Mosby's 2014 Nursing Drug Reference (424 page)

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HIGH ALERT
warfarin (Rx)

(war′far-in)

Coumadin, Jantoven

Func. class.:
Anticoagulant

Chem. class.:
Coumarin derivative

Do not confuse:
Coumadin
/Cardura/Compazine

ACTION:

Interferes with blood clotting by indirect means; depresses hepatic synthesis of vit-K–dependent coagulation factors (II, VII, IX, X)

USES:

Antiphospholipid antibody syndrome, arterial thromboembolism prophylaxis, DVT, MI prophylaxis, after MI,
stroke prophylaxis, thrombosis prophylaxis

Unlabeled uses:
Angina, unstable angina

CONTRAINDICATIONS:

Pregnancy (X), breastfeeding, hypersensitivity, hemophilia, leukemia with bleeding, peptic ulcer disease, thrombocytopenic purpura, hepatic disease (severe), malignant hypertension, subacute bacterial endocarditis, acute nephritis, blood dyscrasias, eclampsia, preeclampsia, hemorrhagic tendencies; surgery of CNS, eye; traumatric surgery with large open surface, bleeding tendencies of GI/GU/respiratory tract, stroke, aneurysms, pericardial effusion, spinal puncture, major regional/lumbar block anesthesia

 

Black Box Warning:

Bleeding

Precautions:
Geriatric patients, alcoholism, CHF, debilitated patients, trauma, indwelling catheters, severe hypertension, active infections, protein C deficiency, polycythemia vera, vasculitis, severe diabetes, Asian patients (CYP2C9), protein C, S deficiency

DOSAGE AND ROUTES
Calculator

• Adult:
PO/IV
2.5-10 mg/day × 2-4 days then titrated to INR/PT

• Adolescent/child/infant:
PO/IV
0.2 mg/kg/day × 2 days titrated to INR

Available forms:
Tabs 1, 2, 2.5, 3, 4, 5, 6, 7.5, 10 mg; inj 5 mg powder for inj

Administer:
PO route

• 
At same time each day to maintain steady blood levels without regard to food; food decreases rate but not extent of absorption; do not change brands

• 
Tabs whole or crushed

• 
Avoiding all IM inj that may cause bleeding

Direct IV route

• 
Reconstitute with 2.7 ml sterile water for inj (2 mg/ml); do not use sol that is discolored or that has particulates

• 
Give over 1-2 min into peripheral vein

Y-site compatibilities:
Amikacin, ascorbic acid, bivalirudin, ceFAZolin, cefTRIAXone, DOPamine, EPINEPHrine, heparin, lidocaine, metaraminol, morphine, nitroglycerin, oxytocin, potassium chloride, ranitidine

SIDE EFFECTS

CNS:
Fever
, dizziness, fatigue, headache, lethargy

CV:
Angina, chest pain, edema, hypotension, syncope

GI:
Diarrhea
, nausea, vomiting, anorexia, stomatitis, cramps,
hepatitis,
cholestatic jaundice

GU:
Hematuria

HEMA:
Hemorrhage, agranulocytosis, leukopenia, eosinophilia,
anemia, ecchymosis, petechiae

INTEG:
Rash
, dermatitis, urticaria, alopecia, pruritus

MISC:
Epistaxis, hemoptysis, mouth ulcers, taste disturbances, priapism, dyspnea

MS:
Bone fractures

SYST:
Anaphylaxis,
coma, cholesterol, microembolism,
exfoliative dermatitis, purple toe syndrome

PHARMACOKINETICS

PO:
Onset 12-24 hr, peak 1½-4 days, duration 3-5 days, effective half-life 20-60 hr; metabolized in liver; excreted in urine, feces (active/inactive metabolites); crosses placenta, 99% bound to plasma proteins

INTERACTIONS

Increase:
warfarin action—allopurinol, amiodarone, chloral hydrate, chloramphenicol, cimetidine, clofibrate, cotrimoxazole, COX-2 selective inhibitors, dextrothyroxine, diflunisal, disulfiram, erythromycin, ethacrynic acids, furosemide, glucagon, heparin, HMG-CoA reductase inhibitors, indomethacin, isoniazid, mefenamic acid, metroNIDAZOLE, mifepristone, NSAIDs, oxyphenbutazones, penicillins, phenylbutazone, quiNIDine, quinolone antiinfectives, RU-486,
salicylates, sulfinpyrazone, sulfonamides, sulindac, SSRIs, steroids, thrombolytics, thyroid, tricyclics

Increase:
toxicity—oral sulfonylureas, phenytoin

Decrease:
warfarin action—aprepitant, azaTHIOprine, barbiturates, bile acid sequestrants, bosentan, carBAMazepine, dicloxacillin, estrogens, ethchlorvynol, factor IX/VIIa, griseofulvin, nafcillin, oral contraceptives, phenytoin, rifampin, sucralfate, sulfaSALAzine, thyroid, vit K, vit K foods

