PHARMACOLOGY
MIDTERM EXAM REVIEW
2025
Opioid analgesics – used to manage moderate to severe pain
o Pain relievers that contain opium, derived from the opium poppy or chemically related to opium
o Narcotics: very strong pain relievers
o Opioid and narcotics are used interchangeably.
o Indicated for:
Opioids also suppress the medullary cough center, which results in cough suppression.
Treatment of diarrhea (Lomotil)
Balanced anesthesia
Opioid/acetaminophen – combination products
Percocet
Vicodin
Vicodin ES
Vicodin HP
Tylenol w/Codeine
Do not exceed 3-4mg per day
o Potential Opioid adverse effects
constipation – stool becomes excessively dehydrated because it remains in the GI tract longer.
Nausea & vomiting are often experienced.
Respiratory depress is associated with excessive sedation and long-term use is generally associated as well.
Dry mouth, urinary retention, pruritus (treated with Benadryl), dysphoria, euphoria, sleep disturbances, or
sexual dysfunction may occur but are less common
o Opioid induced adverse effects
Hypotension, flushing, bradycardia – cardiovascular
Sedation, disorientation, euphoria, lightheadedness, dysphoria – central nervous
Nausea, vomiting, constipation, biliary tract spasm – GI
Urinary retention – GU
Itching, rash, wheal formation – integumentary
Respiratory depression (often seen more in patients with preexisting condition such as asthma, COPD, or sleep
apnea) and possible aggravation of asthma –respiratory
o Contraindications
Known drug allergy and severe asthma.
Extreme caution is to be used in cases of respiratory insufficiency, especially when resuscitative equipment is not
available and in conditions involving elevated intracranial pressure, morbid obesity, and/or sleep apnea,
myasthenia gravis, paralytic ileus, pregnancy, especially with long-term use or high dosages.
o Toxicity and management of overdose
Naloxone is used in the management of opioid overdose. Also used for alcohol and opioid addiction, in small doses
it can treat itching associated with opioid use as well.
o Interactions
, Co-administration of opioids with alcohol, antihistamines, barbiturates, benzos, phenothiazine, and other CNS
depressants can result in additive respiratory depressant effects.
o Lab tests
Opioids can cause an abnormal increase in the serum levels of
Amylase
Alanine aminotransferase
Alkaline phosphatase
Bilirubin
Lipase
Creatinine kinase
Lactate dehydrogenase
Creatinine
Other abnormal results include
A decrease in urinary ketosteroid levels
An increase in urinary alkaloid & glucose concentrations
LFTs
PT
PTT
Bilirubin
Albumin
o Lifespan considerations
Pediatric population
Elderly
Cultural
Gender differences
o Opiate withdrawal
Narcotic withdrawal opioid abstinence syndrome
Manifested as:
--Anxiety, irritability, chills and hot flashes, joint pain, lacrimation, rhinorrhea, diaphoresis, nausea, vomiting,
abdominal cramps and diarrhea
--Related nursing care
Agonist – to alleviate severe pain
o Bind to opioid receptor in the brain, causing an analgesic response (reduction in pain sensation)
o Hydromorphone (Dilaudid): seven times more potent than morphine
Propoxyphene hydrochloride ....?
Transdermal Fentanyl Patches
- Patients ONLY who are considered opioid tolerant may use it. That is, those in severe pain requiring daily round-
the-clock treatment with alternative treatments being inadequate in pain control.
- All other extended-release opioids must be discontinued or tapered prior to the initiation of transdermal fentanyl
therapy, and, because it is to be used only in opioid-tolerant patients, it is not indicated to be begun as the first
opioid of use.
- Inform patients that heat, such as in the form of heating pad/pack, must NEVER be applied over a patch. This
increases circulation from the application of heat and may result in increased absorption of the medication, causing
an overdose.
- The patch is customarily applied externally for 72 hours and then replaced with a new patch. Removing the old
before applying new one.
- Highly effective in the treatment of various chronic pain syndromes such as cancer-induced pain.
- Patches take about 6-12 hours to reach steady-state pain control after the first patch is applied.
- When removed, it takes about 27 hours for the amount of fentanyl to reduce by 50%.
, - Other hazards are cutting the patch which can also increase the diffusion of the drug into the body.
- Unused patches should be flushed down the toilet.
Fentanyl
- Used to treat moderate to severe pain.
- Available in
o parenteral injections – most used in perioperative settings and in ICU for sedation during mechanical ventilation.
o Patches
o Buccal lozenges
o And buccal lozenges on a stick
Hydromorphone (Dilaudid)
- Very potent opioid.
- Approx. 7 times more potent than morphine.
- 1 mg of IV or IM hydromorphone is equivalent to 7mg of morphine!
