Drugs for Pain Control

1
Drugs for Pain Control

• Chapter 12

2
Introduction

• Pain is an emotional experience characterized by
  unpleasant feelings, usually associate with
  trauma or disease.
• On a simple level, pain may be viewed as a
  defense mechanism that helps us to avoid
  potentially damaging situations and encourages us
  to seek medical help when necessary.

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Introduction

• The perception of pain and the psychological
  reaction to pain are highly individualized.

4
Pain Assessment

• Pain assessment is the first step to pain
  management
• Acute pain is a short-term sensation that is
  uncomfortable or hurtful.
• Chronic pain is when is is long-term.

5
Pain Assessment

• Two purposes of pain assessment.
• 1. Causemay be a symptom of an underlying
  disorder.
• 2. Selection of pharmacological agent to treat
  pain.

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Pain Assessment

• Non-pharmacological techniques to manage pain.
• Analgesics are classified as Non-narcotics or
  narcotics

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Nonpharmacological Techniques

• Pg. 194
• Accupuncture
• Massage
• Heat and cold packs
• Meditation
• Relaxation therapy
• Hypnosis
• Therapeutic touch.

8
Opioid Analgesics

• Analgesicsdrugs used for relief of pain
• Opioid analgesica natural or synthetic
  morphine-like substance responsible for reducing
  severe pain.
• Opioids are Narcotic substances, meaning that
  they produce numbness or stupor-like symptoms.

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Opioid Analgesics

• Several drugs are obtained from opium, a milky
  extract from the unripe seeds of the poppy plant.
• Opium consists of 9 to 14 morphine and 0.8 to
  2.5 codeine.

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Opioid Analgesics

• These natural substances are called opiates.

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Opioid Analgesics

• In a search for safer analgesics, chemists have
  created several dozen synthetic drugs with
  activity similar to that of the opiates.
• Opioid is a general term referring to any of
  these substances, natural or synthetic, and is
  often used interchangeably with the term opiate.

12
Opioid Analgesics

• Narcotic is a general term used to describe
  morphine-like drugs that produce analgesia and
  CNS depression.
• Narcotics may be natural, such as morphine, or
  synthetic such as meperidine (Demerol).

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Opioid Analgesics

• In common usage, a narcotic analgesic is the same
  as an opioid, and the terms are often used
  interchangeably.
• In drug enforcement, however, the term is often
  used for illegal drugs such as hallucinogens,
  heroin, amphetamines, and marijuana.

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Opioid Analgesics

• Opioids are drug of choice for moderate to severe
  pain that cannot be controlled with other classes
  of analgesics.

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Narcotic (Opioid) Analgesics

• Severe pain is controlled by Opioids.(Morphine)
• Classified by
• Chemical structure
• Mechanism of action
• efficacy
• Other effects other than analgesia
• Suppress cough reflex
• Slow GI motility
• Depress CNS
• Adverse effects
• Respiratory depression
• N/V

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Narcotic (Opioid) Analgesics

• Physical and psychological dependence
• DP Morphine pg. 199
• Antidote/opioid blockersDP naloxone (Narcan) pg.
  200.

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Opioids with mixed activity

• Effective at relieving pain, opioids have a
  greater risk for dependence than almost any other
  class of meds.
• Tolerance develops quickly to the euphoric
  effects, causing users to increase their doses
  and take the drug more frequently.

18
Opioids with mixed activity

• The higher and more frequent doses rapidly cause
  physical dependence in abusers.
• When attempt to d/c drug use, they experience
  extremely uncomfortable symptoms that lead many
  to continue their drug-taking behavior.

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Opioids with mixed activity

• As long as they continue the drug, they feel
  normal, and may continue work or social
  activities.
• If a person abruptly d/c the drug, they will
  experience withdrawal symptoms for about 7 days
  before overcoming the physical dependence.

20
Opioids with mixed activity

• The intense craving that characterizes
  psychological dependence may occur for many
  months, and even years, following d/c of opioids.
  

21
Opioids with mixed activity

• Methadone (Dolophine) is a common method to treat
  opioid dependence.
• Although it is an opioid, oral methadone does not
  cause the euphoria or the injectable opiods.

22
Opioids with mixed activity

• Methadone does not cure the dependence, and the
  pt must continue to take the drug to avoid
  withdrawal symptoms.
• This therapy, is called methadone maintenance,
  and may continue for many months or years.
• Methadone allows pts to return to productive
  work and social relationships without the
  physical, emotional, and criminal risks of
  illegal drug use.

23
NSAIDS

• 1. Non-narcotic (non-opioid) analgesics
• NSAIDsdrug of choice for mild to moderate pain.
• Aspirin
• Ibuprofen and
• ibuprofen-like drugs
• Selective COX-2 inhibitors

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NSAIDs

• NSAIDs are effective at treating moderate pain,
  inflammation and fever.
• Table 12.3 pg. 205.
• DP aspirin (acetylsalicyclic acid, ASA) pg. 204.

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Antipyretics

• Fever is a defense mechanism of the body that can
  be effectively treated with antipyretic
  medications.
• Antipyretics are drugs that reduce fever.

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Antipyretics

• Some antipyretics are also NSAIDs and, therefore,
  reduce pain and inflammation.
• Others may reduce fever and pain without
  affecting the inflammatory component.
• DP acetaminophen (Tylenol) pg. 207

27
Drugs for Migraine

• The goals of drug therapy for migraine headaches
  are to stop migraines in progress and to prevent
  them from reoccuring.
• Table 12.4 pg. 209.
• Tension HAs and Migraine HAs

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Drugs for Migraine

• Drugs that stop migraines
• Triptansfirst choice
• Ergotamine (Ergostat)oldest drug available
• Migranal
• Opiodswhen none of the above are effective.

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Drugs for Migraine

• Drugs that prevent onset--
• Beta adrenergic blockers
• Calcium channel blockers
• Antidepressants
• Anti-seizure drugs
• Only used if drugs that stop migraines not
  effective
• DPImetrex pg. 210