Pain drugs

Drugs Affecting the Central Nervous System

Nelia B. Perez RN, MSN

PCU - MJCN

Pain

Defined as an unpleasant sensory and emotional experience associated with either actual or potential tissue damage. Pain is what a client says it is. Pain exists whenever the patient says it does.

Acute Pain

Pain that is sudden in onset, usually subsides when treated, and typically occurs over less than 6-week period of time.

Chronic Pain

Persistent or recurring pain that is often difficult to treat. Typically lasts longer than 3 months.

Pain Threshold

Level of stimulus needed to produce a painful sensation.

Pain Tolerance

The amount of pain a client can endure without it interfering with normal function.

Pain Source

Somatic pain: originates from skeletal muscles, ligaments and joints.

Visceral pain: originates from organs and smooth muscle.

Superficial pain: originates from skin and mucous membranes.

Cultural Implications

Each culture has its own beliefs, thoughts, and ways of approaching, defining, and managing pain. Prayer Laying on of hands Healers

Implications for Transcultural Nursing Practice Assessment of the type of intervention the

person desires. Does the person wish traditional

interventions, expressions of nurturance and compassion, psychological support, physical interventions (soothing, having a brow wiped, relaxation)? cultural support? medication? Or a combination of these?

Cultural Groups and Pain

Stereotypes: Mexican Americans have a low pain tolerance. Italian Americans are very dramatic about their

pain Jewish Americans complain a lot about pain. African Americans report higher levels of chronic

pain and have a greater sensitivity to acute pain. Asian Americans do not express their pain.

Alternative Methods

Acupuncture Massage Herbs Heat or ice application Relaxation techniques Psychological counseling

Acupuncture

Nerve Pain Tincture

Recipe 1 tsp Saint Johns Wort (flowering top), skull cap

leaves, fresh oats & licorice root. ½ gtt each tincture

Ginger rhizome Vervain leaves

Nursing Responsibilities

Do a thorough assessment that includes questions about the patients cultural background and practices is important in the effective and individualized delivery of nursing care.

JCAHO Pain Standards

The Joint Commission's 2001 pain management standards state that every patient has a right to have his or her pain assessed and treated.

JCAHO standards dictate that a nurse will evaluate the patients response to the pain medication within 30 minutes to one hour after administration of the pain medication.

Pain Tools

Universal Pain Assessment Tool

Opioid Drugs

Originate from the opium poppy. 20 different alkaloids are obtained from the

unripe seed of the plant.

Opioid Analgesics

Powerful pain relievers. Classified according to their chemical

structure and action. Simple chemical modifications of the opium

alkaloids produce three different drugs. morphine-like drugs meperidine-like drugs methadone-like drugs

Anesthetic Drugs

Strong opioid analgesics used in combination with anesthetics during surgery. fentanyl sufentanil alfentanil

Goal: not only to relieve pain but also to maintain a balanced state of anesthesia.

General Anesthesia

Loss of sensation and usually of consciousness without loss of vital functions artificially produced by the administration of one or more agents that block the passage of pain impulses along nerve pathways to the brain

Local Anesthesia

Loss of sensation in a limited and usually superficial area especially from the effect of a local anesthetic.

Fentanyl

Fentanyl injection has a rapid onset and short duration.

Transdermal fentanyl patch is used for long-term pain management.

Opioids

Opioids used to control moderate to severe pain.

Schedule II Drugs

Classification – Opioid analgesics Morphine Codeine – often used in combination with

acetaminophen – Tylenol with codeine Hydrocodone – Vicodin - used in combination with

acetaminophen / aspirin / ibuprofen Hydromorphine – Dilaudid - More potent than

morphine Meperidine – Demerol Oxycodone – Percocet (with acetaminophen) or

Percodan (with aspirin)

Opioid Adverse Effects

Cardiovascular: hypotension, palpitations, flushing Central nervous system: sedation, disorientation,

euphoria, light-headedness, tremors. Gastrointestinal: nausea, vomiting, constipation Genitourinary: urinary retention Respiratory: Respiratory depression and

aggravation of asthma.

