Pharmacology Basics Adapted from NurseCE4less.com for Ambercare Corporation Education Department, 2014 • Describe the role of receptors related to medications • Discuss the four components of pharmacokinetics • Describe how medications are classified • Identify medication classifications, actions, uses, adverse reactions, side effects, contraindications and implications OBJECTIVES • HOW Tylenol knows to go to your head when you have a headache and to your elbow when you have “tennis elbow”? • OR how one or two small tablets containing only 5001000 mg of active drug can relieve a headache or ease the inflammation from a strained muscle or tendon in a 185 pound athlete? DID YOU EVER WONDER…? • Pharmacokinetic Process: • • • • Absorption Distribution Metabolism Excretion Basic principles of pharmacology includes… • Medication management help patients by: • Curing disease or infection, relieving symptoms such as pain or nausea • Can also have the reverse effect: • In terms of: • • • • Allergic reaction Overdose Adverse reaction Administering wrong medication Patient safety is paramount! • Medications are distributed throughout the body by the blood and other fluids of distribution • Once they (the med) arrives at it’s proper site of action, they act by binding to receptors, usually located on the outer membrane of cells or enzymes located within the cell • Receptors are like biological “light switches” which turn on and off when stimulated by a drug which binds to the receptor and activates it Receptors – function? • Narcotics (Opioids) – like Morphine bind to receptors in the brain that sense pain and decrease the intensity of that perception • Antiplatelets (ASA); NSAIDs (Advil) or Antipyretics (Tylenol) bind to an enzyme located in the cells outside the brain close to where the pain is localized (e.g., hand, foot, low back, BUT NOT IN THE BRAIN) – thereby decreasing the formation of biologically-active substances known as prostaglandins, which cause pain and inflammation Receptors • Food for thought! • In some instances – a drug’s “site of action” or “receptor” may actually be something that resides within the body – but is not anatomically part of the body – • i.e., Tums – the site of action is the acid in the stomach that is chemically neutralized • However, if you take an OTC (Tagamet, Pepcid) that INHIBITS stomach acid production – instead of neutralization of acid, these compounds BIND to and INHIBIT receptors in the stomach wall responsible for producing acid! Receptors • Antibiotic therapy is another example of a drug that binds to a receptor that is not part of your body. Abx bind to portions of the bacterium that is living in the body which is causing illness. • Most Abx inhibit an enzyme inside the bacteria that causes the bacteria to either stop reproducing or to die from inhibition of a vital biochemical process Receptors – another example • As medical science has learned more about how drugs at, pharmacologists have discovered that the body is full of different types of receptors that respond to many different types of drugs. Some receptors are very selective and specific, while others lack such specificity and respond to several different types of drug molecules Pharmacologist discoveries • To date, receptors have been identified for the following common drugs, or neurotransmitters found in the body: • Narcotics (opioids) – Morphine • Benzodiazepines (Valium, Xanax) • Acetylcholine (nicotinic and muscarinic cholinergic receptors) found in the parasympathetic system (resting/digesting) • Dopamine, serotonin (sympathetic system) • Epinephrine (adrenalin) and NE (alpha and beta receptors) – found in the sympathetic system (fight/flight) of the CNS and many others…. Receptors – common drugs • Neurotransmitters are chemicals released from the END of ONE NEURON (nerve cell) which diffuse across the space between neurons called the synaptic cleft and stimulate an adjacent neuron to signal the transmission of information…. Neurotransmitters • Pharmacokinetics – what is it? – a branch of pharmacology which deals with determining the movement (kinetics) of drugs into and out of the body Pharmacokinetics • Absorption • Distribution • Metabolism • Excretion Four scientific or pharmacokinetic processes….. • Is the process by which a drug is made available to the fluids of distribution of the body (e.g., blood, plasma, serum, aqueous humor, lymph, etc.). • In the fasting state, most orally-administered drugs (PO) reach maximum or “peak” blood concentration within one to two hours • IV is the most rapid route of administration, then… • Intra-nasal • Inhalation • SL • IM • SC or SQ (in the above order) – route of administration…. Absorption • Dependent on (PO drugs) – and the subsequent appearance of the drug in the blood on the following factors: • Rate of disintegration and dissolution of the pill or capsule in the stomach or GI tract • Solubility of the drug (the more soluble, the faster absorption rate) • The molecular charge of the drug molecule (charged substances are soluble, but don’t pass through lipid (fat) soluble biologic membranes well) • Aqueous (water) solubility vs. lipid (fat) solubility • The presence or absence of food in the stomach (food delays the absorption of some drugs and enhances the absorption of others) Rate of Absorption - • The presence of any concomitant medication(s) that can interfere with GI motility (e.g., Reglan increase GI motility, Aluminum antacids slow motility, atropine or scopolamine used for ulcers or nausea also slow GI motility (anticholinergic) keeping some drugs in the stomach longer – slowing absorption rate; on the flip side: • Tagamet, Zantac and Prilosec (Pepcid-AC) DECREASE gastric acid production thereby INCREASING the rate of gastric emptying and increasing the rate of absorption.. Rate of Absorption – key factors • Once the drug has been absorbed from the stomach and/or intestines (GI tract) into the blood, it is circulated to some degree to all areas of the body to which there is blood flow…this process is distribution (the choo-choo so to speak) • Organs with high blood flow (brain, heart, liver, etc.) are the first to accumulate drugs, while connective tissue and lesser-perfused organs are last… Distribution • The pattern of distribution of drug molecules by different tissues after the chemical enters the circulatory system varies. Why? Because of differences in pH, lipid content, cell membrane function and other individual tissue factors, most drugs are NOT equally distributed in all parts of the body • E.g., ASA acidity influences a distribution patter that is different from that of an alkaline product such as amphetamine Distribution effects • Is the transformation of the drug molecule into a chemically related substance that is more easily excreted from the body (also know as: biotransformation, or detoxification) • Drug metabolism is the process by which the body breaks down and converts medication into active chemical substances. • Drugs can interact with other drugs, food and beverages. Interactions can lessen or magnify the desired therapeutic effect of a drug, or may cause unwanted or unexpected side effects Metabolism • The primary site of drug metabolism is the liver…plays a major role in digestion, detoxification, and elimination of substances from the body (ponder of this statement for moment…consider disease processes such as ES liver disease – what do you need to consider when administering drugs that are metabolized in the liver)? Metabolism – primary site • Enzymes in the liver are responsible for chemically changing drug components into substances known as metabolites • Metabolites are then bound to other substances for excretion through the lungs, or bodily fluids such as saliva, sweat, breast milk and urine, or through reabsorption by the intestines Metabolism • Can vary from individual to individual – and drug dosages that work quickly and effectively in one individual may not work well for another • Factors such as genetic disposition, environment, nutrition and age can influence drug metabolism • Infants and elderly patients may have a reduced capacity to metabolize certain drugs and can be at risk for drug toxicity Metabolic Rate • Therapeutic agents like antibiotics and drugs used for the treatment of high blood pressure, epilepsy (phenobarbital, Dilantin) pain (morphine, codeine), anxiety (valium Xanax) are also metabolized to chemically-related compounds called metabolites which are excreted in the urine… Metabolism • Diuretics (such as HCTZ) can reduce serum K+ and Na+ electrolyte levels when taken with digoxin and lithium respectively • MAOIs antidepressants can cause convulsions and other serious side effects when used with tricyclic antidepressants (nortriptyline), SSRIs or sympathomimetic drugs (amphetamines) • Antibiotics may reduce the efficiency or oral contraceptives Drugs that commonly interact with other meds: • Medications containing metals, such as antacids with aluminum additives and iron supplements can reduce the absorption of tetracycline's and fluoroquinolones • Drugs that inhibit liver enzyme function – thereby slowing metabolism include; ciprofloxacin, erythromycin, fluoxetine, paroxetine and ritonavir. The therapeutic effect of other medications taken with these drugs may be amplified – Coumadin should be used with GREAT caution in patients taking