Mosby's 2014 Nursing Drug Reference (187 page)

BOOK: Mosby's 2014 Nursing Drug Reference
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Canada only   Side effects:
italics
= common;
bold
= life-threatening   
Nurse Alert

foscarnet (Rx)

(foss-kar′net)

Foscavir

Func. class.:
Antiviral

Chem. class.:
Inorganic pyrophosphate organic analog

ACTION:

Antiviral activity is produced by selective inhibition at the pyrophosphate binding site on virus-specific DNA polymerases and reverse transcriptases at concentrations that do not affect cellular DNA polymerases

USES:

Treatment of CMV retinitis, HSV infections; used with ganciclovir for relapsing patients

CONTRAINDICATIONS:

Hypersensitivity, CCr <0.4 ml/min/kg

Precautions:
Pregnancy (C), breastfeeding, children, geriatric patients, seizure disorders, severe anemia

 

Black Box Warning:

Renal disease, electrolyte/mineral imbalances

DOSAGE AND ROUTES
Calculator
Acyclovir-resistant mucocutaneous herpes simplex virus infection (herpes labialis, herpes febrilis, herpes genitalis) in HIV-infected patients

• Adult/adolescent (unlabeled):
IV
40 mg/kg every 8–12 hr × 2–3 wk or until lesions are healed

Cytomegalovirus (CMV) encephalitis (unlabeled); CMV neurological disease (unlabeled) (including encephalitis) in HIV-infected patients

• Adult/adolescent:
IV
90 mg/kg every 12 hr or 60 mg/kg every 8 hr × 3 wk (or until symptomatic improvement) with ganciclovir 5 mg/kg IV every 12 hr × 2–3 wk

Encephalitis (unlabeled) caused by human herpesvirus 6 (HHV-6) in immunocompromised patients

• Adult:
IV
60 mg/kg every 8 hr or 90 mg/kg every 12 hr alone or in combination with ganciclovir 5 mg/kg IV every 12 hr

CMV retinitis or disseminated disease (unlabeled) in HIV-infected patients, recurrent or relapsed CMV retinitis in HIV-infected patients

• Adult:
IV
Induction with 90 mg/kg every 12 hr or 60 mg/kg IV every 8 hr × 14–21 days, depending upon the clinical response

Renal dose

• 
HSV induction dosage equivalent to 80 mg/kg/day (40 mg/kg IV every 12 hr)

• Adult:
IV
CCr >1.4 ml/min/kg: No change; CCr > 1–1.4 ml/min/kg: Decrease to 30 mg/kg every 12 hr; CCr >0.8–1 ml/min/kg: Decrease to 20 mg/kg every 12 hr; CCr >0.6–0.8 ml/min/kg: Decrease to 35 mg/kg every 24 hr; CCr >0.5–0.6 ml/min/kg: Decrease to 25 mg/kg every 24 hr; CCr ≥0.4–0.5 ml/min/kg: Decrease to 20 mg/kg every 24 hr; CCr <0.4 ml/min/kg: Not recommended

HSV induction dosage equivalent to 120 mg/kg/day (40 mg/kg IV every 8 hr)

• Adult:
IV
CCr >1.4 ml/min/kg: No change; CCr >1–1.4 ml/min/kg: Decrease to 30 mg/kg every 8 hr; CCr >0.8–1 ml/min/kg: Decrease to 35 mg/kg every 12 hr; CCr >0.6–0.8 ml/min/kg: Decrease to 25 mg/kg every 12 hr; CCr 0.5–0.6 ml/min/kg: Decrease to 40 mg/kg every 24 hr; CCr ≥0.4–0.5 ml/min/kg: Decrease to 35 mg/kg every 24 hr; CCr <0.4 ml/min/kg: Not recommended

CMV induction dosage equivalent to 180 mg/kg/day (60 mg/kg every 8 hr)

• Adult:
IV
CCr >1.4 ml/min/kg: No change; CCr >1–1.4 ml/min/kg: Decrease to 45 mg/kg every 8 hr; CCr
>0.8–1 ml/min/kg: Decrease to 50 mg/kg every 12 hr; CCr >0.6–0.8 ml/min/kg: Decrease to 40 mg/kg every 12 hr; CCr >0.5–0.6 ml/min/kg: Decrease to 60 mg/kg every 24 hr; CCr ≥0.4–0.5 ml/min/kg: Decrease to 50 mg/kg every 24 hr; CCr <0.4 ml/min/kg: Not recommended

CMV induction dosage equivalent to 180 mg/kg/day (90 mg/kg IV every 12 hr)

