CENTRAL NERVOUS SYSTEM DRUGS Pt 2

What are the nursing implications for patients receiving general anesthesia?

Nursing management is primarily focused on preoperative and postoperative care.

What should be included in preoperative counseling for patients receiving general anesthesia?

Counseling should address anxiety, medication history, and respiratory and cardiovascular function.

What should patients be informed about regarding their experience after coming out of anesthesia?

Patients should be informed about how they will feel, the need to take deep breaths, and that they might have to urinate.

What ongoing assessments are necessary for postoperative patients who received general anesthesia?

Ongoing assessment of cardiovascular and respiratory systems, CNS function (level of consciousness), GI, and urinary tract function.

What are the three categories of central nervous system drugs mentioned?

Opioid Analgesics, Opioid Antagonists, and Non-opioid Centrally Acting Analgesics

What is the definition of analgesics?

Drugs that relieve pain without causing loss of consciousness.

Which type of analgesics are considered the most effective pain relievers?

Opioid analgesics

Name four widely used agents in the opioid family.

Morphine, fentanyl, codeine, and oxycodone (Oxycontin)

What is a narcotic?

A narcotic is any drug, natural or synthetic, that has actions similar to those of morphine.

What is an opiate?

An opiate is a term applied only to compounds present in opium, such as morphine and codeine.

What are the three main classes of opioid receptors?

The three main classes of opioid receptors are mu, kappa, and delta.

Which opioid receptor is most important for analgesic effects?

Mu receptors are the most important because opioid analgesics act primarily by activating them.

What are the responses to activation of mu receptors?

Responses include analgesia, respiratory depression, euphoria, and sedation.

What effects can activation of kappa receptors produce?

Activation of kappa receptors can produce analgesia and sedation.

How are drugs that act at opioid receptors classified?

They are classified based on how they affect receptor function.

What are pure opioid agonists?

Pure opioid agonists are drugs that activate mu receptors to produce pain relief.

What are agonist-antagonist opioids?

Agonist-antagonist opioids provide pain relief but do not produce other opioid symptoms.

What are pure opioid antagonists?

Pure opioid antagonists are drugs that block the effects of opioids.

What are pure opioid agonists?

They activate mu receptors and kappa receptors, producing analgesia, euphoria, sedation, respiratory depression, physical dependence, and constipation.

What should you do before giving morphine?

Ask the patient's pain level and obtain a set of vitals.

What should you do after administering morphine if the vitals are bad?

Sit the patient up, give oxygen, and administer Narcan.

What is the strongest opioid agonist?

Morphine.

What is an example of a moderate to strong opioid agonist?

Codeine.

What are agonist-antagonist opioids?

They are opioids that can produce analgesia when administered alone and include Pentazocine, Nalbuphine, Butorphanol, and Buprenorphine.

What is the prototype of agonist-antagonist opioids?

Pentazocine (Talwin).

What do pure opioid antagonists do?

They act as antagonists at mu and kappa receptors, primarily reversing respiratory and CNS depression caused by opioid agonist overdose.

What is the prototype of pure opioid antagonists?

Naloxone (Narcan).

What happens if naloxone is administered in excessive dosage to someone physically dependent on opioid agonists?

It will precipitate an immediate withdrawal reaction.

What is the prototype of strong opioid analgesics?

Morphine

What are the principal indications for morphine?

Relief of moderate to severe pain

What is the mechanism of analgesic action of morphine?

Relieves pain by mimicking the action of endogenous opioid peptides, primarily at mu receptors

What are some pharmacologic effects of morphine?

Analgesia, sedation, euphoria, respiratory depression, cough suppression, and suppression of bowel motility

What is a major adverse effect of morphine that is important to monitor?

Respiratory depression

What are some common adverse effects of morphine?

Constipation, orthostatic hypotension, urinary retention, cough suppression

What is a specific adverse effect of morphine related to the biliary system?

Biliary colic (spasms of the common bile duct)

Which opioid can be used instead of morphine to cause less smooth muscle spasm?

Meperidine (Demerol)

What are some neurological adverse effects of opioids?

Delirium and agitation

What is the risk of using opioids before conception or during early pregnancy?

Increased risk of serious birth defects, including congenital heart defects

What effect do opioids have on pupils?