these drugs! Drugs that commonly interact with other meds: • Grapefruit juice inhibits metabolism of many meds; including: cyclosporines, felodipine, nifedipine, triazolam and midazolam (to name a few) • Foods and beverages with tyramines (red wine, malted beers, smoked foods, dried fruits and aged cheeses) can cause severe and dangerous elevation in blood pressure when taken with MAOI inhibitors (antidepressants – emsam; marplan; nardil; parnate) Foods and beverages / drug interactions • Dairy products (milk, cream) and products containing calcium can prevent the absorption of antibiotics such as tetracycline, doxycycline, and ciprofloxacin • Whole milk with Vitamin D can cause milk-alkali syndrome in patients taking aluminum hydroxide antacids • Caffeinated beverages can influence drug metabolism • Alcohol is a CNS depressant – should not be combined with other CNS depressants (antipsychotics, antihistamines) Foods and beverages / drug interactions • Is the process by which a drug is eliminated from the body – by various organs such as the kidney and lungs and found in many biological fluids like: bile, sweat, hair, breast milk, or tears. However, the most common is the urine (excretion of drug) • In order to determine the rate of excretion of any drug from the blood, one must first be certain that the entire drug in the patient’s GI tract has been absorbed (consider GI patients who’s absorption rate is impaired via their disease process…) Excretion • The amount of time required to eliminate half of the drug from the body is called the half-life • Generally, it takes six half-lives to rid the body of 98% of drug and 10 half-lives to completely eliminate the drug from the body • Using these mathematical relationships allows pharmacologists to determine how often a therapeutic drug should be administered to a patient or toxicologist to determine a time interval within which one would test positive for drugs of abuse Excretion • A medication will have a generic name and one or more trade names – the generic name usually signifies the medication's chemical derivation. The trade name is a name chosen by the pharmaceutical company for purposes of marketing. • Trade names usually begin with a capital letter and followed by a trademark • Generic names generally begin with a lower case letter Drug Nomenclature Generic Trade ibuprofen Motrin® acetaminophen Tylenol® benzoyl peroxide Oxy10® Examples • Drugs are classified into different groups according to their chemical characteristics, structure and how they are used to treat specific diseases • Example: Controlled versus Non-controlled; Noncontrolled med is not considered to be a depressant or a stimulant and is not considered addictive or with a potential for abuse (OTCs or prescription drug) Drug Classifications • Are divided into five schedules based on their potential for abuse and physical and psychological dependence Controlled Meds • Schedule I: drugs that currently do not have accepted medical use, have a high potential for abuse, and lack accepted safety measures for use (LSD, peyote, heroin) • Schedule II: drugs that have medical use and a high potential for abuse; may cause severe dependence (morphine, secobarbital, amphetamines (Ritalin), methadone) Controlled meds • Schedule III: drugs used in medical practice with less potential for abuse than Schedule II drugs; may cause moderate to low physical dependence or high-psychological dependence (T3s – Tylenol with codeine; stimulants, depressants, other classes – ketamine is another example) • Schedule IV: drugs that have medical use and lower abuse potential than CIII drugs; tend to cause limited physical or psychological dependence (diazepam) • Schedule V: drugs that have medical use and lower potential for abuse than CIV drugs – (cough syrups containing Codeine) Controlled Meds • Enable us to readily identify the similarities and differences among a large number of medications; one of the best ways to master pharmacology is to become familiar with medication classifications….let’s review some…. Drug Classifications Actions They bind to a-adrenergic receptors – leading to dilation of peripheral blood vessels; lowering peripheral resistance and BP Uses HTN, BPH, Raynaud’s – short/longacting agents –(Cardura, Minipress) Adverse reactions /side effects Hypotension, nasal congestion, tachycardia, diarrhea, N/V Contraindications MI, CAD, including angina Implications K+, Na+, carbon dioxide lab monitoring - daily #’s; intake/output data – orthostatic BP’s Alpha-Adrenergic Blockers Actions Contain magnesium, aluminum, calcium and a combination of these compounds. They slow down the rate of gastric emptying and neutralize gastric acidity