Pharmacology: Module 1 (Nursing Process)

Nursing Process

Steps in the nursing process: Assessment, Analysis, Planning, Nursing interventions, Evaluation.

Clinical Judgment

The ability to recognize cues, analyze cues, prioritize hypotheses, generate solutions, take action, and evaluate outcomes.

Recognize cues

Identifying subjective and objective data.

Analyze cues and prioritize hypothesis

The process of analyzing cues and prioritizing patient problems.

Generate solutions

Identifying expected outcomes that are patient-centered, measurable, realistic, acceptable to both patient and nurse, and dependent on the patient's decision-making ability.

Take action

Involves patient teaching, addressing general information, side effects, self-administration, and assessing diet.

Evaluate outcomes

Determining if interventions and outcomes were met, if interventions were effective, ineffective, or made no difference, and documenting successful goal attainment.

ANA Code of Ethics

Developed as a guide for carrying out nursing responsibilities consistent with quality in nursing care and ethical obligations of the profession, adopted in 1950 and revised in 2015.

The Nurse's role in clinical research

Responsible for patient safety and integrity of research protocol.

Drug Standards

Includes the United States Pharmacopeia and the National Formulary, and is governed by federal legislation and Nurse Practice Acts.

U.S. Drug Enforcement Administration (DEA)

Responsible for drug scheduling and regulation.

Drug Names

Includes chemical names, generic names (required for NCLEX and exams), and brand/trade names.

Over-the-Counter Drugs

Drugs found to be safe and appropriate for use without direct supervision of a healthcare provider, available without a prescription.

FDA standardized OTC labeling

Implemented in 2002 to provide consumers with better information about benefits and risks of OTC drugs.

Pharmacokinetics

The study of drug movement through the body and what the body does to the drug, involving four processes: absorption, distribution, metabolism, excretion.

Pharmacodynamics

What the drug does to the body as it moves throughout the body, involving receptor binding, postreceptor effects, and chemical reactions.

Drug absorption

The movement of the drug from the GI tract into the bloodstream, involving disintegration and dissolution.

First Pass Effect

The process of drug movement from the GI tract to the liver via the portal vein.

Drug response relationship

The body's physiologic response to changes in drug concentration at the site of action.

Potency

The amount of drug needed to produce a specific effect.

Maximal efficacy

The maximum effect that can be achieved with a drug.

Therapeutic index

The ratio of the toxic dose to the therapeutic dose of a drug.

Onset

The time it takes for a drug to reach minimum effective concentration.

Peak

The highest concentration of a drug in the blood.

Duration

The length of time a drug exerts a therapeutic effect.

Peak drug level

highest plasma concentration of drug at a specific time

Trough drug level

lowest plasma concentration of drug

Agonists

Activate receptors and produce desired response

Partial Agonists

Elicit only moderate activity when binding to receptors and prevent receptor activation by other drugs

Antagonists

Prevent receptor activation and block response

Side effects

Secondary drug effects that can be mild to severe, unintentional, and unexpected

Adverse reactions

Undesirable effects that can range from mild to severe

Drug toxicity

Drug level exceeds therapeutic range

Tolerance

Decreased responsiveness to drug over course of therapy, requiring higher dose to achieve same therapeutic response

Tachyphlaxis

Acute, rapid decrease in response to a drug

Placebo effect

Drug response not attributed to drug's chemical properties

Additive drug effects

Sum of effects of two drugs

Synergistic drug effects

Effect of two drugs is much greater than effects of either drug alone

Antagonistic drug effects

One drug reduces or blocks effect of the other drug

Drug-nutrient interactions

Food may increase, decrease, or delay drug response

Drug-laboratory interactions

Drugs may cause misinterpretation of test results

Drug-induced photosensitivity

Drug induced skin reaction caused by sunlight exposure

Pharmacogenetics

Study of how a patient's genomes affect drug response, helping individualize optimal drug treatment regimens

Total body water (TBW)

60% of body weight in adults

Intracellular fluid

Fluid within cells

Extracellular fluid (ECF)

Fluid outside of cells, including interstitial fluid and intravascular fluid

Edema

Accumulation of fluid within the interstitial spaces caused by various factors

Sodium (Na+)

Primary ECF cation that regulates osmotic balance and nerve impulse conduction

Chloride (Cl-)

Primary ECF anion that regulates osmotic balance and plays a role in acid-base balance

Renin-angiotensin-aldosterone system

System that controls Na concentration through aldosterone

ADH (antidiuretic hormone)

Hormone that maintains water balance

Hypernatremia

H2O deficit in ECF (dehydration), most commonly caused by fluid loss or excess IV fluids

Hypotonic alterations

Alterations in osmolality leading to conditions such as Hyponatremia.

