3NephronThe microscopic filtration unit of the kidney, consisting the glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct, which empties urine into the ureters.
4Glomerular Filtration Rate GFRIs a laboratory value the serves as a gauge of how well the kidneys are functioning as filters.180 liters of blood filtered through kidneys per day.
5Diuretic DrugsAll major classifications developed between 1950 and 1970 and are the most commonly prescribed drugs in the world.
6Diuretic DrugsClassified according to site of action
7Classifications of Diuretics Carbonic Anhydrase (Diamox): acts on the nephronsLoop diuretics (Lasix): acts on the loop of HenleOsmotic diuretics (Mannitol): works in the kidney on the glomerular filtrationPotassium sparing (Spiraldactone): works in the distal tubulesThiazides (Diuril): works in distal tubules
81. Carbonic Anhydrase Inhibitors Action: inhibit the action of the enzyme carbonic anhydrase.Site of action: nephronsIndications: glaucoma, edema, epilepsy, and high altitude sickness.
10Adverse effects Drowsiness Anorexia Paresthesias Hematuria (blood in urine)Melena (blood in stool)
11Interactions Increase in digoxin toxicity in clients taking digoxin. Corticosteroids may cause hypokalemia.Use with hypoglycemic drugs in diabetic type 2
12Acetazolamine Trade name: Diamox Classification: carbonic anhyrase inhibitorCaution: check with patient regarding drug allergy to sulfonamides or significant liver or renal dysfunction.
13Dosing Oral dosage for adults is 250 to 375 mg / day. Oral dosing for pediatric patient is 5 mg / kg /day.
142. Loop Diuretics Potent diuretics The drugs act primarily along the thick ascending limb of the loop of Henle, blocking chloride and sodium resorption.Also activate renal prostaglandins which results in dilation of blood vessels in kidneys and lungs and rest of body.
15Loop Diuretics Used when rapid diuresis is needed. Onset of action is1 hour and duration is 1-2 hours.Usually given in a single daily dose
16Major Side Effect Electrolyte imbalance Especially sodium and potassiumNurse alert: always check serum potassium and sodium levels before administering.
17Good Effects of Loop Diuretics Reduces blood pressureReduces pulmonary vascular resistanceReduces systemic vascular resistanceReduces central venous pressureReduces left ventricular end-diastolic pressure.
18ContraindicationsDrug allergyAllergy to sulfonamides
19Furosemide Trade name: Lasix Therapeutic classification: diuretic Pharmacologic classification: loop diureticPrimary use: pulmonary edema and edema associated with heart failure, liver disease and nephrotic syndrome.Used in treatment of hypertension caused by heart failure.
20Lasix DosingAdult: IV 0.5 to 1 mg / kg / dose (maximum 200 mg / day.
21Drug calculation problem Client weighs 170 poundsConvert pounds to kilograms _________Safe range of drug _______ to _______Physician order: 56 mg of Lasix IV STAT
22Drug calculation problem Lasix is provided as 10 mg / mLHow much would you need to draw up to give the 56 mg?
233. Osmotic DiureticsAction: increases the osmotic pressure of the glomerular filtrate inhibiting the reabsorption of water and electrolytes.
24When Used? Oliguric phase of acute renal failure. Increased intracranial or intraocular pressure.
27Dosing Adult dosing: 500 mg / kg (Given in intravenous solution) Onset 30 to 60 minutesPeak 1 hourDuration 6-8 hours
28Nursing Assessment Monitor vital signs Urine output Signs and symptoms of dehydrationDecreased skin turgorFeverDry skin and mucous membranesLow urine output
294. Potassium Sparing Diuretics Also called aldosterone-inhibiting diuretics because they block the aldosterone receptors.This causes sodium and water to be excreted and potassium to be retained.
30Potassium Sparing Diuretics Action: drugs work in the collecting ducts and distal convoluted tubules, where they interfere with sodium-potassium exchange.
31IndicationsUsed with other agents to treat edema or hypertension
32Contraindications and Precautions Use with caution in geriatric or debilitated patients or patients with diabetes mellitus (increased risk of hyperkalemia).Renal insufficiency (BUN >30History of gout or kidney stones
35AldactoneOnset: unknownPeak: 2-3 daysDuration: 2-3 days
36Dosing PO Adults PO Children mg per day as a single dose or 2-4 divided doses.PO Children1-3 mg / kg / day. Daily or 2-4 divided doses.
375. Thiazides and Thiazide-Like Diuretics Action: increases excretion of sodium and water by inhibiting sodium reabsorption in the distal tubule.Therapeutic effects: Lowering of blood pressure in hypertensive patients and diuresis with mobilization of edema.Often the first drug used to lower blood pressure.
38Contraindications Allergy to sulfonamides Used cautiously in clients with renal or severe hepatic impairment.
39Adverse Reactions and Side Effects CNS: dizziness, drowsiness, lethargy and weaknessCV: hypotensionGI: anorexia, cramps, hepatitis,Dermatology: photosensitivity, rashesFluid / electrolytes: Hypokalemia, dehydration, hyponatremiaMS: muscle cramps
40hydrochlorothiazide Trade name: Esidrix, HydroDIURIL Therapeutic classification: antihypertensive, diureticIndication:management of mild to moderate hypertensionTreatment of edema associated with CHF, renal dysfunction, cirrhosis, corticosteroid therapy, hormonal therapy
41DosingPO adults: 250 mg – 1 gram / day as a single dose or in divided dosesPO children > 6 months: mg/kg/day as a single dose or in divided doses.
45AnticoagulantA substances that prevents or delays coagulations of the blood.
46Antiplatelet DrugsA substance that prevents platelet plugs from forming, which may be beneficial in defending the body against heart attacks and strokes.