Uses Gastritis, peptic ulcer, hiatal hernia and GERD (aluminum carbonate, calcium carbonate – tums) Adverse Reactions & Side Effects Constipation, diarrhea, flatus, abdominal distention, alkaluria Contraindications Allergy and sensitivity Implications Assess epigastric pain, GI symptoms and renal problems and electrolytes Antacids Actions Nitrates – dilate coronary arteries, decrease preload/afterload; CCB – dilate CA, decrease SA/AV node conduction; BB – decrease HR, thus decreasing oxygen use Uses Angina. CCBs, BBs – HTN and dysrhythmias (ol’s, nitro, verapamil) Adverse Reactions & Side Effect Postural Hypotension, fatigue, dysrhythmias, HTN, edema, dizziness Contraindications Increase ICP, cerebral hemorrhage and sensitivity Implications Monitor for SE / Orthostatic BP; assess for angina pain Antianginals Actions Inhibit acetylcholine (autonomic NS) Uses Many. Some decrease GI, urinary and biliary motility; GI secretions, decrease involuntary movement and relieve N/V; decrease secretions at EOL; increase HR in emergent situation; COPD (atropine, scopolamine) Adverse Reactions/Side Effects Dryness of mouth; paralytic ileus, constipation, urinary retention/hesitancy) dizziness and Ha Contraindications GI or urinary obstruction; narrowangle glaucoma, and myasthenia gravis Implications Monitor urinary and bowel function as well as vital signs; Anticholinergics Action Prevent clot formation Uses MI; PE; DVT; DIC; Afib; and HD patients (Coumadin, heparin) Adverse Reactions & Side Effects Hemorrhage, diarrhea, fever, rash and blood disorders (leukopenia, thrombocytopenia) Contraindications Bleeding disorders, such as hemophilia, and leukemia, ulcers, blood dyscrasias, nephritis, endocarditis and thrombocytopenia purpura Implications Observe for bleeding (black stools, ecchymosis); monitor hgb/hct; PT/INR; PTT; vital signs Anticoagulants Actions To prevent seizures Uses Prevent tonic-clonic seizures, psychomotor seizures, status epilepticus, petit mal and cortical focal seizures (Phenytoin, Diazepam) Adverse reactions & side effects Bone marrow suppression (can be lifethreatening) GI problems; CNS effects like confusion, ataxia and slurring of speech Contraindications Allergy or sensitivity to drug class Implications Monitor hepatic and renal function, blood, mental status, blood dyscrasias, and toxicity – especially StevensJohnson syndrome Anticonvulsants Actions MAOIs – inhibit MAO and thus increase epinephrine, NE, serotonin and dopamine; Tricyclic's - block the reuptake of serotonin and NE in the nerve endings, thus increasing the actions of both in the nerve Uses Depression, nocturnal enuresis in children; (Sertraline; amitriptyline; bupropion; lithium) Adverse Reactions & Side Effects Orthostatic hypotension; dry mouth; dizziness, drowsiness; urinary retention, HTN, renal failure and paralytic ileus Contraindications BPH; seizure disorders, renal, hepatic and cardiac disease Implications Monitor BPs; mental status; renal/hepatic function; extrapyramidal symptoms; urinary retention; withdrawal s/sx with abrupt cessation Antidepressants Actions Lowers blood sugar, K+ and P04; oral med stimulates B-cells of pancreas to release insulin Uses Diabetes and ketoacidosis; (Insulin, Glyburide) Adverse Reactions & Side Effects Hypoglycemia, hepatotoxicity, allergic responses Contraindications Oral agents are contraindicated for juvenile diabetes and ketoacidosis Implications Monitor CBGs; assess for hypoglycemia, rotate insulin injection sites and use human insulin when pork or beef sensitivity Anti-Diabetic Meds Actions Varying. Some decrease water content in stool, some slow GI peristalsis Uses Diarrhea; (bismuth, kaolin pectin; loperamide) Adverse Reactions & Side Effects Constipation, paralytic ileus, abdominal pain Contraindications Colitis Implications Used for short term therapy (48 hours or less) monitor electrolytes and bowel response Antidiarrheal Actions Class I: - decreases any disparity in the refractory period; increases duration of AP Class II: slows rate of SA node discharge and conduction through AV node; decreases HR – decreasing oxygen demand in myocardium Class III: increases effective refractory period and AP duration Class IV: decreases SA nod discharge; slows conduction through AV node; inhibits Ca++ across cell Uses Atrial and Ventricular arrhythmias (afib, PVCs and tachycardia, HTN, angina) Digoxin, procainamide, acebutolol, amiodarone Adverse Reactions and Side Effects Hypotension, bradycardia, pro-arrhythmic effects Contraindications Various – can be numerous Implications Monitor rate and rhythm, BP, K+ dependent edema, I/Os; eyesight, lung function; kidney function Antidysrhythmics Actions Decreases Na+, K+ and nutrients in the cell and increases cell permeability Uses Fungal infections such as cryptococcosis, aspergillsis, histoplasmosis, coccidiomycosis and candidiasis (Nystatin, Amphotericin B) Adverse Reactions & Side Effects Renal, liver damage and failure, gastroenteritis, hypoK+, anorexia, N/V Contraindications Sensitivity and bone marrow depression Implications For IV administration, use a filter, check for extravasation and protect from light (cover with foil). Monitor VS, I/O, weight, renal and hepatic function, HypoK+ and ototoxicity Antifungals Actions Antagonists of Histamine Uses Allergies, pruritus and rhinitis; decrease N/V; (Benadryl, Allegra, Claritin, Alavert, Tavist, Zyrtec, Chlor-trimeton); Adverse Reactions & Side Effects Drowsiness, Ha, urinary retention, blood dyscrasias, thickened bronchial secretions and GI effects Contraindications Sensitivity, asthma, PUD, narrow angle Glaucoma Implications Monitor urinary frequency, respiratory and cardiac status and for blood dyscrasias Antihistamines Actions ACEI – dilate arterial and venous system; suppression of RA I to RA II; CA Adrenergic: inhibits impulses in CNS (SNS); decrease in CO, BP and HR Peripherally Adrenergics: inhibits release of NE; decreasing sympathetic vasoconstriction Vasodilators: decrease BP, HR/CO – dilate smooth muscle of the arteries; BB/CCB/Diuretics – discussed later Uses HTN, HF, angina and some dysrhythmias Adverse Reactions & Side Effects Hypotension, tachycardia, bradycardia, N/V/Ha Contraindications Heart block, hypersensitivity Implications Edema, monitor renal function, and HF Antihypertensives Actions Inhibit the growth and/or replication of susceptible bacteria Uses Infection(s) – (PCN, Tetracycline) Adverse Reactions & Side Effects D/N/V, bone marrow depression and anaphylaxis Contraindications Hypersensitivity; most ppl allergic to PCNs are also allergic to cephalosporin's Implications Observe bowel pattern and urinary output. Monitor renal function, blood cultures and for signs of super infection and bleeding; along with WBCs Anti-Infectives Actions Alkylating agents – interfere with DNA; Antimetabolites – inhibit DNA synthesis Antibiotics: - inhibit RNA delay or inhibiting mitosis Hormones: - change the effects of androgens, estrogen, luteinizing hormone and FSH Uses Tumors, lymphoma, leukemia and Hodgkin’s disease (fluorouracil; cisplatin) Adverse Reactions & Side Effects Anemia, thrombocytopenia, leukopenia, N/V; hair loss, hepatotoxicity, cardiotoxicity Contraindications Sensitivity, liver and renal damage Implications Monitor CBC with diff; renal and liver function tests; I/O; observe for bleeding, jaundice, dependent edema, breaks in skin and mucosal inflammation, irritation, phlebitis with IV route Antineoplastics Actions Cholinergic-block acetylcholine receptors (blocks PSS) Uses Parkinson’s Disease (Levodopa) Adverse Reactions & Side Effects Involuntary movement, insomnia, N/V; orthostatic Hypotension; dry mouth; numbness and Ha Contraindications Sensitivity and narrow angle glaucoma Implications Monitor respirations, BP and changes in mentation Antiparkinson Agents Actions Block dopamine receptors in the brain that involves psychotic behavior Uses Schizophrenia, mania, paranoia, and anxiety; can be used for unrelieved hiccups, N/V and pedi behavioral problems and pre-op relaxation (haldol, lithium) Adverse Reactions & Side Effects Extrapyramidal symptoms (dystonia, EPS< akathisia, and tardive dyskinesia); dry mouth, photosensitivity, agranulocytosis, hypotension and life threatening cardiac problems and laryngospasm Contraindications CAD, severe HTN, depression, bone marrow depression; blood dyscrasias, parkinsonism, cerebral arteriosclerosis, narrow angle glaucoma and children less than 12; caution in elderly Implications Monitor CBC, LFT’s I/O; BP; dizziness; palpations, tachycardia; LOC, gait and sleep patterns Antipsychotics / Neuroleptic agents Actions Decreases the replication of the offending bacillus through the inhibition of RNA or DNA Uses Pulmonary TB (Rifampin, Isoniazid, Rifabutin) Adverse Reactions & Side Effects Anorexia, N/V; rash, renal, hepatic and ototoxic effects Contraindications Sensitivity, renal disease; caution with hepatic disease, pregnancy and lactation Implications Check renal and hepatic status and s/sx of anemia Antituberulars Actions Antitussives – suppression of the cough reflect; Expectorants – decrease in the viscosity of thick, tenacious secretions Uses Cough – bronchitis, TB, pneumonia, CF; COPD; (antitussives are used for non-productive coughs) – Guaifenesin, codeine) Adverse Reactions & Side Effects Dizziness, drowsiness and nausea Contraindications Iodine sensitivity, pregnancy, lactation