Glossary of Key Terms in Pharmacology, Clinical Conditions, and Associated Signs and Symptoms

by: ishi21marie, RN

acute dystonia – extrapyramidal symptom manifested by abnormal posturing, grimacing, spastic torticollis (neck torsion), and oculogyric (eyeball movement) crisis.

adverse effect – unintended, unpredictable, and nontherapeutic response to drug action. Adverse effects occur at doses used therapeutically or for prophylaxis or diagnosis. They generally result from drug toxicity, idiosyncrasies, or hypersensitivity reactions caused by the drug itself or by ingredients added during manufacture, e.g., preservatives, dyes, or vehicles.

afterload – resistance that ventricles must work against to eject blood into the aorta during systole.

agranulocytosis – sudden drop in leukocyte count; often followed by a severe infection manifested by high fever, chills, prostration, and ulcerations of mucous membrane such as in the mouth, rectum, or vagina.

akathisia – extrapyramidal symptom manifested by a compelling need to move or pace, without specific pattern, and an inability to be still.

analeptic – restorative medication that enhances excitation of the CNS without affecting inhibitory impulses.

anaphylactoid reaction – excessive allergic response manifested by wheezing, chills, generalized pruritic urticaria, diaphoresis, sense of uneasiness, agitation, flushing, palpitations, coughing, difficulty breathing, and cardiovascular collapse.

anticholinergic actions – inhibition of parasympathetic response manifested by dry mouth, decreased peristalsis, constipation, blurred vision, and urinary retention.

bioavailability – fraction of active drug that reaches its action sites after administration by any route. Following an IV dose, bioavailability is 100%; however, such factors as first-pass effect, enterohepatic cycling, and biotransformation reduce bioavailability of an orally administered drug.

blood dyscrasia – pathological condition manifested by fever, sore mouth or throat, unexplained fatigue, easy bruising or bleeding.

cardiotoxicity – impairment of cardiac function manifested by one or more of the following: hypotension, arrhythmias, precordial pain, dyspnea, electrocardiogram (ECG) abnormalities, cardiac dilation, congestive failure.

cholinergic response – stimulation of the parasympathetic response manifested by lacrimation, diaphoresis, salivation, abdominal cramps, diarrhea, nausea, and vomiting.

circulatory overload – excessive vascular volume manifested by increased central venous pressure (CVP), elevated blood pressure, tachycardia, distended neck veins, peripheral edema, dyspnea, cough, and pulmonary rales.

CNS stimulation – excitement of the CNS manifested by hyperactivity, excitement, nervousness, insomnia, and tachycardia.

CNS toxicity – impairment of CNS function manifested by ataxia, tremor, incoordination, paresthesias, numbness, impairment of pain or touch sensation, drowsiness, confusion, headache, anxiety, tremors, and behavior changes.

Congestive Heart Failure (CHF) – impaired pumping ability of the heart manifested by paroxysmal nocturnal dyspnea, cough, fatigue or dyspnea on exertion, tachycardia, peripheral or pulmonary edema, and weight gain.

Cushing’s syndrome – fatty swellings in the interscapular area (buffalo hump) and in the facial area (moon face), distension of the abdomen, ecchymoses following even minor trauma, impotence, amenorrhea, high blood pressure, general weakness, loss of muscle mass, osteoporosis, and psychosis.

dehydration – decreased intracellular or extracellular fluid manifested by elevated temperature, dry skin and mucous membranes, decrease tissue turgor, sunken eyes, furrowed tongue, low blood pressure, diminished or irregular pulse, muscle or abdominal cramps, thick secretions, hard feces and impaction, scant urinary output, urine specific gravity above 1.030, an elevated hemoglobin.

disulfiram-type reaction – Antabuse-type reaction manifested by facial flushing, pounding headache, sweating, slurred speech, abdominal cramps, nausea, vomiting, tachycardia, fever, palpitations, drop in blood pressure, dyspnea, and sense of chest constriction. Symptoms may last up to 24 hours.

enzyme induction – stimulation of microsomal enzymes by a drug resulting in its accelerated metabolism and decreased activity. If reactive intermediates are formed, drug-mediated toxicity may be exacerbated.

first-pass effect – reduced bioavailability of an orally administered drug due to metabolism in GI epithelial cells and liver or to biliary excretion. Effect may be avoided by use of sublingual tablets or rectal suppositories.

fixed drug eruption drug-induced circumscribed skin lesion that persists or recurs in the same site. Residual pigmentation may remain following drug withdrawal.

half-life (t½) – time required for concentration of a drug in the body to decrease by 50%. Half-life also represents the time necessary to reach steady state or to decline from steady state after a change (i.e., starting or stopping) in the dosing regimen. Half-life may be affected by a disease state and age of the drug user.

heat stroke – a life-threatening condition manifested by absence of sweating; red, dry, hot skin; dilated pupils; dyspnea; full bounding pulse; temperature above 40° C (105° F); and mental confusion.