Contraindications

Known drug allergy Severe asthma Used with caution in:

Patients with severe head injuries (mask level of consciousness or LOC)

Morbid obesity with sleep apnea (depress respirations while asleep)

Paralytic ileus (bowel paralysis) – opioids tend to slow bowel

Psychologic Dependence

Addiction: characterized by behaviors that include one or more of the following: Impaired control over drug use Compulsive use Continued use despite harm Craving

Physical Dependency

Physiological adaption Results in withdrawal symptoms when the

drug is discontinued. Withdrawal symptoms include:

Mental agitation Tachycardia Elevated blood pressure Seizures

Opioid Tolerance

State of adaption which results in reduced effects of drug resulting on use of higher dosing to get desired effect.

Toxicity

Opioid antagonist bind to occupy all the receptor sites blocking the action of the opiod drug. nalaxone naltrexone

Naloxone

Brand name: Narcan Classification Pharmacologic: opioid antagonist Classification Therapeutic: antidote for opioid Action: Competitively blocks the effects of opioids,

including CNS and respiratory depression, without producing any agonist (opioid-like) effects.

Therapeutic Effects: reversal of signs of opioid excess.

Narcan

Route IV onset in 2-3 minutes peak unknown duration 45 minutes

IM, Subq onset 2-5 minutes peak unknown duration > 45 minutes

Drug Calculation

The IV dose for naloxone (Narcan) is 0.02 to 0.2 mg q 2-3 minutes until response is obtained.

Physician orders 0.1 mg The drug is provided as 0.4 mg / mL How much would you draw up to give the

appropriate dose? ____________

Morphine Sulfate

Classification Pharmacologic: Opioid agonist Classification Therapeutic: opioid analgesic Indications: severe pain (postoperative,

fractures, burns), pulmonary edema, and pain associated with myocardial infarct (MI).

Morphine

Action: Binds to opiate receptors in the CNS. Alters the perception of and response to painful stimuli while producing generalized CNS depression Therapeutic Effects: decrease in severity of pain

Adverse Reactions: severe respiratory depression, constipation

Morphine Effects

IV maximal analgesia and respiratory depression would occur within 10 to 20 minutes

IM: within 30 minutes Sub Q: 60 to 90 minutes PO: peak activity occurs in about 60 minutes

* higher dosage needed due to metabolism of drug in the liver

Morphine Dosing

Tablets come in 15 mg or 30 mg Solution for IM, IV or sub Q: 10 mg/ml most

common

Medication Calculation

Physician order 6 mg of morphine sulfate q 3-4 hours prn for severe pain.

The drug is provided as 10 mg / 1 mL. How much of the drug would you need to

draw up the give the appropriate dose?

Nursing Responsibilities

Pain assessment Base-line vitals Re-assess vitals after pain med administered Assess bowel function Overdose: Narcan used to reverse

respiratory depression Constipation: ambulate! dietary fiber, fluids,

stool softener

Meperidine

Therapeutic classification: opioid analgesic Pharmacologic classification: opioid agonist Schedule II drug Action: Binds to opiate receptors in the CNS.

Alters the perception of and response to painful stimuli, while producing generalized CNS depression

Therapeutic effects: Decrease in severity of pain.

Meperidine

Demerol is a synthetic drug with the same uses and adverse effects as morphine.

Less nausea and vomiting. Use with caution due to neurotoxic

metabolism with chronic use CNS agitation (often exhibited as confusion) Hallucinations Tremors seizures

Meperidine Dosing

IV or IM Provided as 10 mg/mL, 50 mg /mL, 75

mg/mL or 100 mg/mL Dosage for adults: 50 to 150 mg every 3-4

hours Dosage for pediatrics: 1 to 1.8 mg / kg q 3-4

hours (not to exceed 100 mg dose)

Medication calculation

The physician order meperidine 75 mg prn q 3-4 hours for pain.

The vial provided is 50 mg / 1 mL. How much of the mediation would you need

to draw up to give the appropriate dose?

Codeine

Classification Pharmacologic: opioid agonist Classification Therapeutic: allergy, cold and

cough remedies, antitussives, opioid analgesics

Schedule II drug

Codeine

Action: Binds to opiate receptors in the CNS. Alters the perception of and response to painful stimuli while producing generalized CNS depression – decreases cough reflex – decreases GI motility

Codeine

Side Effects: confusion, sedation, hypotension, constipation

Nursing responsibilities - same as morphine Evaluation of effectiveness:

Decrease in severity of pain without significant alteration in level of consciousness

Suppression of cough Control of diarrhea

Codeine Dosing

Usually supplied in combination with other analgesics Tylenol with codeine

Tylenol # 2 = 15 mg codeine + 300 mg Tylenol Tylenol # 3 = 30 mg codeine + 300 mg Tylenol Tylenol # 4 = 60 mg codeine + 300 mg Tylenol

Most often given po with food Most common side-effect: constipation

Methadone

The drug of choice for detoxification treatment for opioid addiction.