and hypothyroidism; caution in elderly and asthma patients Antitussives and Expectorants Implications Monitor cough and sputum, increase fluid intake and humidification to thin secretions Actions Interferes with the DNA needed for viral replication Uses HIV, herpes, encephalitis, varicella zoster encephomyelitis, influenza (acyclovir, tamiflu) Adverse Reactions & Side Effects N/V/D/Ha, anorexia, vaginitis, renal failure and metabolic encephalopathy which could be fatal Contraindications Caution in pregnancy and lactation; renal and liver disease and dehydration Implications Assess renal and liver functions; observes for s/sx of infection and allergic reactions (itching, rash, urticaria); monitor for blood dysrasias Antivirals Actions Decrease impulse transmission to the cerebral cortex Uses Epilepsy, sedation, insomnia, anesthesia, (phenobarbital and secobarbital) Adverse Reactions & Side Effects Drowsiness, Nausea, blood dyscrasias and Steven-Johnson syndrome Contraindications Allergy, poor liver function, pregnancy (cat D). Caution in elderly Implications Monitor seizure control, BMP, LFTs; observe for toxicity – insomnia, hallucinations, hypotension, pulmonary constrictions, cold clammy skin, cyanosis of lips (circumoral) N/V delirium, weakness) Barbiturates Actions Decreases anxiety by potentiating gaminobutyric acid and other CNS inhibitory transmitters Uses Anxiety secondary to phobic disorders and other conditions, acute ETOH withdrawal and pre-op (Diazepam, Clonazepam) Adverse Reactions & Side Effects Physical dependence and abuse, dizziness, drowsiness, OHTN, and blurred vision Contraindications Narrow angle glaucoma, infants less than 6 months, lactation (diazepam) and liver disease (clonazepam); caution in elderly Implications Monitor OHTN; HR, LFT’s BMP and signs of dependency; administer with milk or food to prevent GI upset Benzodiazepines Actions Selective: block stimulation of B1 receptors (one heart) in the cardiac smooth muscle with chronotropic and inotropic effects; Non-selective: lowers BP (plasma renins are reduced) w/o reduction in HR or reflex tachycardia Uses HTN, angina and ventricular dysrhythmias (atenolol, metoprolol, propranolol,) Adverse Reactions & Side Effects Ohtn, N/V/D, bradycardia, blood dyscrasias, CHF and bronchospasm Contraindications Hblock, cardiogenic shock and HF; caution in elderly, COPD an asthma patients; CAD, renal and thyroid disease patients Implications Monitor VS; I/O, Daily #s; renal function, edema, apical and radial pulse Beta-Adrenergic Blockers – BB (ol’s) Actions Anticholinergics – inhibit the interaction of acetylcholine at receptor sites on bronchial smooth muscle Uses Asthma, bronchospasm, COPD, CheyneStokes respirations (albuterol, aminophylline) Adverse Reactions & Side Effects Dyspnea, bronchospasm, anxiety, tremors, throat irritation, N/V Contraindications Narrow angle glaucoma, severe cardiac disease, tachydysrhythmias and sensitivity; use caution with HTN, seizure disorders, pregnancy and lactation, hyperthyroidism and BPH Implications Assess for a therapeutic response (absence of dyspnea and/or wheezing) and patient/family education about use of inhaler Bronchodilators Actions Inhibits the flow of calcium ions across the cell membrane of cardiac and vascular smooth muscle, thus relaxing the coronary vascular smooth muscle, dilating the CA, slowing SA/AV node conduction, and dilating peripheral arteries Uses Angina, HTN, and dysrhythmias (verapamil, felodipine) Adverse Reactions & Side Effects Dysrhythmias, edema, fatigue, HA and drowsiness Contraindications SBP of less than 90 mmHg; Wolff-Parkinson White Syndrome; 2/3rd degree HB; SSS; and cardiogenic shock; HF may get worse in the presence of edema; caution with renal and hepatic disease Implications Monitor BP, HR, RR; administer at bedtime and before meals Calcium Channel Blockers Actions Cardiac output and cardiac contractility are enhanced by making more calcium available Uses HF and tachycardia (digitoxin, digoxin) Adverse Reactions & Side Effects Cardiac changes, hypotension, GI blurred vision, yellowish-green halos and Ha Contraindications Hypersensitivity, Vfib, Vtach and carotid sinus syndrome; caution with electrolytes imbalance; acute MI; severe respiratory disease, AV block, renal or liver disease, hypothyroid and the elderly Implications Assess VS, check apical rate for one full minute – if less 60 hold and notify physician; monitor BMP; I/O Cardiac Glycosides Actions These medications prevent the destruction of acetylcholine, thus increasing its concentration, which enhances the transmission of impulses Uses Myasthenia gravis, bladder distention, urinary distention, and post –op paralytic