The term p h a rm a c o l o g y

Practical Review of Pharm a c o l o g y C o n c e p t s Sue M. Janda Nancy L. Fagan The term p h a rm a c o l o g y is derived from the G reek words pharmakon, meaning dru g s, and logos, meaning science. P h a rmacology dates back to ancient times when man used plants and roots to treat ailments. In more recent times, the United States Congress has passed re g u- lations that re q u i re drug manuf a c t u rers to study and pro v e d rugs are safe and eff e c t i v e b e f o re being approved, prescribed, and sold to the public. Even with these studies, no d rugs are perfectly safe. Although all drugs produce diff e rent side effects, the objective of drug therapy is to pro v i d e maximum benefits with minimal h a rm. Pharmacology concepts a re used routinely in nursing practice (see Table 1). These concepts may be as simple as dru g names and side effects, or as complex as pharmacokinetics or p h a rmacodynamics. This art i c l e Sue M. J a n d a, P h a r m D, FA S H P, is a Staff P h a rmacist, Alegent Health Immanu e l Medical Center, Omaha, NE, and an A d j u n c t i ve Faculty Member, Department of C h e m i s t ry, Midland Lutheran College, Fremont, NE. N a n cy L. Fag a n, P h a r m D, is an Assistant P r o fessor of Pharmacy Pra c t i c e, D e - p a rtment of Pharmacy Pra c t i c e, Creighton U n i ve r s i t y, Omaha, NE. N o t e : The authors reported no actual or potential conflict of interest in relation to this c o n t i nuing nursing education art i c l e. N o t e : O b j e c t i ves and CNE Evaluation Fo rm appear on page 21. Pharmacology concepts are used ro u t i n e ly in nu rsing practice.t h e s e concepts may be as simple as drug names and side effe c t s, or as c o m p l ex as pharmacokinetics or pharmacody n a m i c s. All play major roles in drug efficacy and safe t y. A practical rev i ew of pharmacology, i n cluding pharmacokinetic and pharmacodynamic concepts, will be p r e s e n t e d. O b j e c t i v e s 2010 Society of Urologic Nurses and Associates U rologic Nurs i n g, p p. 1 5-2 1. Key Wo rd s : Pharmacology, adverse effects, pharmacokinetics, pharmacodynamics, therapeutic index. 1. Explain the four phases of pharmacokinetics. 2. Discuss the various ways a drug can be absorbed into the body. 3. Describe pharmacodynamics. 4. Explain how patients can respond differently to drugs. will provide a practical review of p h a rmacokinetic and pharm a c o- dynamic concepts. P h a r m a c o k i n e t i c s Pharmacokinetic concepts come into play once a drug enters the body. They include the phases of absorption, distribution, metabolism, and excretion (Lilley, H a rrington, & Snyder, 2007). Absorption Absorption is an import a n t phase of pharmacokinetics and includes three aspects: 1) ro u t e s of administration, 2) methods of absorption, and 3) factors that a ffect the absorption pro c e s s (Lilley et al., 2007). Routes of administration can be divided into three categories: enteral, parenteral, and other (non-enteral or p a renteral) routes. The enteral route includes any route using the gastrointestinal tract oral, sublingual, buccal, and re c t a l. The parenteral route entails intravenous, intramuscular, and subcutaneous administrations. The other route consists of inhalation, topical, transdermal, intranasal, intrathecal, intraventricular, and ophthalmic (Lilley et al., 2007). The three most common methods of absorption are passive absorption, active absorption, and pinocytosis. Passive absorption is also known as passive or simple diffusion. It is dependent on a concentration gradient and is UROLOGIC NURSING / January-February 2010 / Volume 30 Number 1 15

Ta ble 1. Definitions of Pharmacology Concepts A b s o rp t i o n A g o n i s t Te r m D e f i n i t i o n The uptake of substance by a tissue, such as nu t ri e n t s, though the wall of the gastrointestinal t ra c t. A drug or other chemical that can combine with a receptor on a cell to produce a phy s i o l o g i c reaction typical of a naturally occurring substance. A n t a g o n i s t A drug that counteracts the effect of another dru g. B i o ava i l a b i l i t y C l e a ra n c e Creatinine cleara n c e E f fe c t i ve dose (ED50) F i r s t - Pass G l o m e rular filtra t i o n rate (GFR) The fraction of an administered dose that reaches the systemic circulation. A measure of how well a patient can metabolize or eliminate a drug per unit time. A measure of the kidney s ability to eliminate creatinine from the body. The dose required to produce a specific therapeutic response in 50% of the patients. D rug removed from the blood or plasma fo l l owing