hepatic toxicity – impairment of liver function manifested by jaundice, dark urine, pruritus, lightcolored stools, eosinophilia, itchy skin or rash, and persistently high elevations of alanine amino-transferase (ALT) and aspartate aminotransferase (AST).

hyperammonemia – elevated level of ammonia or ammonium in the blood manifested by lethargy, decreased appetite, vomiting, asterixis (flapping tremor), weak pulse, irritability, decreased responsiveness, and seizures.

hypercalcemia – elevated serum calcium manifested by deep bone and flank pain, renal calculi, anorexia, nausea, vomiting, thirst, constipation, muscle hypotonicity, pathologic fracture, bradycardia, lethargy, and psychosis.

hyperglycemia – elevated blood glucose manifested by flushed, dry skin, low blood pressure and elevated pulse, tachypnea, Kussmaul’s respirations, polyuria, polydipsia; polyphagia, lethargy, and drowsiness.

hyperkalemia – excessive potassium in blood, which may produce lifethreatening cardiac arrhythmias, including bradycardia and heart block, unusual fatigue, weakness or heaviness of limbs, general muscle weakness, muscle cramps, paresthesias, flaccid paralysis of extremities, shortness of breath, nervousness, confusion, diarrhea, and GI distress.

hypermagnesemia – excessive magnesium in blood, which may produce cathartic effect, profound thirst, flushing, sedation, confusion, depressed deep tendon reflexes (DTRs), muscle weakness, hypotension, and depressed respirations.

hypernatremia – excessive sodium in blood, which may produce confusion, neuromuscular excitability, muscle weakness, seizures, thirst, dry and flushed skin, dry mucous membranes, pyrexia, agitation, and oliguria or anuria.

hypersensitivity reactions – excessive and abnormal sensitivity to given agent manifested by urticaria, pruritus, wheezing, edema, redness, and anaphylaxis.

hyperthyroidism – excessive secretion by the thyroid glands, which increases basal metabolic rate, resulting in warm, flushed, moist skin; tachycardia, exophthalmos; infrequent lid blinking; lid edema; weight loss despite increased appetite; frequent urination; menstrual irregularity; breathlessness; hypoventilation; congestive heart failure; excessive sweating.

hyperuricemia – excessive uric acid in blood, resulting in pain in flank; stomach, or joints, and changes in intake and output ratio and pattern.

hypocalcemia – abnormally low calcium level in blood, which may result in depression; psychosis; hyperreflexia; diarrhea; cardiac arrhythmias; hypotension; muscle spasms; paresthesias of feet, fingers, tongue; positive Chvostek’s sign. Severe deficiency (tetany) may result in carpopedal spasms, spasms of face muscle, laryngospasm, and generalized convulsions.

hypoglycemia – abnormally low glucose level in the blood, which may result in acute fatigue, restlessness, malaise, marked irritability and weakness, cold sweats, excessive hunger, headache, dizziness, confusion, slurred speech, loss of consciousness, and death.

hypokalemia – abnormally low level of potassium in blood, which may result in malaise, fatigue, paresthesias, depressed reflexes, muscle weakness and cramps, rapid, irregular pulse, arrhythmias, hypotension, vomiting, paralytic ileus, mental confusion, depression, delayed thought process, abdominal distension, polyuria, shallow breathing, and shortness of breath.

hypomagnesemia – abnormally low level of magnesium in blood, resulting in nausea, vomiting, cardiac arrhythmias, and neuromuscular symptoms (tetany, positive Chvostek’s and Trousseau’s signs, seizures, tremors, ataxia, vertigo, nystagmus, muscular fasciculations).

hypophosphatemia – abnormally low level of phosphates in blood, resulting in muscle weakness, anorexia, malaise, absent deep tendon reflexes, bone pain, paresthesias, tremors, negative calcium balance, osteomalacia, osteoporosis.

hypothyroidism – condition caused by thyroid hormone deficiency that lowers basal metabolic rate and may result in periorbital edema, lethargy, puffy hands and feet, cool, pale skin, vertigo, nocturnal cramps, decreased GI motility, constipation, hypotension, slow pulse, depressed muscular activity, and enlarged thyroid gland.

hypoxia – insufficient oxygenation in the blood manifested by dyspnea, tachypnea, headache, restlessness, cyanosis, tachycardia, dysrhythmias, confusion, decreased level of consciousness, and euphoria or delirium.