ileus (neostigmine, bethanechol) Adverse Reactions & Side Effects Bronchospasm, laryngospasm, respiratory depression, convulsion, paralysis, respiratory arrest, N/V/D Contraindications Renal or intestinal obstruction, cautious with children, lactation, bradycardia, hypotension, seizure disorders, bronchial asthma, coronary occlusion and hyperthyroidism Implications Monitor VS, I/O; assess for urinary retention, bradycardia, bronchospasm, hypotension, respiratory depression Cholinergics Actions Blocks the ANS acetylcholine Uses Prevention of surgical secretions, - (at EOL also) decrease motility of the urinary, biliary and GI tracts; reverses NM blockage; parkinsonism symptoms secondary to the use of neuroleptic medications (atropine, scopolamine) Adverse Reactions & Side Effects Constipation and dryness of the mouth Contraindications GI and GU obstruction, angle closure glaucoma, myasthenia gravis, and hypersensitivity; caution with elderly, BPH and tachycardia patients Implications Monitor urinary status; I/O – monitor dysuria, frequency or retention; observe constipation, LOC; administer with milk or food Cholinergic Blockers Actions Glucocorticoids – increase capillary permeability and suppress the movement of fibroblas and leukocytes, thereby decreasing inflammation Uses Glucocorticoids – decrease inflammation – some are used for adrenal insufficiency, allergies and cerebral edema (cortisone, dexamethasone, hydrocortisone, prednisone) Mineralocorticoids – adrenal insufficiency Adverse Reactions & Side Effects Insomnia, euphoria, behavioral changes, PUD, sodium and fluid retention, hypokalemia, hyperglycemia, and carbohydrate intolerance (metabolic reactions) Contraindications Fungal infections, amebiasis, hypersensitivity, and lactation. Caution in elderly, children and pregnant women, diabetes, seizures, PUD, glaucoma, HF, HTN, impaired renal function ,myasthenia gravis and ulcerative colitis Implications Give with food; monitor CBG, K+; Weight; I/O; plasma cortisol levels, adrenal insufficiency and for any signs of infection; mood changes, particular depression Corticosteroids Actions Thiazides and thiazide-like diuretics – slow reabsorption n the distal tubule, thus increasing the excretion of sodium and water; Loop diuretics – inhibit the reabsorption of Na+ and Chloride in the loop of Henle Carbonic anhydrase inhibitors – decrease the sodium-hydrogen ion exchange in the tubule, thus increasing sodium excretion Uses HTN with edema and HF (lasix, HCTZ, aldactone) Adverse Reactions & Side Effects HypoK+; hyperglycemia and hyperuricemia (mostly with thiazides) blood dyscrasias, aplastic anemia, volume depletion, and dehydration Contraindications Electrolyte imbalances, anuria, dehydration; caution in elderly and renal or hepatic patients Implications K+ supplement may be needed with loop diuretic; observe for signs of hypokalemia and metabolic alkalosis; given in am Diuretics Actions Inhibits histamine in the parietal cells, thereby inhibiting the secretion of gastric acid secretion Uses Gastric and duodenal ulcers, GERD; (cimetidine, ranitidine) Adverse Reactions & Side Effects Thrombocytopenia, neutropenia, aranulocytosis, aplastic anemia, confusion, diarrhea and Ha Contraindications Hypersensitivity, cautious in children less than 16 years of age, hepatic or renal disease, organic brain syndrome, lactation and pregnancy Implications Monitor I/O; creatinine, BUN and gastric pH; (maintain above 5); give slowly IV over 30 minutes to avoid bradycardia and administer oral with meals Histamine H2 Antagonists Actions Inhibits lymphocytes Uses Prevention of organ transplant rejection; cyclosporine, azathioprine) Adverse Reactions & Side Effects Proteinuria, renal failure, albuminuria, hematuria, hepatotoxicity, oral candida, gum hyperplasia, HA and tremors Contraindications Hypersensitivity; caution in severe hepatic or renal disease and pregnancy Implications Monitor LFTs and BMP, drug blood levels; observe for hepatotoxicity, which can include itching, light colored stools, jaundice and dark urine; administer with meals Immunosuppressant's Actions Used to treat and prevent constipation; bulk laxatives absorb water thus adding bulk to stool; Lubricants: increase water retention in stool Stimulants: speed up peristalsis Saline laxatives – pull water from intestines Osmotic – enhance peristalsis and increase distention Stool softeners – reduce surface tension of liquids within the bowel Uses Constipation, bowel prep; (psyllium, colace, mag citrate; mineral oil, bisacodyl) Adverse Reactions & Side Effects Cramping, D/N Contraindications Megacolon, abdominal pain, N/V, impaction, GI obstruction or perforation, gastric retention and