Chapter 3 MRIS 210

pharmacology

study of drugs, their actions, dosage, therapeutic uses (indications), and adverse effects

drug

substance that alters biologic activity in a person

drug can be natural

plants, animals, microorganisms

drug can be synthesized

manufactured drug come from plant or animal active ingredient is isolated and refined in a
lab and mass produced as synthesized chemical

drug prescribe for what reasons

Promote healing
– Anti-inflammatory
Cure disease
– Antibacterial
Control or slow progress of a disease
– Cancer chemotherapy
Prevent disease
– Vaccine

Alter neurotransmission
– Antidepressants
Decrease risk of complications
– Anticoagulants
Increase function and comfort
– Analgesics for pain
Provide replacement therapy
– Insulin
Reduce excessive activity in the body
– Proton pump inhibitors (sedative or
anti-anxiety drug

Pharmacodynamics

drug-induced responses of physiologic systems

Pharmacokinetics

Drug amounts at different sites after administration

Pharmacotherapeutics

Choice and drug application for disease prevention, treatment, or diagnosis

Toxicology.

body’s response to drugs, harmful effects, symptoms, tx and identification

Pharmacy –

prep, compounding, dispensing, and recordkeeping of therapeutic drugs

Therapeutic (desired) action may be:

Stimulating or inhibiting cell function

blocking biochemical actions in tissues

Classification

Grouped by their primary pharmacologic action and effect

Indications

Approved for uses to treat conditions for which the drug has been proved to be effective

Contraindications

Circumstances under which a drug
should not be administered

Side effects

Mild, undesirable effects of a drug,
even at recommended dose (dry
mouth, drowsiness)

Adverse or toxic effects

Drug effects that are dangerous, cause significant tissue damage, or are life-threatening (excessive bleeding). Discontinue drug or reduce dosage

Hypersensitivity―

allergic reactions
– Reactions may be mild (rash) or can
result in anaphylaxis (shock,
decreased BP, airways narrow). Stop
med

Idiosyncratic reactions

Unusual and unexpected responses
to a drug (excessive excitement after
sedative)

Iatrogenic

Negative effect associated with
administration of drug caused by med
error, drug overdose, or unusual
response

Teratogenic

Harmful effect on fetus, developmental defects

Interactions:

drug effect modified by combination with another drug (med
plus alcohol)

Synergism

Effect of drug combination may be
greater than the sum of the effects of
the individual drugs (lead to coma or
hemorrhage). Reduce dose of each
to get desired results with less side
effects

Antagonism

Combination greatly decreases the
effect of each drug. Would be
hazardous in patient with heart
disease or serious infection.

Potentiation

One drug enhances the effect of a
second drug. Include epinephrine
with local anesthetic to prolong effect
of anesthetic without increasing the
dose

Dose

refers to the amount of a drug given at a single time,

Dosage

total amount of the drug given over a period of time

child dosing

best calculated by child’s weight, not
age

Loading dose

Larger dose may be administered
initially to raise blood levels to an
effective level

Frequency of dosing

Important to maintain effective blood
levels of the drug without reaching
toxic levels

Optimum dosing schedule

Established for each drug based on
• Absorption, transport in the blood,
half-life of the drug

Timing

– Directions regarding
• Timing related to meals
• Daily events (at bedtime, before
meals)
• Sleep (1/2 hr before bedtime

Factors Influencing Blood Levels of a Drug

Liver and kidney function
– Absorption and excretion
• Circulation and cardiovascular function
• Age – modified for children and elderly
• Body weight and proportion of fatty tissue
• Activity level, exercise
• Food and fluid intake
• Genetic factors
• Health status, presence of other diseases, chronic or acute

Local adminsitration

includes topical application to the skin, application to the mucous membranes, oral administration, inhalation for selected respiratory conditions, and iontophoretic administration for local inflammation.

systemic administraion

transdermal, oral, sublingual, transdermal, rectal (suppository), inhalation, subcutaneous or intramuscular injection, intravenous injection, and intrathecal injection (injection through the sheath meninges around the spinal cord into the subarachnoid space).

drug route when enter body

Drug enters body by chosen route
• Absorbed into blood or acts at local site
• Travels in the bloodstream
• Arrives at site of action
• Exerts its effect
• Is metabolized into inactive compounds
• Is excreted from the body

drug route

oral tablet, capsule, liquid
• Sublingual
• Subcutaneous injection
• Intramuscular injection
• Intravenous injection –fasted method of
drug administration
• Inhalation
• Iontophoretical - the application of an
electrical current to promote transdermal
drug delivery for inflammation
• Topical (gel, cream, spray, liquid)
• Transdermal - patch
• Suppository
• Intrathecal - spinal cord into
subarachnoid space