absorption from the gastrointestinal tra c t b e fore reaching the systemic circulation. The volume of water filtered out of the plasma though glomerular capillary walls into Bow m a n s capsules per unit of time. H a l f - l i fe The time required for the plasma concentration to be reduced to one-half of the original va l u e. Lethal dose (LD50) A dose that will produce a lethal toxicity in 50% of studied gr o u p. Data obtained from T D 5 0. Pa rtial agonist P h a rm a c o d y n a m i c s P h a rm a c o k i n e t i c s A drug that produces a we a ker or less efficient response than an agonist. The study of the biochemical and physiological interactions of drugs at their sites of activity. The study of the absorption, distri bution, metabolism, and excretion of a drug, and its metabolites in the body. P h a rm a c o l o g y The science of dru g s, including their composition, uses, and effe c t s. P r o d ru g R e c e p t o r Steady state An inactive drug dosage fo rm that is conve rted to an active metabolite by va rious biochemical reactions once it is inside the body. A molecular structure or site on the surface or interior of a cell that binds with substances, such as horm o n e s, antigens, dru g s, or neurotra n s m i t t e r s. Rate of drug administration is equal to the rate of drug elimination. Toxicity dose (TD50) A dose that will produce a given toxicity in 50% of the studied gr o u p. T h e rapeutic class T h e rapeutic index Volume of distri bu t i o n A group of drugs with similar mechanism of actions that treat the same disease state. The ratio of the dru g s LD50 to its ED50 and measures drug safety margins. The apparent volume required to account for all the drug in the body in the same concentra t i o n as in the sample from the plasma. S o u rc e s : D i c t i o n a ry.com, 2010a, 2010b, 2010c; W i n t e r, 2004. the most important mechanism for drug absorption. In simple d i ffusion, particles move from an a rea of high concentration to an a rea of low concentration. There is no energy expenditure during this process, and drugs must be small, lipid or fat soluble, and non-ionized (no positive or negative charge) to cross the membranes. An acidic enviro n m e n t, such as the stomach, favors nonionization of weak acids, such as aspirin. There f o re, aspirin is m o re efficiently absorbed in the stomach than in the intestine. In contrast, the intestine is a basic e n v i ron ment and would favor non-ionization of weak bases, such as diazepam, which is more e fficiently absorbed in the intestine than in the stomach. The second method of absorption is active absorption, also known as active transport. Since this method re q u i res energ y, it is the opposite of passive diff u s i o n, which means it moves part i c l e s f rom an area of low concentration to an area of high concentration. The third method is called pinocytosis. This process allows cells to carry the drug acro s s their membrane by engulfing the d rug particles (Adams, Holland, & Bostwick, 2008; Kee, Hayes, & McCuistion, 2009). Multiple factors affect absorption, including rate of dissolution, blood flow, and contact time. The rate of dissolution determines the rate of absorption. If the drug dis- 16 UROLOGIC NURSING / January-February 2010 / Volume 30 Number 1

solves quickly, it will be absorbed, and the e ffects will be appare n t in a short period of time. With a slow-dissolving drug, the dru g must move from the stomach into the intestine, and the effects may not be seen for a longer period of time (Adams & Koch, 2010). This is a key concept with immediate or sustained release products, such as tolterodine (Detrol / Detrol LA ) or oxybutynin ( D i t ro p a n / D i t ropan XL ), often used for an overactive bladder. Blood flow impacts the rate of absorption. If an area has a high blood flow, there may be i n c reased absorption from that site. The intestine has more blood flow than the stomach; there f o re, m o re absorption may occur. C o n v e r s e l y, shock reduces blood flow to cutaneous tissue, and d rug absorption may be dec reased in that area (Adams & Koch, 2010). If a patient uses a d rug in a patch form, such as oxybutynin (Oxytro l ) or fentanyl ( D u r a g e s i c ), and absorption inc reases, some side effects of toxicity may be seen. However, if blood flow is decreased, the medications may not work as well on these patients. Using higher doses or switching to another form of the medication may be needed to optimize the desired effect. Contact time also aff e c t s absorption. If a drug is not in contact with absorption sites for a specific period of time, the dru g will not