Mosby's 2014 Nursing Drug Reference (234 page)

ACTION:

Reversibly binds tyrosine kinase of both the epidermal growth factor receptor (ERbB1) and the human epidermal receptor type 2 (HER2) (ERbB2), blocking downstream signaling for cell proliferation

USES:

Advanced metastatic breast cancer patients with tumor that overexpresses HER2 protein and who have received previous chemotherapy

CONTRAINDICATIONS:

Pregnancy (D), breastfeeding, hypersensitivity

Precautions:
Geriatric patients, cardiac disease, bradycardia, hypertension, hypokalemia, hypomagnesemia, QT prolongation, pneumonitis, interstitial lung disease

 

Black Box Warning:

Hepatic disease

DOSAGE AND ROUTES
Calculator
Advanced/metastatic breast cancer with HER2 overexpression who have received previous therapy

• Adult:
PO
1250 mg (5 tabs)/day 1 hr before or after food on days 1-21 plus capecitabine 2000 mg/m
2
/day in 2 divided doses on days 1-14 in a repeating 21-day cycle; continue until therapeutic response or toxicity occurs

Metastatic breast cancer with HER2 overexpression for whom hormonal therapy is indicated

• Adult:
PO
1500 mg (6 tabs) 1 hr before food with letrozole 2.5 mg/day

Hepatic dose

• Adult:
PO
(Child-Pugh C) 750 mg/day (with capecitabine); 1000 mg/day (with letrozole)

Available forms:
Tabs 250 mg

Administer:

• 
Once a day with water on an empty stomach, 1 hr before or after food

• 
Do not use with grapefruit products

SIDE EFFECTS

CNS:
Fatigue, insomnia,
palmar-plantar erythrodysesthesia (hand/foot syndrome)

CV:
Heart failure,
palpitations,
QT prolongation

GI:
Anorexia, diarrhea, dyspepsia, mouth ulcerations, nausea, vomiting, xerosis

HEMA:
Anemia, neutropenia, thrombocytopenia

INTEG:
Rash

RESP:
Dyspnea, pneumonitis

PHARMACOKINETICS

Bioavailability incomplete; peak 4 hr; >99% protein bound; extensively metabolized in the liver by P450 enzymes CYP3A4, CYP3A5; elimination half-life 24 hr; steady state 6-7 days; increased half-life in hepatic disease

INTERACTIONS

 
Increase:
effect of lapatinib—CYP3A4 inhibitors (amiodarone, amprenavir, aprepitant, atazanavir, chloramphenicol, clar
ithromycin, conivaptan, dalfopristin, danazol, darunavir, delavirdine, diltiazem, efavirenz, erythromycin, estradiol, fluconazole, fluvoxaMINE, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, miconazole, mifepristone, nefazodone, nelfinavir, propoxyphene, quinupristin, ritonavir, RU-486, saquinavir, telithromycin, troleandomycin, verapamil, voriconazole, zafirlukast); avoid concurrent use

 
Increase:
QT prolongation—CYP3A4 inhibitors (amiodarone, clarithromycin, erythromycin, telithromycin, troleandomycin); class IA/III antidysrhythmics, arsenic trioxide, chlorproMAZINE, chloroquine, haloperidol, levomethadyl, mesoridazine, pentamine, thioridazine, CYP3A4 substrates (methadone, pimozide, QUEtiapine, quiNIDine, risperiDONE, terfenadine, ziprasidone)

NURSING CONSIDERATIONS
Assess:

• 
Cardiac status:
ECG for QT prolongation, ejection fraction; chest pain, palpitations, dyspnea

• 
Hepatic status:
liver function tests; jaundice of sclera, skin; dose should be reduced in hepatic disease

 
Skin toxicities
NCI CTC grade ≥2 discontinue use in those with decreased left ventricular ejection fraction (LVEF) or for a LVEF that drops below institution’s lower limit of normal; product may be restarted after 2 wk if LVEF recovers to normal at 1000 mg/day; restart at 1250 mg/day when toxicity improves to grade 1 or better

