: 5 to 7 days Signs & Symptoms Social withdrawal Insomnia Depression, Suicidal thoughts and behavior, Paranoid delusions, hallucinations, delirium
In the acute phase treated with high doses of Benzodiazepines
DEPRESSANTS
Used to treat anxiety, irritability, tension, panic attacks, to control seizures and induce light short duration of anesthesia (for specific medical procedures)
TWO CLASSES OF DEPRESSANTS
Two main classes:
Benzodiazepines
Barbiturates
Benzodiazepines
Widely used for anxiety, panic disorders and insomnia
They are relatively safe but when combined with alcohol or other CNS depressants they can be fatal
Half life ranges from 1-100 hours
Benzodiazepines:Flunitrazepam (Rohypnol)
“Roofies”
“Date Rape Drug”.
When combined with alcohol causes amnesia
This is generally slipped into one’s drink and when consumed causes symptoms in 1 minute
The victim has no recall of any events.
Barbiturates
Cause more CNS and respiratory depression when compared to BZ
Rapidly penetrate into the brain to produce CNS depression and anesthesia
Their half life is very long.
Their abuse generally increases with those who do not get positive effects with BZ
They have a serious dependency effect on the body
SAFETY
BZ are more commonly prescribed by physicians as they have a wide safety margin
Barbiturates lead to more serious side effects with increased duration of effects
Enhanced symptoms when combined with alcohol
Death is usual due to respiratory depression or arrest
Depressant Withdrawal:Signs and Symptoms
Agitation; muscular weakness; diaphoresis; delirium; hallucinations, convulsions; anxiety, hypertension, tachycardia, hyperthermia and tremors.
Withdrawal occurs with abrupt discontinuation of BZ especially if the patient has been taking them for a long time (months to years)
Benzodiazepine ANITDOTE
Fumazenil (Anexate) is the direct antidote which may be used to reverse the acute sedative effects of benzodiazepines
Flumazenil antagonizes the action of BZ by directly competing at the receptor site in the CNS
Because Flumazenil has a higher affinity at the receptor, it knocks the BZ off, which allows it to bind to the receptor thereby reversing the sedative effect
ALCOHOL
AKA ethanol (ETOH) Causes CNS depression as well as respiratory depression with large consumption
Ethanol:Drug Effects
Causes CNS depression
Respiratory depression
Vasodilation, producing warm, flushed skin
Diuretic effect
Hypotension
Cardiac arrhythmias (high amounts)
It is rapidly absorbed producing peak effects in 30-60 minutes
Widely distributed in body water to all body organs
Metabolized in the liver
Inhibits ADH (antidiuretic hormone) thereby producing diuresis *****
Effects of Chronic Ethanol Ingestion
Nutritional and vitamin deficiencies (especially B vitamins)
Wernicke’s encephalopathy
Korsakoff’s psychosis
Polyneuritis
Seizures, mental disorders, confusion, stupor
Alcoholic hepatitis, progressing to cirrhosis
Can lead to fatalities
Ethanol Withdrawal
Hypertension Tachycardia Hyperthermia Cardiac arrhythmia Diaphoresis Tremors (severe withdrawal can lead to seizures) Agitation -irritability Confusion
Ethanol Withdrawal Treatment
Initial treatment with glucose Thiamine (prevents encephalopathy, seizures) Narcan (helps stimulate respiration) Diazepam (Valium) or Lorazepam (Ativan) Dosage and frequency depends on severity For severe withdrawal, monitoring in an intensive care unit is recommended Disulfiram (Antabuse) – selective use Counseling Individual Alcoholics Anonymous
NICOTINE
Releases epinephrine that creates physiologic stress rather than relaxation
Nicotine: Drug Effects
Increased heart rate and BP (due to cardiac stimulation)
Increased gastric activity (vomiting)
Rapidly absorbed by all routes
Highly metabolized and excreted in the urine
Nicotine Withdrawal
Manifested by cigarette craving
Irritability, restlessness, decreased heart rate and BP
Cardiac symptoms resolve in 3 to 4 weeks, but craving may persist for months or years
It is during this phase that people generally go back to smoking because of the intense cravings
Bupropion (Zyban) may be
prescribed to aid in smoking
cessation
stimulation of the SNS may result in
elevated values for vital signs and use of analgesics will depress vital signs because of CNS depressive effects.
acetaminophen poising
rapid weak pulse, dyspnea, cold and clammy
salicylate intox
^ HR , tinnitus, headache, nausea,