be completely absorbed. For example, diarrhea occurs because the decreased transit time in the gastrointestinal tract can affect the absorption of dru g s in the body. Dru g - d rug interactions and drug-food interactions may increase or decrease absorption of a drug (Sloan, 1992). One d rug may bind or alter the pro p e r- ties of another drug. Specific d rugs can react with a number of d rugs, food, or alcohol, and can be a ffected by various diseases and conditions (Anastasio, Cornell, & M e n s c e r, 1997; Kirk, 1995; Sloan, 1992; Ya m reudeewong, Henann, Fazio, Lower, & Cassidy, 1995). The bioavailability of a dru g can be altered by drug form, metabolism, surface area, and food. If a drug is administere d i n t r a v e n o u s l y, it has a bioavailability of 100% because the dru g is injected directly into a vein, and the body absorbs the entire d rug. However, a drug administ e red orally has a bioavailability of less than 100% for two re a- sons: 1) absorption is reduced, or 2) the drug is absorbed by the intestine, transported by the portal vein to the liver, and is metabolized before reaching the systemic circulation. Since this d e c reases the amount of dru g available to the systemic circ u l a- tion, it is known as the first-pass e ffect. Surface area is a principle element because drugs are absorbed slower in the stomach, which has a smaller surface are a. C o n v e r s e l y, drugs are absorbed faster in the intestine, which has a larger surface area. Some dru g s a re absorbed faster when taken with food, whereas other dru g s may absorb better if taken on an empty stomach (Kee et al., 2009). After drugs are absorbed into the bloodstream, they are distributed or transported through the b o d y. Drugs are distributed into the plasma, extracellular fluid, total body water, and the bloodbrain barr i e r. Drugs bound to plasma proteins, most commonly bound to albumin, are known as bound drugs, which are not pharmacologically active. Drugs that a re not bound are known as fre e d rugs, which are active and able to produce a pharm a c o l o g i c a l response. This is an import a n t consideration in patients with hypoalbuminemia. If a drug is highly protein bound and a patient has low albumin levels, m o re free drug would be available to the body, and the patient may experience toxic effects (Kee et al., 2009). Distribution I n i t i a l l y, drugs are distributed to the highest areas of blood f l o w, such as the heart, liver, kidn e y, and brain. Drugs are then distributed to areas with lower blood flow, such as muscles, skin, and fat. In these low-flow a reas, it is difficult to obtain high d rug concentrations, so diff e re n t routes of administration may be needed. Some areas, such as bone, have a very poor blood supply and are difficult to obtain adequate drug concentrations. The blood-brain barrier is a barr i- er that inhibits many chemicals and drugs from exiting the blood. Most medications do not easily c ross this barr i e r, making infections difficult to treat. With certain infections, such as meningitis, the blood-brain barrier becomes more permeable when inflamed and infections are more easily treated (Adams & Koch, 2010). The volume of distribution is a term used to quantify the distribution of a medication between plasma and the rest of the body after oral or parenteral doses. A small volume of distribution and high blood concentration usually occur with highly water- s o l u b l e d rugs. The high water content allows the drug to stay within the blood compartment. Wa t e r- s o l u- ble drugs that are highly pro t e i n bound are more strongly bound to proteins and are less likely to be absorbed into tissues, and thus, usually concentrated in the blood compartment. Atenolol ( Te n o rm i n ) is an example of a w a t e r-soluble drug. Conversely, a l a rge volume of distribution and low blood concentration are seen with fat-soluble drugs. Fat-soluble drugs, such as diazepam ( Va l i u m ), are usually poorly bound to protein but are easily absorbed into tissue and distributed throughout the body. Because of this, they may be reabsorbed into the circ u l a t i o n f rom tissue (Adams & Koch, 2010). Metabolism Metabolism is primarily associated with termination of dru g action. Metabolites often exhibit UROLOGIC NURSING / January-February 2010 / Volume 30 Number 1 17