• Adult:
IV
CCr >1.4 ml/min/kg: No change; CCr >1–1.4 ml/min/kg: Decrease to 70 mg/kg every 12 hr; CCr >0.8–1 ml/min/kg: Decrease to 50 mg/kg every 12 hr; CCr >0.6–0.8 ml/min/kg: Decrease to 80 mg/kg every 24 hr; CCr >0.5–0.6 ml/min/kg: Decrease to 60 mg/kg every 24 hr; CCr ≥0.4–0.5 ml/min/kg: Decrease to 50 mg/kg every 24 hr; CCr <0.4 ml/min/kg: Not recommended

Available forms:
Inj 6000 mg/250 ml, 12,000 mg/500 ml (24 mg/ml)

Administer:

• 
Increased fluids before and during product administration to induce diuresis, minimize renal toxicity

Intermittent IV INF route

• 
Using inf device at no more than 1 mg/kg/min; do not give by rapid or bolus IV; give by CVP or peripheral vein; standard 24 mg/ml sol may be used without dilution if using by CVP; dilute the 24 mg/ml sol to 12 mg/ml with D
5
W or NS if using peripheral vein

• 
Manufacturer recommends product not be given with other medications in syringe or admixed

SIDE EFFECTS

CNS:
Fever
, dizziness,
headache
,
seizures,
fatigue
, neuropathy, asthenia, encephalopathy, malaise, meningitis,
paresthesia
, depression,
confusion
,
anxiety

CV:
ECG abnormalities, 1st-degree AV block, nonspecific ST-T segment changes, cerebrovascular disorder,
cardiomyopathy, cardiac arrest, atrial fibrillation, CHF, sinus tachycardia

GI:
Nausea
,
vomiting, diarrhea, anorexia
, abdominal pain,
pancreatitis

GU:
Acute renal failure,
decreased CCr, increased serum creatinine, azotemia, diabetes insipidus,
renal tubular disorders

HEMA:
Anemia
,
granulocytopenia, leukopenia, thrombocytopenia, thrombosis,
neutropenia, lymphadenopathy

INTEG:
Rash
, sweating, pruritus, skin discoloration

RESP:
Coughing
,
dyspnea
, pneumonia,
pulmonary infiltration, pneumothorax, hemoptysis

SYST:
Hypokalemia
,
hypocalcemia
,
hypomagnesemia
; hypophosphatemia

PHARMACOKINETICS

14%-17% protein bound, half-life 18-88 hr in normal renal function, 79%-92% excreted via kidneys

INTERACTIONS

 

Black Box Warning:

Increase:
nephrotoxicity—acyclovir, cidofovir, CISplatin, gold compounds, penicillamine, tacrolimus, tenofovir, vancomycin, aminoglycosides, amphotericin B, NSAIDs, lithium, cycloSPORINE

Increase:
hypocalcemia—pentamidine

NURSING CONSIDERATIONS
Assess:

 

Black Box Warning:

Renal tubular disorders:
I&O ratio, urine pH, serum creatinine at baseline, 3×/wk during initial therapy then 2×/wk thereafter; CCr at baseline, throughout treatment; if CCr <0.4 ml/min/kg, discontinue

• 
Blood counts q2wk; watch for decreasing granulocytes, Hgb; if low, therapy may have to be discontinued and restarted after hematologic recovery; blood transfusions may be required

• 
Lesions in HSV

• 
Electrolytes and minerals (calcium, phosphate, magnesium, potassium); watch closely for tetany during 1st administration

• 
GI symptoms: nausea, vomiting, diarrhea; severe symptoms may necessitate discontinuing product

 
Blood dyscrasias
(anemia, granulocytopenia): bruising, fatigue, bleeding, poor healing

• 
Allergic reactions:
flushing, rash, urticaria, pruritus

CMV retinitis

• 
Culture should be performed prior to treatment (blood, urine, throat); a negative culture does not rule out CMV

• 
Ophthalmic exam should confirm diagnosis

Perform/provide:

• 
Close monitoring during therapy for tingling, numbness, paresthesias; if these occur, stop inf, obtain lab sample for electrolytes

Evaluate:

• 
Therapeutic response: improvement in CMV retinitis

Teach patient/family:

• 
To call prescriber if sore throat, swollen lymph nodes, malaise, fever occur, since other infections may occur

• 
To report perioral tingling, numbness in extremities, and paresthesias

• 
That serious product interactions may occur if OTC products are ingested; check first with prescriber

• 
That product is not a cure but will control symptoms

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

fosinopril (Rx)

(foss′in-oh-pril)

Monopril

Func. class.:
Antihypertensive

Chem. class.:
Angiotensin-converting enzyme (ACE) inhibitor

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