Drugs for Pain Control Chapter 12
Introduction ď‚— Pain is an emotional experience
characterized by unpleasant feelings, usually associate with trauma or disease. ď‚— 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.
Introduction ď‚—The perception of pain
and the psychological reaction to pain are highly individualized.
Pain Assessment Pain assessment is the
first step to pain management Acute pain is a shortterm sensation that is uncomfortable or hurtful. Chronic pain is when is is long-term.
Pain Assessment Two purposes of pain
assessment. 1. Cause—may be a symptom of an underlying disorder. 2. Selection of pharmacological agent to treat pain.
Pain Assessment ď‚—Non-pharmacological
techniques to manage pain. ď‚—Analgesics are classified as Nonnarcotics or narcotics
Nonpharmacological Techniques Pg. 194 Accupuncture Massage Heat and cold packs Meditation Relaxation therapy Hypnosis Therapeutic touch…….
Opioid Analgesics Analgesics—drugs used
for relief of pain Opioid analgesic—a natural or synthetic morphine-like substance responsible for reducing severe pain. Opioids are Narcotic substances, meaning that they produce numbness or stupor-like symptoms.
Opioid Analgesics ď‚—Several drugs are
obtained from opium, a milky extract from the unripe seeds of the poppy plant. ď‚—Opium consists of 9% to 14% morphine and 0.8% to 2.5 % codeine.
Opioid Analgesics ď‚—These natural
substances are called opiates.
Opioid Analgesics ď‚— In a search for safer
analgesics, chemists have created several dozen synthetic drugs with activity similar to that of the opiates. ď‚— Opioid is a general term referring to any of these substances, natural or synthetic, and is often used interchangeably with the term opiate.
Opioid Analgesics ď‚—Narcotic is a general
term used to describe morphine-like drugs that produce analgesia and CNS depression. ď‚—Narcotics may be natural, such as morphine, or synthetic such as meperidine (Demerol).
Opioid Analgesics ď‚— In common usage, a narcotic
analgesic is the same as an opioid, and the terms are often used interchangeably. ď‚— In drug enforcement, however, the term is often used for illegal drugs such as hallucinogens, heroin, amphetamines, and marijuana.
Opioid Analgesics ď‚—Opioids are drug of
choice for moderate to severe pain that cannot be controlled with other classes of analgesics.
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
Narcotic (Opioid) Analgesics Physical and
psychological dependence DP Morphine pg. 199 Antidote/opioid blockers—DP naloxone (Narcan) pg. 200.
Opioids with mixed activity Effective at relieving pain,
opioids have a greater risk for dependence than almost any other class of med’s. Tolerance develops quickly to the euphoric effects, causing users to increase their doses and take the drug more frequently.
Opioids with mixed activity ď‚— The higher and more
frequent doses rapidly cause physical dependence in abusers. ď‚— When attempt to d/c drug use, they experience extremely uncomfortable symptoms that lead many to continue their drug-taking behavior.
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.
Opioids with mixed activity ď‚—The intense craving
that characterizes psychological dependence may occur for many months, and even years, following d/c of opioids.
Opioids with mixed activity ď‚—Methadone
(Dolophine) is a common method to treat opioid dependence. ď‚—Although it is an opioid, oral methadone does not cause the euphoria or the injectable opiods.
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 pt’s to return to productive work and social relationships without the physical, emotional, and criminal risks of illegal drug use.
NSAIDS 1. Non-narcotic (non-opioid)
analgesics NSAIDs—drug of choice for mild to moderate pain. Aspirin Ibuprofen and ibuprofen-like drugs Selective COX-2 inhibitors
NSAID’s NSAIDs are effective at
treating moderate pain, inflammation and fever. Table 12.3 pg. 205. DP aspirin (acetylsalicyclic acid, ASA) pg. 204.
Antipyretics ď‚—Fever is a defense
mechanism of the body that can be effectively treated with antipyretic medications. ď‚—Antipyretics are drugs that reduce fever.
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
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 HA’s and Migraine HA’s
Drugs for Migraine Drugs that stop migraines Triptans—first choice Ergotamine (Ergostat)—
oldest drug available Migranal Opiods—when none of the above are effective.
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 DP—Imetrex pg. 210