lower pharmacologic activity and a re more water soluble, and theref o re, are more easily excreted (Kee et al., 2009). Pro - d rugs have no pharmacological activity and must be metabolized to become active. Clopidogrel (Plavix ), an antiplatelet drug used for coron a ry art e ry disease, peripheral vascular disease, and c e re b ro v a s- cular disease, is an example of a p ro - d rug. It undergoes rapid h y d rolysis to its active form by the cytochrome P450 system (Savi et al., 1994). The primary site of metabolism for drugs is the liver. The rate of metabolism is dependent on the blood flow. Other sites of metabolism include skin, lung, kidneys, and gastrointestinal tract. The most common dru g metabolism action is perf o rm e d by a large class of enzymes called m i c rosomal enzymes, also known as the Cytochrome P-450 enzyme system (Adams & Koch, 2010). The metabolism capabilities of the liver can vary from patient to patient. Factors that can alter metabolism include genetics, diseases, and concurrent use of other d ru g s. E x c retion Routes of drug excre t i o n include urine, bile, feces, expire d a i r, sweat, tears, saliva, and b reast milk. Renal excretion of d rugs is usually thro u g h g l o m e rular filtration, pro x i m a l tubular secretion, and distal tubular reabsorption (Lilley et al., 2007). Urinary excretion is the primary route of excretion. E x c retion can be affected by altering urinary ph. Acidification of urine increases the excretion of weak bases, such as diazepam. Alkaline urine can i n c rease the e x c retion of weak acids, such as aspirin. This is important especially in cases of overdose of these medications (Kee et al., 2009 ). The elimination half-life (t1/2) is a pharmacokinetic term that describes a dru g s duration of action. Drugs may have a half-life Figure 1. Estimated Creatinine Clearance Rate Using Cock c roft-gault Formu l a A commonly used marker for estimate of creatinine clearance is the Cock c r o f t - Gault Fo rmula, which estimates GFR. It is named after the scientists who first p u blished the fo rmula, and it employs serum creatinine measurements and a p a t i e n t s weight in kilograms to predict the creatinine cleara n c e. The fo rmula, as o riginally published, is: e C C r = (140) Age) x Mass (in kilograms) x [0.85 if Fe m a l e ] 72 x Serum Creatinine (in mg/dl) This fo rmula expects weight to be measured in kilograms and creatinine to be measured in mg/dl, as is standard in the U. S.The resulting value is multiplied by a constant of 0.85 if the patient is fe m a l e ; a value of 1 is used if the patient is m a l e. This fo rmula is useful because the calculations are simple and can often be perfo rmed without the aid of a calculator. Another va riation of the fo rmula simplifies the calculation by using a Lean Body Weight calculation that accounts for the constant number of 0.85 for women or 1 for men as fo l l ows : Creatinine Clearance (CrCl) = (140 Age) x Lean body Weight (LBW)* 72 x Serum Creatinine (Scr) (in mg/dl) *LBW (males) = 50 kg + (2.3 x eve ry inch over 5 fe e t ) ; LBW (females) = 45 kg + (2.3 x eve ry inch over 5 fe e t ). S o u rc e : W i n t e r, 2004. of minutes, hours, or days. The longer the half-life, the longer it takes for a drug to be excreted. It usually takes four to five half-lives for a drug to be at steady state. T h e re f o re, if a drug is ingested and the half-life is 2 hours, then in about 10 hours the drug will be out of the body s system (Adams & Koch, 2010; Kee et al., 2009). Clearance depends on blood flow and the ability of the org a n to remove the drug. Total body clearance is the sum of all the clearances in the body. This includes hepatic clearance, re n a l clearance, pulmonary clearance, and other organ clearances ( Wi n t e r, 2004). Renal disease can aff e c t g l o m e rular filtration rate (GFR), which may reduce the amount of d rug that is excreted by the kidney and could produce toxic e ffects. Creatinine clearance is used to evaluate renal function in milliliters per minute and can be calculated by many equations, the most common being the C o c k c roft-gault equation (see F i g u re 1) (Wi n t e r, 2004). Side Effects/Adverse Effects Side effects are types of adverse effects that are predictable and may occur even at therapeutic doses. An adverse e ffect, however, is an undesirable and potentially harmful action caused by the administration of medications. The number of d rugs a patient is taking incre a s- es the chance of an adverse eff e c t or drug interaction. This risk is estimated to be 6% when two medications are taken, 50% with five medications, and almost 100% with eight or more concurrent medications (Adams & Koch, 2010; Te rrie, 2004). Pharmacodynamics While pharmacokinetics relates to how the body changes the d rug, pharmacodynamics refers to how a drug changes the body. Patients can respond very diff e r- ently to drugs. This can be shown on a frequency distribution curv e, which is a graphic re p re s e n t a t i o n of patients response to a dru g action at diff e rent doses and usu- 18 UROLOGIC NURSING / January-February 2010 / Volume 30 Number 1

