Mode of Action, Symptoms, and Treatments

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Mode of Action, Symptoms, and Treatments

OBJECTIVES/RATIONALE

An essential component of Pharmacology is the potential toxicity of medications and their actions on the different body systems. The student will interpret technical material related to pharmacology, and identify side effects, toxic effect, and adverse reactions of drugs.

TEKS: 121.25

1C, 3B, 5D TAKS ELA 1, 3, 4, 5, 6

Science 2

KEY POINTS

I.

II.

Effects of Medication

A.

Therapeutic Effects

1.

Desired or intended effects refer to the primary purpose of prescribing

2.

and administrating medication.

Medication is a substance with therapeutic value used in treating a disease or disorder.

B.

Side Effects are unintended or secondary effects.

1.

2.

May not be harmful.

May permit the drug to be used for a secondary purpose.

C.

D.

Adverse Effects are undesired effects that may be harmful.

1.

may damage function of vital organs over prolonged time.

2.

may be minimized by reducing dosage or switching medication.

Toxic Effects can be extremely harmful. Sometimes they can be life threatening; implies drug poisoning.

1.

Poison is any substance which, when ingested, inhaled or absorbed, or when applied to, injected into, or developed within the body, in

A.

2.

relatively small amounts, by its chemical action may cause damage to structure or disturbance of function. toxin is a poison; frequently used to refer specifically to a protein produced by some higher plants, certain animals, and pathogenic bacteria, which is highly toxic for other living organisms. Such substances are differentiated from the simple chemical poisons and the vegetable alkaloids by their high molecular weight and

3.

4.

5.

antigenicity. toxicity is the quality of being poisonous, especially the degree of virulence of a toxic micron or of a poison.

Drug must be stopped.

Additionally may require supportive treatment and administration of antidotes.

Causes of Adverse and Toxic Effects

All drugs are potentially dangerous

B.

C.

D.

E.

F.

III.

A.

1.

Many medications used for everyday illnesses or chronic diseases are considered as harmless, especially if OTC.

2.

3.

OTCs perceived generally to be safe since no prescription is required.

Prescribed medications are assumed to be safe since physician would not prescribe something that might harm the patient.

4.

Lack of understanding - drugs can cause toxicity even if taken as directed

Overdose is taking more than prescribed or advised.

1.

Accidentally

2.

Age

1.

Purposeful

Child may be unable to metabolize at needed rate if dose too large,

2.

e.g. parent giving adult dose of Tylenol. elderly, metabolism slowed down, organs (liver, kidneys) not working at full capacity – drug levels can build up, eventually leading to toxic levels.

Disease

1.

Weakens or impairs function of organs causing drugs not to be

2.

metabolized at efficient rate, potentially leading to toxic buildup a.

liver – cannot metabolize drugs at most efficient rate b.

kidneys – cannot excrete substances at most efficient rate

Some medications cause the organs to be weakened, sometimes to the point of complete failure (may be temporary)

Drug Interactions

1.

2.

3.

may react with other drugs creating toxic substances when combined may react with another drug potentiating the effect. medication may interact with certain foods, leading to toxic buildup

4.

a.

b.

slowing down metabolizing of drug

preventing metabolizing of drug

combining with drug causing toxic substances to devel

Allergies - patient’s reactivity is altered due to previous contact with drug acting as antigen or allergen.

1.

Unpredictable a.

b.

May develop after drug has already been taken for some time.

May be idiosyncratic; no known reason as to why patient reacts

2.

3.

4.

this way to drug. not dose-related can cause serious toxicity may be caused by combination with other substances, intentional or not symptoms vary largely 5.

Treatment

Overdose and Toxic Effect

1.

2.

inducing emesis gastric lavage

3.

activated charcoal

B.

C.

IV.

A.

B.

4.

5.

6.

in some cases reducing drug levels may be sufficient, e.g. in gentamycin reduce dosage and frequency intermittent discontinuation of drug until serum levels back within normal range.

Allergies – the drug must be stopped or discontinued until sensitivity testing is completed.

Supportive Treatment

1.

kidney dialysis in case of renal failure

2.

3.

4.

administration of antidotes mechanical ventilation administration of drug-binding agents, e.g. Digibind for digitalis

Prevention education of patient

1.

2.

3.

expected effects symptoms of unexpected effects need for monitoring of serum levels, e.g. digitalis a.

b.

c.

d.

e.

anticoagulants some antibiotics, e.g. gentamycin, amikacin lithium phenobarbitol

Safety

1.

2.

child resistant containers or caps take medication as prescribed

ACTIVITIES

I.

II.

III.

Attend presentation of a representative from the local Poison Control Center.

Research, identify, and classify medications according to their potential toxic effects on the different organs and body systems.

Create a table listing common toxic substances, specifically medications, the signs and symptoms of toxicity, and their antidotes, including effective household remedies.

MATERIALS NEEDED

Poison Control Center

Internet

Library

ASSESSMENT

Project Rubric

ACCOMMODATIONS

For reinforcement the student will design a poster depicting toxic dangers of medications

(prescription and non-prescription).

For enrichment the student will prepare and present a community education session on the potential toxic effects of medications, the drugs most at risk, the signs and symptoms to recognize, the ways to prevent toxicity, and the required interventions. Use any audiovisual means of communication (video, public speaking, posters, pamphlets, slides, etc.)

REFLECTIONS

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