Perform/provide:

• 
Storage at room temp, away from heat

Evaluate:

• 
Therapeutic response: decrease in breast cancer progression

Teach patient/family:

• 
To take with a full glass of water, once a day, 1 hr before or after food; not to take with food or grapefruit products

• 
To take as directed only; if a dose is missed, to take as soon as remembered; if it is close to the next dose, to take only that dose; not to double

 
To report chest pain, difficulty breathing, fever, chills, sore throat, bleeding, bruising, yellow skin or eyes, severe fatigue, dizziness, palpitations to prescriber

• 
That other side effects that may occur, but do not need to be reported: nausea, diarrhea, heartburn, mouth sores, rash, numbness/pain in hands/feet

 
To use adequate contraception because the fetus could be damaged by this product (D)

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

latanoprost
(ophthalmic)

(lah-tan′oh-prost)

Xalatan

Func. class.:
Antiglaucoma agent

Chem. class.:
Prostaglandin agonist

Do not confuse:
latanoprost/
bimatoprost

ACTION:

Increases aqueous humor outflow

USES:

Increased intraocular pressure in those who have open-angle glaucoma/ocular hypertension and who do not respond to other IOP-lowering products

CONTRAINDICATIONS:

Hypersensitivity to this product, benzalkonium chloride

Precautions:
Eye infections, angle-closure glaucoma, renal/hepatic function impairment, children

DOSAGE AND ROUTES
Calculator

• Adult:
OPHTH
Instill 1 drop in each affected eye (conjunctival sac) every night

Available forms:
Ophthalmic solution 0.005%

Administer:
Ophthalmic route

• 
Wash hands before and after use; contact lenses should be removed before using the product, reinsert 15 min after use; contains benzalkonium chloride,
which may be absorbed by soft contact lenses

• 
Tilt the head back slightly and pull the lower eyelid down with the index finger to form a pouch; squeeze the prescribed number of drops into the pouch and gently close the eyes for 1–2 min; do not blink; to avoid contamination, do not touch the tip of the dropper to the eye, fingertips, or other surface

• 
The solution may be used concomitantly with other topical ophthalmic drug products to lower IOP; if more than one topical ophthalmic drug is being used, the drugs should be administered at least 5 min apart

• 
Store unopened bottle refrigerated; once opened, it may be stored at room temperature, protected from light, for up to 6 wk

SIDE EFFECTS

EENT:
Conjunctival hyperemia, iris color change, ocular pruritus
, xerophthalmia, visual disturbance, ocular irritation burning, foreign body sensation, ocular pain, blepharitis, cataracts, and superficial punctate keratitis

INTEG:
Rash

MISC:
Flulike symptoms

PHARMACOKINETICS

Ophthalmic: Onset 3-4 hr, peak 8-12 hr; half-life 3 hr

NURSING CONSIDERATIONS
Assess:

• 
Intraocular pressure:
in those with on-going increased IOP

Evaluate:

• 
Decreasing IOP

Teach patient/family:
Ophthalmic route

• 
To wash hands before and after use; that contact lenses should be removed before using product, reinsert 15 min after use; contains benzalkonium chloride, which may be absorbed by soft contact lenses

• 
To tilt the head back slightly and pull the lower eyelid down with the index finger to form a pouch; squeeze the prescribed number of drops into the pouch and gently close the eyes for 1–2 min; not to blink; to avoid contamination, do not touch the tip of the dropper to the eye, fingertips, or other surface

• 
That the solution may be used concomitantly with other topical ophthalmic drug products to lower IOP; if more than one topical ophthalmic drug is being used, the drugs should be administered at least 5 minutes apart

• 
To store unopened bottle refrigerated; that once opened, it may be stored at room temperature, protected from light, for up to 6 wk

Other books

Rainwater by Sandra Brown
Merlin's Misfortune by Hearn, Shari
Amethyst by Heather Bowhay
Centyr Dominance by Michael G. Manning
Owl and the Japanese Circus by Kristi Charish
Succession by Cameron, Alicia
Flying Changes by Gruen, Sara