ally looks like a bell curve. The median effective dose (ED50) is in the middle of the distribution c u rve and reflects the dose re q u i red to produce a specific therapeutic response in 50% of the patients. Studies from animal data provide information to d e t e rmine the median lethal dose (LD50). Since the median lethal dose (LD50) cannot be determined experimentally in humans, a median toxicity dose (TD50) is of value for clinical practice. The TD50 is a dose that will produce a given toxicity in 50% of the studied group and is extrapolated from animal data and adverse drug effects that are re c o rded during the clinical trials. By using the median eff e c t i v e dose and the median lethal dose, the therapeutic index can be d e t e rmined. With the therapeutic index, the higher the safety margin, the safer the drug. A dru g with a low therapeutic index is associated with a narrow safety m a rgin, whereby a drug with a high therapeutic index is associated with a large safety marg i n. T h e re f o re, if a small medication e rror would occur, the consequences from the drug with a n a rrow safety margin could be toxic or lethal (Adams & Koch, 2 0 1 0 ). Plasma levels must be monit o red in drugs that have narro w safety margins. The concentration is measured usually at two points by obtaining peak and t rough blood levels. The peak level is the highest plasma concentration at a specific time, w h e reas the trough level is the lowest plasma concentration and m e a s u res the rate at which the d rug is excreted (Kee et al., 2009). An example is gentamicin, an aminoglycoside antibiotic that may be used to treat urinary tract infections or urosepsis. Obtaining peak and trough levels are necessary to determine therap e u t i c response and prevent toxicity. T h e re are four ways to comp a re medications within a therapeutic class: potency, eff i c a c y, s a f e t y, and cost. A more potent d rug will produce an effect at a lower dose. The efficacy is the magnitude of maximal re s p o n s e that can be produced from a d rug. If two drugs are compare d, the drug with the highest maximal response is more eff i c a c i o u s (Adams & Koch, 2010). Safety would be determined based on side effects or toxicity. Cost is an i m p o rtant aspect; however, it is not the only issue when comparing medications in diff e re n t classes. D rugs produce their actions by activating or inhibiting re c e p- tors. Several possibilities may occur when a drug binds to a re c e p t o r, which includes agonists, partial agonists, and antagonists. An agonist activates a receptor and produces the same type of response as the endogenous substance. Compared with an agonist, a partial agonist produces a weaker or less eff i c i e n t response. An antagonist competes with agonists for re c e p t o r binding sites (Adams & Koch, 2 0 1 0 ). D rug interactions can occur e v e ry day. Individual drugs may interact with other drugs, food, or laboratory tests. The occurrence of a drug interaction is m o re likely with polypharm a c y. D rug interactions can either i n c rease or decrease the actions of one or both of the involved d rugs, which can either be beneficial or harmful (Adams & Koch, 2 0 1 0 ). D rug interactions can be categorized as additive, synerg i s t i c, antagonistic, and incompatibilit y. Additive effects can occur when two drugs with similar actions are given together and a combined summation re s p o n s e occurs (for example, a diure t i c and a beta blocker each dru g d e c reases blood pre s s u re, but t o g e t h e r, they decrease blood p re s s u re to a greater degre e ). S y n e rgistic effect is when the e ffect of two drugs is greater than would be expected from adding the two individual drug re s p o n s- es. For example, Bactrim c o m- bines trimethoprim and sulfamethoxazole. Together they work better against bacteria than either one by itself. An antagonistic effect is caused when adding a second drug results in a diminished response and can cancel out the effects of the first d rug. This effect is seen fre q u e n t- ly when a narcotic, such as morphine, is given, and the patient has re s p i r a t o ry depre s s i o n. Naloxone (Narc a n ) is given to antagonize or block the effects of morphine, thereby restoring re s- pirations. Incompatibility usually involves parenteral drugs, and it occurs when two pare n t e r a l d rugs or solutions are