colitis; Implications Monitor I/O, electrolytes; Laxatives Actions Inhibition of nerve impulse transmission Uses The facilitation of endotracheal intubation and skeletal muscle relaxation (surgery/general) (gallamine, pancuronium) Adverse Reactions & Side Effects Apnea, respiratory depression, bronchospasm, and bradycardia Contraindications Hypersensitivity; cautious use with collagen, thyroid and cardiac disease, lactation, pregnancy, children < 2; dehydration, electrolyte imbalances and myasthenia gravis Implications Monitor K+ and Mag+; VS q 15’ until recovery; I/O; IV doses may be given over 1-2 min NM blocking agents Actions Decreases prostaglandin synthesis Uses Mild to moderate pain, arthritis and dysmenorrhea (Ibuprofen, Naproxen) Adverse Reactions & Side Effects Blood dyscrasias, nephrotoxicity (oliguria, azotemia, hematuria and dysuria) abdominal pain, cholestasis hepatitis, anorexia, dizziness and drowsiness Contraindications Asthma, severe liver and/or renal disease, hypersensitivity. Caution in elderly, children, lactation, pregnancy and for patients with GI, cardiac and/or bleeding disorders Implications Monitor renal and hepatic function. Obtain baseline hearing and eye exams; toxicity may include: tinnitus and or blurred vision NSAIDs Actions Depression of the pain impulse transmission at the level of the spinal cord Uses Moderate to severe pain (Codeine, fentanyl, morphine, oxycodone) Adverse Reactions & Side Effects GI (constipation, n/v; anorexia, cramps); sedation, respiratory depression; circulatory depression and increased ICP Contraindications Upper airway obstruction, bronchial asthma, addiction, hypersensitivity. Caution with: renal, hepatic, respiratory and cardiac disease Implications Monitor RR; urinary/GI output; LOC; can be used as antiemetic for N/V; continue to monitor/assess for pain Opioid analgesics Actions Antipyretic (inhibits the heat regulation center in the hypothalamus), anti-inflammatory, analgesic (inhibits prostaglandin), Uses Mild to moderate pain, inflammation (arthritis), fever, and thromboembolic disorders (ASA, salsalate) Adverse Reactions & Side Effects Rash, GI symptoms, hepatotoxicity, blood dyscrasias, hearing problems (tinnitus) a sign of possible toxicity Contraindications Hypersensitivity; contraindicated with Vit K deficiency, GI bleed; bleeding disorders; children with Reye’s syndrome; caution: Hodgkin's; hepatic/renal failure, anemia Implications Monitor renal/hepatic function; observe for hepatotoxicity (clay colored stools, dark urine, diarrhea, yellow sclera, itching, fever, abd. Pain tinnitus Salicylates Actions Convert plasminogen into plasmin to break down the fibrin of clots Uses PE, DV and arterial thrombosis; MI, AV cannula occlusion (Streptokinase, urokinase) Adverse Reactions & Side Effects Anaphylaxis, GI, GU, IC retroperitoneal bleeding; most common are decreased HCT, urticaria, Ha and N Contraindications Hypersensitivity; CNS neoplasms, bleeding, renal or hepatic disease, HTN, COPD, subacute bacterial endocarditis, rheumatic VHD, cerebral embolism or thrombosis or hemorrhage and recent surgery Implications Monitor VS and LOC; monitor bleeding (temp >104); arrhythmias, retro bleed; allergic response; ecchymosis, hematuria, hematemesis, epistaxis; not effective if thrombi are more than 1 wk old. Use 0.8 mm filter with IV administration Thrombolytics Actions Increase metabolism, C/O, blood volume, 02 consumption and RR Uses Thyroid replacement (thyroid, levothyroxine) Adverse Reactions & Side Effects Palpitations, tachycardia, insomnia, tremors, angina, #loss, dysrhythmias, thyroid storm Contraindications MI, adrenal insufficiency and thyrotoxicosis; caution in elderly, pregnant and lactating moms; DM, HTN, angina and cardiac disease Implications Administer at same time every day; monitor BP; I/O; #; cardiac status, irritability, excitability and nervousness Thyroid medications Actions Various – decreases vascular resistance and increases blood flow Uses HTN, angina, intermittent claudication, vasospasm, arteriosclerosis Imdur, Ismo (isosorbide mononitrate), Hydralazine, Isosorbide Dinitrate (SR); minoxidil; Nipride, Nitro-bid Adverse Reactions & Side Effects Hypotension, HTN, changes in EKG, Nausea, Ha Contraindications Tachycardia, acute MI, thyrotoxicosis; PUD, uncompensated heart disease Implications Administer with meals to reduce GI s/sx; monitor bleeding times and cardiac status Vasodilators • The topic of pharmacology is an important one for all involved in the filed of healthcare. Medications have great power to help patients, but can also harm them. Having an understanding of the basics of will allow clinicians to better serve their patients SUMMARY