International Normalizing Ratio – measurement that normalizes for the differences obtained from various laboratory readings in the value for thromboplastin blood level.

leucopenia – abnormal decrease in number of white blood cells, usually below 5000 per cubic millimeter, resulting in fever, chills, sore mouth or throat, and unexplained fatigue.

liver toxicity – manifested by anorexia, nausea, fatigue, lethargy, itching, jaundice, abdominal pain, dark-colored urine, and flu-like symptoms.

metabolic acidosis – decrease in pH value of the extracellular fluid caused by either an increase in hydrogen ions or a decrease in bicarbonate ions. It may result in one or more of the following: lethargy, headache, weakness, abdominal pain, nausea, vomiting, dyspnea, hyperpnea progressing to Kussmaul breathing, dehydration, thirst, weakness, flushed face, full bounding pulse, progressive drowsiness, mental confusion, combativeness.

metabolic alkalosis – increase in pH value of the extracellular fluid caused by either a loss of acid from the body (e.g., through vomiting) or an increased level of bicarbonate ions (e.g., through ingestion of sodium bicarbonate). It may result in muscle weakness, irritability, confusion, muscle twitching, slow and shallow respirations, and convulsive seizures.

microsomal enzymes – drug-metabolizing enzymes located in the endoplasmic reticulum of the liver and other tissues chiefly responsible for oxidative drug metabolism, e.g., cytochrome P450.

myopathy – any disease or abnormal condition of striated muscles manifested by muscle weakness, myalgia, diaphoresis, fever, and reddish-brown urine (myoglobinuria) or oliguria.

nephrotoxicity – impairment of the nephrons of the kidney manifested by one or more of the following: oliguria, urinary frequency, hematuria, cloudy urine, rising BUN and serum creatinine, fever, graft tenderness or enlargement.

Neuroleptic Malignant Syndrome (NMS) – potentially fatal complication associated with antipsychotic drugs manifested by hyperpyrexia, altered mental status, muscle rigidity, irregular pulse, fluctuating BP, diaphoresis, and tachycardia.

orphan drug – (as defined by the Orphan Drug Act, an amendment of the Federal Food, Drug, and Cosmetic Act which took effect in January 1983): drug or biological product used in the treatment, diagnosis, or prevention of a rare disease. A rare disease or condition is one that affects fewer than 200,000 persons in the United States, or affects more than 200,000 persons but for which there is no reasonable expectation that drug research and development costs can be recovered from sales within the United States.

ototoxicity – impairment of the ear manifested by one or more of the following: headache, dizziness or vertigo, nausea and vomiting with motion, ataxia, nystagmus.

prodrug – inactive drug form that becomes pharmacologically active through biotransformation.

protein binding – reversible interaction between protein and drug resulting in a drug-protein complex (bound drug) which is in equilibrium with free (active) drug in plasma and tissues. Since only free drug can diffuse to action sites, factors that influence drug-binding (e.g., displacement of bound drug by another drug, or decreased albumin concentration) may potentiate pharmacological effect.

pseudomembranous enterocolitis – life-threatening superinfection characterized by severe diarrhea and fever.

pseudoparkinsonism – extrapyramidal symptom manifested by slowing of volitional movement (akinesia), mask facies, rigidity and tremor at rest (especially of upper extremities); and pill rolling motion.

pulmonary edema – excessive fluid in the lung tissue manifestied by one or more of the following: shortness of breath, cyanosis, persistent productive cough (frothy sputum may be blood tinged), expiratory rales, restlessness, anxiety, increased heart rate, sense of chest pressure.

renal insufficiency – reduced capacity of the kidney to perform its functions as manifested by one or more of the following: dysuria, oliguria, hematuria, swelling of lower legs and feet.

serotonin syndrome – manifested by restlessness, myoclonus, mental status changes, hyperreflexia, diaphoresis, shivering, and tremor.

somogyi effect – rebound phenomenon clinically manifested by fasting hyperglycemia and worsening of diabetic control due to unnecessarily large p.m. insulin doses. Hormonal response to unrecognized hypoglycemia (i.e., release of epinephrine, glucagon, growth hormone, cortisol) causes insensitivity to insulin. Increasing the amount of insulin required to treat the hyperglycemia intensifies the hypoglycemia.

superinfection – new infection by an organism different from the initial infection being treated by antimicrobial therapy manifested by one or more of the following: black, hairy tongue; glossitis, stomatitis; anal itching; loose, foul-smelling stools; vaginal itching or discharge; sudden fever; cough.

tachyphylaxis – rapid decrease in response to a drug after administration of a few doses. Initial drug response cannot be restored by an increase in dose.

tardive dyskinesia – extrapyramidal symptom manifested by involuntary rhythmic, bizarre movements of face, jaw, mouth, tongue, and sometimes extremities.

vasovagal symptoms – transient vascular and neurogenic reaction marked by pallor, nausea, vomiting, bradycardia, and rapid fall in arterial blood pressure.

water intoxication (dilutional hyponatremia) – less than normal concentration of sodium in the blood resulting from excess extracellular and intracellular fluid and producing one or more of the following: lethargy, confusion, headache, decreased skin turgor, tremors, convulsions, coma, anorexia, nausea, vomiting, diarrhea, sternal fingerprinting, weight gain, edema, full bounding pulse, jugular vein distension, rales, signs and symptoms of pulmonary edema.

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