Oral medication

Absorbed from stomach or intestine
– Transported to the liver
– Released into general circulation

Intramuscular injection

Gradually absorbed into the blood
– Blood transports drug

Drug Mechanisms and Receptors

Common pharmacologic action requires drug-receptor interaction

Drugs may stimulate receptors
directly.
• Drugs may block receptor site for
normal chemicals of the body
• Specificity of drug dependent on
mode of action
• Drugs that interact with several
metabolic pathways or common
functions are likely to have greater
side effects.

drug excreted

Most drugs are metabolized and
inactivated in the liver and then
excreted by the kidneys.
• Some drugs are excreted in bile or
feces
• Some drugs (anesthetics) are
expired through the lungs
• Some barriers to drug passage exist
• Many drugs cannot pass the blood-
brain barrier
• Placental barrier protects the fetus

Prescription―

a signed legal
document that must include the
following:
– Patient’s name, address, and age (if
significant)
– Prescriber’s name, address, and
identification number
– Date
– Name and amount of the drug
– Dosage (mg and mL)
– Route and directions for using the
drug
– Permission for additional quantities

Generic name:

unique, official, simple name for a specific drug

For example- ASA

Trade

, proprietary, or brand name:
assigned by single manufacturer

For example – Aspirin

Chemical name:

chemical
component

For example – acetylsalicylic acid

U.S. Food and Drug Administration

Regulates the production, labeling,
distribution, and other aspects of
drug control

Scheduled drugs

Drugs considered to have a risk for
potential adverse side effects, abuse,
or dependency

Over-the-counter (OTC) drugs

Available without prescription

Drug Development

Drugs may be added or moved
between schedules
• It takes 10 – 15 years for
development of a new drug with early
trials of few patients and trial group is
expanded if successful
• Project design – divide patients
randomly into 2 groups with one
group receiving standard drug
therapy (check effectiveness and
safety) and one group receives
placebo or “sugar” pill (no active
ingredient)

• Schedule I –

high probability for
abuse , no therapeutic use Example:
Heroin, LSD
- drugs can be used for research

Schedule II –

High probability of
abuse, therapeutic use or accept for
therapy under close restrictions
Example: raw opium, morphine,
methadone
- require written, signed
prescription

Schedule III –

low potential for abuse
compared to I and II. Therapeutic
uses accepted for treatment in US,
low potential for dependence
Example: barbituates with reduced
concentration of morphine
- requires a prescription, but can
be ordered by telephone

Schedule IV:

Less potential for abuse
than III, reduced potential for
physical/psychological dependency
than III Example: diazepam

Schedule V:

Less potential for abuse
or dependency than IV Example:
codeine

Classifications
of Drugs

depressants
• Hallucinogens
• Inhalants
• Narcotics
• Steroids
• Stimulants

Physiotherapy

Assesses physical function
• Works to reduce pain, restore any
deficit and prevent further physical
dysfunction
• Involves individualized treatment and
rehabilitation
• Rehab and LTC to focus on
maximizing mobility and functional
independence
• Work with amputees, spinal cord
injuries, brain injuries

Physiotherapy may include the
following:
– Appropriate exercise
– Use of ultrasound
– Transcutaneous electrical nerve
stimulation (TENS)
– Other methods to alleviate pain,
increase function

Physiotherapist

treats acute injuries as well as
chronic conditions
• Educating patients and families to
assist and maintain individual
programs
• Practice includes the following:
– Pain disorders
– Acute neurologic disorders
– Musculoskeletal disorders
– Cardiopulmonary disorders
– Infants with congenital abnormalities
– Children and adults with injuries that
affect mobility

Occupational Therapy

Provides functional assessment related to normal activities of
daily living (ADL)
• Provides guidance and practical assistance to maintain independence
• Integrates remediation of motor control, cognition, and visual-spatial perception
– Necessary for patient safety
• Teaches use of adaptations for specific needs (for food prep,feeding, and personal hygiene)
• Assesses technologies available for use in home and workplace

Speech and Language Pathologist

Assesses and treats those with communication or swallowing
problems
• Patients may include the following:
– Infant with swallowing and feeding problems
– Child with hearing deficit who is mute
– Adult with aphasia following a stroke
– Child with delayed speech
– Individual with dysarthria

Nutritionist Dietitian

Expert in nutritional needs of the
body in health and illness
• Advises on nutritional needs and
food management suited to a specific
diagnosis
– Example: diabetes
• Supervises food services in hospitals
and other health care institutions
• May consult on the dangers of
extreme diets and eating disorders