Nonopioid Analgesics

Acetaminophen: Tylenol Salicylates: aspirin

Acetaminophen

Action: blocks peripheral pain impulses by inhibition of prostaglandin synthesis.

Indication: treatment of mild to moderate pain.

Contraindications: Drug allergy Severe liver disease G6PD disease

Toxicity

Ingestion of large amounts of acetaminophen, as in acute overdose, or even chronic unintentional misuse can cause hepatic necrosis.

Acute ingestion of acetaminophen doses of 150 mg / kg or more may result in hepatic toxicity.

Treatment

Acetylcysteine or Mucomyst Action: Works by preventing the hepatotoxic

metabolites of acetaminophen from forming. Initial loading dose of 140 mg / kg orally. Followed by 70 mg / kg every 4 hours for 17

additional doses. Note: if patient vomits within 1 hour the dose

should be given immediately. All 17 doses must be given.

Drug Calculation

A teenage girl is admitted for Tylenol overdose weight is 120 pounds.

Mucomyst is ordered at 140 mg / kg for the lst dose.

Weight in kg ______ What dose would you give __________ in

mg? What dose would you give ________ in

grams?

Anti-inflammatories

Chapter 44

Inflammation

Localized protective response stimulated by injury to tissues that serves to destroy, dilute, or wall off both the injurious agent and the injured tissue.

Inflammatory response

Mediated by two pathways: Prostaglandin (PG) Leukotriene (TL)

Nonsteroidal anti-inflammatories Most commonly prescribed drugs. 70 million prescriptions per year 23 different NSAIDS

How do they work?

Anti-inflammatories worth by inhibiting the leukotriene (LT) and prostaglandin (PG) pathways.

Most NSAIDS act on one or both of the pathways.

Two important enzymes: Cox 1 and Cox 2 (they have a role in maintaining gastrointestinal mucosa.

Side Effects of NSAIDs

One of the more common complaints is gastrointestinal distress Heart burn Gastrointestinal bleeding

NSAIDs

Used to treat rheumatoid arthritis and osteoarthritis.

Rheumatoid Arthritis

Systemic inflammatory disease often effecting multiple joints. Involves inflammation of the tissue surrounding the joints that can lead to destruction of the joint.

Symptoms include pain, stiffness and reduced range of motion.

Goal of drug therapy is to reduce the symptoms – no cure

Rheumatoid Arthritis

Drugs used in arthritis

Drugs: Aspirin (has been placed by newer drugs due to

gastrointestinal bleeding) NSAIDs DMARDs (Disease-modifying antirheumatic

drugs)

Acetic Acid Drugs

Most widely knows: Aspirin Aspirin (acetylsalicylic acid) was the first of

this drug classification (1899). Other acetic drugs:

indomethacin (Indocin) diclofenac (Voltaren, Cataflam)

Reyes Syndrome The acetic classification of drugs (Aspirin) is

contraindicated in children. Reyes syndrome is a neurological disease

process thought to be trigger by the use of aspirin in children (flu and chickenpox).

Fever in children should always be managed with acetaminophen (Tylenol).

naproxen

Trade name: Naprosyn, Aleve Therapeutic classification: nonopioid

analgesic, NSAIDs Action: inhibits prostaglandin synthesis. Indications: dysmenorrhea, inflammatory

disorders including rheumatoid arthritis Therapeutic effects: decrease pain,

suppression of inflammation.

Antirheumatic Drugs

Disease-modifying antirheumatic drugs Drugs have a slow onset of action often

taking up to several weeks to see results. A whole new group of IV meds have been

developed to control symptoms in patients with multiple joint involvement.

Gout

When the body has to much uric acid, deposits of uric acid crystals collect in tissue and joints

allopurinol

Trade name: Lopurin, Aloprim Action: inhibits the production of uric acid. Client teaching:

Advise patient to take with large glass of water. Alcohol may decrease effectiveness of the drug