Opioids constrict pupils (miosis)

What should never be given to a child?

Demerol (meperidine)

What must morphine cross to enter the central nervous system (CNS)?

The blood-brain barrier (BBB)

What is the lipid solubility of morphine?

Poor

What fraction of the morphine dose reaches sites of analgesic action?

Only a small fraction

How is morphine inactivated?

By hepatic metabolism

What happens to morphine when taken by mouth?

It must pass through the liver

What occurs to most of the morphine during the first pass through the liver?

It is inactivated

What is tolerance in the context of drug use?

Tolerance is a state in which a larger dose is required to produce the same response that could formerly be produced with a smaller dose.

What can continuous use of morphine cause?

Continuous use of morphine can cause tolerance and physical dependence.

To which effects does tolerance develop when using morphine?

Tolerance develops to analgesia, euphoria, and sedation.

What is cross tolerance?

Cross tolerance exists among the opioid agonists.

What is physical dependence?

Physical dependence is a state in which an abstinence syndrome will occur if drug use is abruptly stopped.

What causes opioid dependence?

Opioid dependence results from adaptive cellular changes that occur in response to the continuous presence of these drugs.

Is physical dependence a problem when opioids are taken acutely to treat pain?

No, it is not a problem when opioids are taken acutely to treat pain, such as postoperative pain.

How should opioids be administered for postoperative pain management?

Opioids should not be given on a PRN basis but rather through PCA or around the clock for the first 24-48 hours after surgery.

Can patients experience breakthrough pain while on continuous opioid medication?

Yes, patients can still experience breakthrough pain while continuously taking pain medications.

Is there a chance for drug addiction when using opioids for short-term postoperative pain?

No, there is no chance for drug addiction when using opioids for short-term use like postoperative pain.

What can CNS depressants do when taken with morphine?

They can intensify sedation and respiratory depression.

What effect do anticholinergic drugs have when taken with morphine?

They can exacerbate morphine-induced constipation and urinary retention.

What is a potential interaction between hypotensive drugs and morphine?

They can exacerbate morphine-induced hypotension.

What syndrome can occur from combining morphine with Monoamine Oxidase Inhibitors?

It can produce a syndrome characterized by excitation, delirium, hyperpyrexia, convulsions, and severe respiratory depression.

What is Fentanyl?

A strong opioid analgesic with high milligram potency, given in micrograms, and can be administered IM, IV, transdermal, or transmucosal.

What are Alfentanil and Sufentanil?

IV opioids related to fentanyl, used for induction of anesthesia.

What is Remifentanil?

An IV opioid with rapid onset and brief duration.

What is Meperidine?

An opioid that shares major pharmacologic properties with morphine, has a short half-life, and can adversely interact with several drugs.

What are the pharmacologic properties of Methadone?

Similar to morphine, effective orally, has a long duration of action, and can accumulate with repeated dosing.

What is Methadone used for?

To treat pain and opioid addiction, although its use for pain control has declined.

What effect does Methadone have on the QT interval?

It prolongs the QT interval and may produce lethal arrhythmias.

What is Levaquin?

An antibiotic that prolongs the QT interval and may produce lethal arrhythmias.

What is Codeine used for?

Relief of mild to moderate pain and as an effective cough suppressant.

How is Codeine usually administered?

By mouth.

What are the side effects of Codeine?

Dose limiting.

Can Codeine be combined with other analgesics?

Yes, it can be combined with nonopioid analgesics like acetaminophen or aspirin.

What is Oxycodone used for?

Relief of moderate to severe pain.

What are the brand names for Oxycodone?

Oxycontin, Roxicodone, OxyIR.

How is Oxycodone administered?

Orally.

What is a unique feature of Oxycodone formulations?

It can come in extended-release forms.

Who is typically prescribed Oxycodone?

Patients with cancer or those needing relief for breakthrough pain.

What is Hydrocodone used for?

Relief of pain and suppression of cough.

What are some brand names for Hydrocodone combination products?

Vicodin, Vicoprofen, and Loratab.

What is Tapentadol used for?

Oral therapy for moderate to severe pain, acute or chronic.

What is the minimum age for patients to use Tapentadol?

18 years and older.