Registered Massage Therapist

Uses a variety of massage
techniques to:
– Increase circulation
– Reduce pain
– Increase flexibility for patients with
joint pain or problems with body
alignment
– May use:
• Soothing aromatics
• Acupuncture
• Other modalities

Osteopath

Osteopaths are medically licensed
doctors in many jurisdictions.
• Uses many medical treatment
methods
• In addition, an osteopath:
– Promotes body’s natural healing
processes by incorporating
manipulations of the musculoskeletal
system (e.g., use of chest percussion
to relief respiratory congestion)

Chiropractic

Based on the concept that one’s
health status is dependent on the
state of the nervous system
• Frequently involves manipulations of
the vertebral column
• May involve deep tissue massage,
acupressure, and/or acupuncture
• Radiology may be used for
diagnosis.
• No drugs or surgery

Holistic:

approach recognizing
interrelationships of body, mind, and
spirit

Noncontact Therapeutic Touch

Energy is exchanged between
people for relief of pain and anxiety
and to promote healing.
• Consciously forms a positive intent to
heal
• Location of problem areas by
scanning body with the hands
– Healing is promoted by lightly
touching the skin or moving the
hands just above the body surface.
• Imagery, light, or colors may be
incorporated to transfer healing
energy to patient, bringing comfort

Naturopathy

Treatment based on the following:
– Promoting natural foods
– Massage
– Exercise
– Fresh air
– Acupuncture
– Herbal compounds
– Nutrition
– Physical manipulations
Acupuncture, massage, herbals,
nutrition can be included as part of the
treatment. Do not recommend any
traditional drugs.

Homeopathy

Goal is to stimulate the immune
system and natural healing powers of
the body by use of the following:
– Plant products
– Animal products
– Mineral products
– Offending toxic substance is
identified for each disease state.
• Diluted several thousand-fold
• The diluted toxin is then
administered to treat the problem.

Herbalism

First documented in ancient Egypt
• Use of herbs and plants for treatment
of acute conditions or prevention of
disease
- Garlic – cardiovascular disease
- Echinacea – cold remedies,
prophylaxis
• Efforts are being focused on the
following:
– Providing standardized content
– Providing efficacy
– Improving purity

Aromatherapy

Uses essential oils that have
therapeutic effects
• Thought to act on neural pathways
through the olfactory system
• Oils may be
– Absorbed through the skin into the
general circulation
• When bathing
• With massage
– Inhaled
chamomile – calming and sleep-
inducing
lavender – soothe headache
rosemary – relieves muscles

Asian Concepts of Disease and Healing

Based on balance or imbalance of
life energy―qi or chi
• Disease is caused by a deficit or
excess of qi or chi (chee) and healing
restores the energy balance
• Qi is derived from three sources:
– Inherited or ancestral factors
– Food ingested
– Air breathed in

Qi flows along specific
channels―meridians.
– All organs and body parts are
connected.
– Each meridian has name and
function and may be located a
distance from the organ for which it is
named
– Most meridians are bilateral
– Qi flows along the meridians and flow
can be altered or accessed at
acupoints
– Each acupoint as specific actions
such as moving qi or blood, pain
reduction, heating, cooling, calming
emotions
– Pattern of disharmony may involve a
number of acupoints and meridians
Goal is to connect with points that will
normalize flow of qi and restore
balance of yin and yang

Shiatsu –

Japanese – acupuncture
without needles; finger pressure
– Uses slow, deep, gentle pressure
(thumbs, fingers, palms, elbows,
knees) to specific points to access
tsubo or acupoints
– Often used for stress-related illness
and back pain; provides relaxation

acupuncture

increases energy, function; blocks
pain pathways
– Involves Inserting fine needles into
the various meridian acupoints (365)
• Each point has specific and
generalized therapeutic actions.
– Treatment on average uses 5 to 15
needles connected to low level
electric current or laser for 30-35
minutes. May use ultrasonic waves
or laser over needles for acupoints
– Acupuncture decreases pain
because it causes release of
endorphins in brain

Yoga

Combines physical activity in the
form of stretching postures with
meditation
– Improves flexibility, muscle tone,
endurance, overall health; reduces
stress
– May relieve pain and anxiety in
chronically ill patients

Reflexology

Relates points on feet and hands to
10 longitudinal zones in the body
– Practitioner uses varying degrees of
pressure.
– Relieves stress and muscle tension

Craniosacral therapy

Used by a variety of health care
practitioners
– Therapy deals with the pulsing
rhythm of cerebrospinal fluid around
brain and spinal cord
– Gentle palpation and manipulation of
skull and vertebrae to rebalance
system
– Many studies haven’t been able to
prove healing effects of this therapy