Chapter 12Drugs for Pain Control

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.

Introduction 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 short-term 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 Non-

pharmacological techniques to manage pain.

Analgesics are classified as Non-narcotics or narcotics

Nonpharmacological TechniquesPg. 194AccupunctureMassageHeat and cold packsMeditationRelaxation therapyHypnosisTherapeutic

touch…….

Opioid Analgesics Analgesics—drugs used

for relief of painOpioid 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 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.

Opioid Analgesics These natural

substances are called opiates.

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.

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).

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.

Opioid Analgesics 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 structureMechanism of actionefficacy

Other effects other than analgesiaSuppress cough reflexSlow GI motilityDepress CNS

Adverse effects Respiratory depressionN/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 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.

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 The intense

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

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.

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’sNSAIDs are effective

at treating moderate pain, inflammation and fever.

Table 12.3 pg. 205.DP aspirin

(acetylsalicyclic acid, ASA) pg. 204.

Antipyretics Fever is a defense

mechanism of the body that can be effectively treated with antipyretic medications.

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

migrainesTriptans—first choiceErgotamine (Ergostat)

—oldest drug availableMigranalOpiods—when none of

the above are effective.

Drugs for Migraine Drugs that prevent

onset--Beta adrenergic

blockersCalcium channel

blockersAntidepressantsAnti-seizure drugsOnly used if drugs that

stop migraines not effective

DP—Imetrex pg. 210