Hyponatremia

H2O excess in ECF resulting in cerebral edema.

Fluid Replacement

General considerations include all routes of fluid intake and loss.

Daily H2O Requirements

Fluid intake needs based on patient's weight and caloric needs.

Types of intravenous solutions

Includes crystalloids and colloids.

Crystalloids

Used for short-term maintenance therapy to treat dehydration and electrolyte imbalance.

Colloids

Plasma expanders that contain protein and large molecules to increase osmolarity.

Hypochloremia

Characterized by cues such as tremors and twitching.

Hyperchloremia

Characterized by cues such as weakness and lethargy.

Potassium (K+)

Normal range is 3.5 to 5.0 mEq/L; major intracellular cation that regulates electrical neutrality.

Hypokalemia

Potassium level <3.5 mEq/L with manifestations depending on heart rate and severity.

Hyperkalemia

Potassium level >5.0 mEq/L; rare due to efficient renal excretion.

Hyperkalemia Treatment

Includes potassium restriction, intravenous sodium bicarbonate, and calcium gluconate 10%.

Prototype Drug: Potassium Chloride (KCL)

Used for electrolyte replacement; must be diluted if given IV and monitored for ECG changes.

Calcium

Normal range is 8.6 to 10.2 mg/dl; most abundant mineral important for bone formation and nerve transmission.

Hypocalcemia

Ca level < 8.6 mg/dL caused by inadequate dietary intake or intestinal absorption.

Hypercalcemia

Calcium level > 10.2 mg/dL; Increased calcium concentration.

Causes of Hypercalcemia

Hyperparathyroidism, bone metastases, steroids, multiple fractures.

Effects of Hypercalcemia

Fatigue, muscle weakness, impaired renal function, kidney stones.

Prototype Drug: Calcium

Used for electrolyte replacement; caution for IV infiltration and enhanced digoxin effects.

Calcium Preparations

Calcium Gluconate, Calcium Chloride.

Side Effects of Calcium

Nausea/vomiting, constipation, pain.

Adverse Effects of Calcium

ECG changes, renal failure, cardiac arrest.

Clinical Judgment: Calcium - Concept

Fluid and electrolyte balance; check serum calcium levels and assess for signs of calcium imbalance.

Clinical Judgment: Calcium - Generate Solutions

Monitor serum total calcium & ionized calcium levels (4.5 - 5.6 mg/dL); monitor vital signs & report abnormal findings.

Phosphate

Normal levels 2.4 - 4.4 mg/dL; provides energy for muscle contraction and acid-base balance.

Hypophosphatemia

Phosphate concentration < 2.4 mg/dL; causes include intestinal malabsorption related to vitamin D.

Signs & Symptoms of Hypophosphatemia

Muscle weakness, tremors, paresthesia, bone pain.

Hyperphosphatemia

Phosphate concentration > 4.4 mg/dL; causes include acute & chronic renal failure.

Effects of Hyperphosphatemia

Symptoms related to low serum calcium levels; calcification of soft tissues with prolonged condition.

Magnesium

Normal levels 1.5 to 2.5 mEq/L; intracellular cation involved in neuromuscular excitability and cardiac contractions.

Hypomagnesemia

Magnesium concentration < 1.5 mEq/L; causes include malnutrition, malabsorption syndromes, alcoholism.

Effects of Hypomagnesemia

Behavioral changes, irritability, increased reflexes, tachycardia, digoxin toxicity.

Hypermagnesemia

Magnesium concentration > 2.5 mEq/L; causes include renal insufficiency or failure, antacids & laxatives.

Effects of Hypermagnesemia

Skeletal smooth muscle contraction, loss of deep tendon reflexes, nausea & vomiting.

Acid-Base Balance

Low concentration of H+ ions is 'basic'; high concentration of H+ ions is 'acidic'.

Buffer Systems

Chemicals that bind excessive H+ or OH- without a significant change in pH.

Bicarbonate-Carbonic Acid Buffering

CO2 + H2O = H2CO3; carbonic acid dissociates to form H+ and bicarbonate.

Acid-Base Imbalances

Acidosis: systemic increase in H+ concentration or decrease in bicarbonate; Alkalosis: systemic decrease in H+ concentration or increase in bicarbonate.

Metabolic Acidosis

Low pH & low HCO3; example: diabetic ketoacidosis (DKA).

Respiratory Acidosis

Low pH, high PaCO2; caused by alveolar hypoventilation.

Respiratory Alkalosis

High pH, low PaCO2; caused by alveolar hyperventilation.