47AnticoagulantsPrevent the formation of a clot by inhibiting certain clotting factors called anticoagulants.Only given prophylactically because they have no direct effect on a clot that has already formed.
48Clots / EmbolusClot: Insoluble solid elements of blood that have chemically separated from the liquid of plasma component of the blood.Embolus: a blood clot that has been dislodged from the wall of a blood vessel and is traveling throughout the bloodstream.
49AnticoagulantsAlso called antithrombotic drugs because they all work to prevent the formation of clots or thrombus.
50EmbolusStoke or cerebral vascular accident occurs when a blood clot travels to the brain.Pulmonary embolism occurs when a blood clot travels to the lungs.Deep vein thrombosis or DVT: clot in the veins of the legs.
51AnticoagulantsAll anticoagulants work in the clotting cascade, but do so at different points.
52Heparin Therapeutic classification: anticoagulants Pharmacologic classification: AntithroboticAction of heparin is to turn off the coagulation pathway and prevent clots from forming.
53IndicationsProphylaxis and treatment of various thromboembolic disorders including:Venous thromboembolismPulmonary embolismAtrial fibrillation with embolizationAcute and chronic coagulopahtiesUsed in low doses to maintain patency of IV catheters (heparin flush)
54Contraindications Uncontrolled bleeding Severe thrombocytopenia Open woundsUse with caution:Severe liver or kidney diseaseUntreated hypertensionUlcer diseaseSpinal cord or brain injury
55Heparin Use with extreme caution: Severe uncontrolled hypertension Bacterial endocarditisBleeding disordersHemorrhagic strokeGI bleeding / ulcersRecent CNS or ophthalmologic surgery
56Drugs that interact with heparin Aspirin (salycilates)NSAIDs
57Dosing IV adults: IV children: Intermittent bolus: 10,000 units followed by 5000 – 10,000 units q 4-6 hoursContinuous drip: 5000 units (35-70 units / kg)SubQ: 800 to 10,000 units q 8 hours or 15,000 to 20,000 units every 12 hoursIV children:Intermittent bolus: 50 units / kg followed by 100 units / kg q 4 hours.
58warfarin Trade name: Coumadin Therapeutic classification: antigoagulantsPharmacologic classification: coumarinsAction: Interferes with hepatic synthesis of vitamin K – dependent clotting factors (II, VII, IX and X)Used to prevent thromboembolic events
59Adverse Reactions and Side Effects GI: cramps and nauseaDerm: dermal necrosisHemat: Bleeding
60DosingPO adults: 2.5 – 10 mg / day for 2-4 days and then dose adjusted by results of prothrombin time (PT) or international normalized ration (INR).Use lower doses in the geriatric population.
61Laboratory ValuesProthrombin time (PT): measures how long it takes a clot to form in a sample of blood.PT 1.3 to 1.5International normalization rate (INR): a standardized measure of coagulation achieved by drug therapy.INR of 2.0 to 3.0
62Nursing Responsibilities Take exactly as directedIf a dose is missed take as soon possibleDo not double up on dosesReview food high in vitamin KVitamin K is antidote for warfarin overdoseInstruct on brushing teeth with soft brush.Report any unusual bleeding or bruising
63Foods high in Vitamin K Green leafy vegetables Prunes Noodles: spinach Pie crusts
64enoxaparin Trade name: Lovenox Therapeutic classification: anticoagulantPharmacologic classification: antithromboticA prototype of heparin – replacing the use of heparin since laboratory values do not need to be monitored so tightly.
65LovenoxAction: Potentiates the inhibitory effect of antithrombin on factor Xa and thrombin.Used to control formation of emboli production post surgery.
66Dosing DVT prophylaxis before knee / hip surgery 30 mg SC twice a day starting within 24 hours post-op and continuing for 7 – 10 days or until ambulating.
71CholesterolA fat-soluble crystalline steroid alcohol found in animal fats and oils and egg yoke and widely distributed in the body especially in the bile, blood, brain tissue, liver kidneys, adrenal glands and myelin sheaths of nerve fibers.
72Cholesterol Levels LDL: low density cholesterol HDL: high density cholesterol (good cholesterol)
73Why is high LDL a problem? Atherosclerotic plaque formationHigh correlation between Coronary Artery Disease (CAD) and high LDL and low HDL.
74Treatment Guidelines Current guidelines recommendations: LDL levels exceeding 190LDL levels of 160 to 190 with CADOther risk factorsWaist circumference greater than 40 inchesSerum triglycerides of 150 or greaterHDL cholesterol less than 40Blood pressure of 130/85 or higherFasting serum glucose greater than 110
75StatinsA class of cholesterol-lowering drugs that are more formally known as HMG-CoA reductase inhibitors.First classification developed in 1987.Action: lower the blood cholesterol by decreasing the rate of cholesterol production.Liver requires HMG-CoA reductase to produce cholesterol.
76Contraindications Drug allergy Pregnancy Liver disease or elevation of liver enzymes.
77Adverse Effects Mild transient GI disturbances, rash and headache. CNS: headache, dizziness, blurred vision, fatigue, nightmares, insomnia.Severe side effect: muscle pain (myopathy)Elevation of liver enzymes: need to be monitored about 6-8 weeks after therapy started and yearly thereafter.
78atorvastatisLipitorMost commonly used drug to lower LDL and raise HDLClient needs to have liver enzymes drawn and cholesterol levels drawn 6-8 weeks after they start the drug therapy.Call physician if muscle weakness is noted.
79Niacin Niacin or nicotinc acid is another lipid lowering drug. Higher doses are needed than available in OTC vitamins or niacin pills.Adverse effects: flushing, pruritus (itching) and gastrointestinal disturbances.
80Life Changes Diet: limit intake of high fat foods and animal proteins Increase intake of omega oil contained in fishExerciseWeight control