- Exalgo is the extended release oral delivery which is difficult to crush or extract for injection.
Meperidine hydrochloride (Demerol)
- Must be used with caution, if at all, in older adult patients an in patients who require long-term analgesia or who
have kidney dysfunction.
- Can accumulate to toxic levels and lead to seizures.
- Not recommended for long-term pain treatment use.
- Still used in emergency department settings for acute migraine headaches and in the immediate postoperative
period to reduce shivering.
- Available in oral and inj. Forms.
- High risk for toxicity
Methadone hydrochloride (Dolophine)
- Opioid of choice for the detoxification treatment of opioid addicts in methadone maintenance programs.
- Absorbed in the GI tract.
- Eliminated through the liver, which makes it a safer choice than some other opioids for patients with renal
impairment.
- May cause cardia dysrhythmias.
- Available in oral and inj. Forms.
Morphine sulfate (Morphine)
- Indicated for severe pain and has a high abuse potential.
- Available in oral, inj., and rectal dosage forms. As well as epidural and PCA cartridges.
- Morphine contain a potentially toxic metabolite known as “morphine-6-glucuronide” which in
accumulation is more likely to occur in patients with renal impairment.
Oxycodone hydrochloride
- Related to morphine.
- Commonly combined with acetaminophen (Percocet) and with aspirin (Percodan).
- Available in immediate-release formulations (OxyIR) and sustained-released formulations (OxyContin).
Partial agonist
- Binds to a pain receptor and causes a weak pain response than does a full agonist
- Used in situations requiring short-term pain control, such as after obstetric procedures (post-operative).
- These drugs are usually not strong enough to for management of longer-term chronic pain (e.g.cancer pain, chronic
lower back pain).
- Adverse reactions are similar to opioids but with a lower incidence of respiratory depression.
- Do not give with opioid agonist because it may cause withdrawal or less analgesic effect.
- Monitor respirations and V/S, constipation, and CNS depression.
- Labs: liver & kidney
- Common drugs
, o Butorphanol (Stadol)
o Nalbuphine (Nubain)
o Pentazocine (Talwin)
Antagonists
- Binds to a pain receptor but does not reduce pain signal. Reverses the effects of an agonist & partial agonist.
Naloxone hydrochloride (Narcan) – used for opioid overdose.
- Works as a blocking drug for the opioid drugs.
- The drug does not produce analgesia or respiratory depression.
- The drug of choice for the complete or partial reversal of opioid-induced respiratory depression.
- Also indicated in cases of suspected acute opioid overdose.
- The primary adverse effect is opioid withdrawal syndrome, which can occur with abrupt over- reversal in opioid
tolerant patients.
- Adverse effects
o Raised or lowered BP
o Dysrhythmias
o Pulmonary edema
o Withdrawal
- Available only in injectable forms.
- Available without a prescription.
- Contraindicated in patients with a history of hypersensitivity to it.
Nonopioid Analgesics & misc.
- Acetaminophen is the most widely used.
- All drugs in the NSAID class (aspirin, ibuprofen, naproxen, Celebrex, and others) are nonopioid analgesics.
- Used for management of pain, especially associated with inflammatory conditions such as arthritis.
- Tramadol and transdermal lidocaine are misc.
- Mechanism of action
o It blocks peripheral pain impulses by inhibition of prostaglandin synthesis. Also lowers febrile body temperatures.
o In contrast to NSAIDs, acetaminophen lacks anti-inflammatory effects.
o Acetaminophen products are not usually associated with cardiovascular effects (e.g.edema) or platelet effects
(e.g. bleeding), as are aspirin and other NSAIDs. It also does not cause aspirin-related GI tract irritation or
bleeding, nor any of the aspirin-related acid-base changes.
- Indications
o Acetaminophen is indicated for the treatment of mild to moderate pain and fever.
o Appropriate substitute for aspirin. For patients who cannot tolerate.
o It is also anti-fever drug of choice in children and adolescents with flu syndromes. Aspirin in these age groups is
associated with Reye’s syndrome.
- Contraindications
o Known drug allergy, severe liver disease, and the genetic disease G6PD deficiency.
- Adverse effects
o Possible – Skin disorders & N/V
o Less common but more severe are of blood disorders or dyscrasias (e.g. anemias) and nephrotoxicity’s, and
hepatotoxicity (the most serious adverse effect of acetaminophen) – associated with excessive doses.
o FDA limits daily doses to 4000mg daily
o Tylenol manufactures limit to 3000mg/day
o Patients with liver disease or chronic alcohol consumption are advised not to exceed 2000mg/day
- Toxicity and management of overdose
o May cause hepatic necrosis
o Long-term ingestion of large doses also causes nephropathy.