mixed t o g e t h e r. The result is a chemical or physical reaction. The combination of the two drugs usually forms a precipitate, haziness c o l o r, or a temperature change occurs (Lilley et al., 2007) as in intravenous phenytoin (Dilantin ) and Dextrose 5% in Water (D5W). Phenytoin will usually pre c i p i t a t e out when mixed in D5W. C o n c l u s i o n P h a rmacokinetics and pharmacodynamics play a major ro l e in drug efficacy and safety. As each individual s response to d rug therapy may be diff e re n t, these two concepts can have a significant impact on patient outcomes. Nurses and health care p roviders should be aware of the p h a rmacokinetic and pharm a c o- dynamic pro p e rties of the dru g s they administer. Absorption, distribution, metabolism, and elimination of drugs are all import a n t factors that define the body s reactions to drugs once they enter the body and the impact of the drug on the body itself. Equally important is the mechanism by which the drug works, and the relationship between the d rug concentration and the b o d y s response. Knowledge of side effects, adverse drug re a c- tions, and monitoring parameters for drugs being administered are UROLOGIC NURSING / January-February 2010 / Volume 30 Number 1 19

c rucial elements of the clinical practice of nursing. These factors can be used to ultimately help assess the therapeutic outcome of d rug therapy. Utilization of these concepts can assist health care p roviders meet the objective of d rug therapy, which is to pro v i d e maximum benefits with minimal h a rm. R e f e re n c e s Adams, M.P., Holland, L.N., & Bostwick, P.M. (2008). P h a rmacology for nurs - es: A pathophysiologic appro a c h (2nd ed.). Upper Saddle River. NJ: P e a r s o n. Adams, M.P., & Koch, R.W. (2010). P h a rmacology connections to nurs - ing practice (1st ed.). Upper Saddle R i v e r, NJ: Pearson. Anastasio, G.D., Cornell, K.O., & Menscer D. (1997). Drug interactions: Keeping it straight. American Family Physican, 56(3), 883-888,891-894. D i c t i o n a ry.com. (2010a). Agonist. R e t r i e v e d J a n u a ry 7, 2010, from http:// d i c t i o n a ry. re f e re n c e. c o m / b ro w s e / a g o n i s t Dictionary.com. (2010b). Antagonist. Retrieved January 7, 2010, from h t t p ://d i c t i o n a ry. re f e re n c e. c o m / b ro w s e / a n t a g o n i s t D i c t i o n a ry.com. (2010c). G l o m e rular fil - tration rate. Retrieved January 7, 2010, from http://dictionary. re f e r- e n c e. c o m / b ro w s e / g l o m e ru l a rf i l t r a- t i o n r a t e L i l l e y, L.L., Harrington, S., & Snyder, J.S. (2007). P h a rmacology and the nurs - ing process (5th ed.). St. Louis, MO: M o s b y. Kee, J.L., Hayes, E.R., & McCuistion, L.E. (2009). P h a rmacology: A nursing p rocess appro a c h (6th ed.). St.Louis, MO: Saunders Elsevier. Kirk, J.K. (1995). Significant dru g - n u t r i- ent interactions. American Family Physician, 51(5), 1175-1182, 1185. Savi, P., Combalbert, J., Gaich, C., Rouchon, M.C., Maffrand, J.P., B e rg e r, Y., & Herbert, J.M. (1994). The antiaggregating activity is due to U rologic Nursing Editorial Board Statements of Discl o s u r e a metabolic activation by the hepatic cytochrome P450-1A. T h ro m b o s i s Haemostasis, 72(2), 313-317. Sloan, R.W. (1992). Principles of drug therapy in geriatric patients. A m e r i c a n Family Physician, 45(6), 2709-2718. Te rrie, Y.C. (2004). Understanding and managing polypharmacy in the elde r l y. P h a rma cy Times, 12, 9094. Retrieved from http://www. p h a rm a- c y t i m e s. c o m / i s s u e / p h a r m a - cy/2004/2004-12/2004-12-9094 Wi n t e r, M.E. (2004). Basic clinical phar - m a c o k i n e t i c s, (4th ed.). Philadelphia: Lippincott, Williams & Wi l k i n s. Ya m reudeewong, W., Henann, N.E., Fazio, A., Lower, D.L., & Cassidy T.G. (1995). Drug-food interactions in clinical practice. J o u rnal of Family Practice, 40(4), 376-384. In accordance with ANCC-COA gove rning rules Urologic Nursing E d i t o rial Board statements of disclosure are published with each CNE offe ri n g. The statements of disclosure fo r this offe ring are published below. K aye K. G a i n e s, M S, A R N P, C U N P, disclosed that she is on the Speake r s Bureau fo r P f i ze r, Inc., and Nova rtis Oncology. Susanne A. Q u a l l i ch, A N P - B C, N P - C, C U N P, disclosed that she is on the Consultants Bureau for Coloplast. All other U rologic Nurs i n g E d i t o rial Board members reported no actual or potential conflict of interest in relation to this continuing nursing education art i c l e. 20 UROLOGIC NURSING / January-February 2010 / Volume 30 Number 1