Drug/Herb

Increase:
risk for bleeding—angelica, anise, basil, chamomile, chondroitin, dong quai, evening primrose, feverfew, garlic, ginger, ginkgo, ginseng, horse chestnut, kava, licorice, melatonin, red yeast rice, saw palmetto

Decrease:
anticoagulant effect—coenzyme Q10, St. John’s wort

Drug/Lab Test

Increase:
T
3
uptake, LFTs

Decrease:
uric acid

NURSING CONSIDERATIONS
Assess:

 

Black Box Warning:

Blood studies (Hct, PT, platelets, occult blood in stools) q3mo; INR: in hospital daily after 2nd or 3rd dose; when in therapeutic range for 2 consecutive days, monitor 2-3× wk for 1-2 wk then less frequently, depending on stability of INR results;
Outpatient:
monitor every few days until stable dose then periodically thereafter, adepending on stability of INR results, usually at least monthly

 

Black Box Warning:

Bleeding gums, petechiae, ecchymosis, black tarry stools, hematuria; fatal hemorrhage can occur

 
Fever, skin rash, urticaria

Perform/provide:

• 
Storage in tight container

Evaluate:

• 
Therapeutic response: decrease in deep venous thrombosis

Teach patient/family:

• 
To avoid OTC preparations that may cause serious product interactions unless directed by prescriber

• 
To carry emergency ID identifying product taken

• 
About the importance of compliance

• 
To report any signs of bleeding: gums, under skin, urine, stools; to use soft-bristle toothbrush to avoid bleeding gums; to use electric razor

• 
To avoid hazardous activities (eg, football, hockey, skiing), dangerous work

• 
About the importance of avoiding unusual changes in vitamin intake, diet, or lifestyle

• 
To inform all health care providers of anticoagulant intake

TREATMENT OF OVERDOSE:

Administer vit K

Canada only   Side effects:
italics
= common;
bold
= life-threatening   
Nurse Alert

xylometazoline nasal
agent

See
Appendix B

Canada only   Side effects:
italics
= common;
bold
= life-threatening   
Nurse Alert

zafirlukast (Rx)

(za-feer′loo-cast)

Accolate

Func. class.:
Bronchodilator

Chem. class.:
Leukotriene receptor antagonist

ACTION:

Antagonizes the contractile action of leukotrienes (LTD
4
, LTE
4
) in airway smooth muscle; inhibits bronchoconstriction caused by antigens

USES:

Prophylaxis and chronic treatment of asthma in adults/children >5 yr

Unlabeled uses:
Allergic rhinitis

CONTRAINDICATIONS:

Hypersensitivity, hepatic encephalopathy

Precautions:
Pregnancy (B), breastfeeding, children, geriatric patients, hepatic disease, Churg-Strauss syndrome, acute bronchospasm

DOSAGE AND ROUTES
Calculator

• Adult and child ≥12 yr:
PO
20 mg bid

• Child 5-11 yr:
PO
10 mg bid

Available forms:
Tabs 10, 20 mg

Administer:

• 
1 hr before or 2 hr after meals; absorption may be decreased if given with food

SIDE EFFECTS

CNS:
Headache, dizziness,
suicidal ideation,
insomnia, fever

GI:
Nausea, diarrhea, abdominal pain, vomiting, dyspepsia,
hepatic failure, hepatitis

HEMA:
Agranulocytosis

OTHER:
Infections, pain, asthenia, myalgia, fever, increased ALT, urticaria, rash,
angioedema

PHARMACOKINETICS

Rapidly absorbed, peak 3 hr, 99% protein binding (albumin), extensively metabolized, inhibits CYP2C9 and 3A4 enzyme systems, excreted in feces, clearance reduced in geriatric patients, hepatic impairment, half-life 10 hr

INTERACTIONS

Increase:
plasma levels of zafirlukast—aspirin

Increase:
PT—warfarin

Decrease:
plasma levels of zafirlukast—erythromycin, theophylline

Drug/Food

Decrease:
bioavailability

NURSING CONSIDERATIONS
Assess:

 
Adult patients carefully for symptoms of Churg-Strauss syndrome
(rare), including eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, neuropathy, may be caused by reducing oral corticosteroids

• 
Respiratory rate, rhythm, depth; auscultate lung fields bilaterally; notify prescriber of abnormalities, not to be used for acute bronchospasm in acute asthma

• 
Hepatic disease:
monitor liver function tests

Evaluate:

• 
Therapeutic response: ability to breathe more easily

Teach patient/family:

• 
To check OTC medications, current prescription medications that may increase stimulation

• 
To avoid hazardous activities because dizziness may occur

• 
That, if GI upset occurs, to take product with 8 oz water; to avoid taking with food if possible because absorption may be decreased

• 
To notify prescriber of nausea, vomiting, diarrhea, abdominal pain, fatigue, jaundice, anorexia, flulike symptoms (hepatic dysfunction)

• 
Not to use for acute asthma episodes

• 
Not to take if breastfeeding

• 
To take even if symptom free

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