Mosby's 2014 Nursing Drug Reference (232 page)

BOOK: Mosby's 2014 Nursing Drug Reference
10.24Mb size Format: txt, pdf, ePub

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

lamiVUDine 3TC (Rx)

(lam-i-voo′deen)

Epivir, Epivir HBV

Func. class.:
Antiretroviral

Chem. class.:
Nucleoside reverse transcriptase inhibitor (NRTI)

Do not confuse:
lamiVUDine
/lamoTRIgine

ACTION:

Inhibits replication of HIV virus by incorporating into cellular DNA by viral reverse transcriptase, thereby terminating cellular DNA chain

USES:

HIV-1 infection in combination with at least 2 other antiretrovirals; chronic hepatitis B (Epivir-HBV)

Unlabeled uses:
Prophylaxis of HIV: postexposure with indinavir and zidovudine

CONTRAINDICATIONS:

Hypersensitivity

 

Black Box Warning:

Lactic acidosis

Precautions:
Pregnancy (C), breastfeeding, children, geriatric patients, granulocyte count <1000/mm
3
or Hgb <9.5 g/dl, renal disease, pancreatitis, peripheral neuropathy

 

Black Box Warning:

Severe hepatic dysfunction

DOSAGE AND ROUTES
Calculator
HIV

• Adult and adolescent >16 yr:
PO
150 mg bid or 300 mg/day

• Child 3 mo-16 yr:
PO
4 mg/kg bid, max 150 mg bid

Chronic hepatitis B

• Adult:
PO
100 mg/day

• Child and adolescent 2-17 yr:
PO
3 mg/kg/day, max 100 mg

Renal dose

• Adult:
PO
CCr 30-49 ml/min: Epivir 150 mg/day; Epivir HBV 100 mg 1st dose then 50 mg/day; CCr 15-29 ml/min: Epivir 150 mg 1st dose then 100 mg/day; Epivir HBV 100 mg 1st dose then 25 mg/day; CCr 5-14 ml/min: Epivir 150 mg 1st dose then 50 mg/day; Epivir HBV 35 mg 1st dose then 15 mg/day; CCr <5 ml/min: Epivir 50 mg 1st dose then 25 mg/day; Epivir HBV 35 mg 1st dose then 10 mg/day

Available forms:
(Epivir)
oral sol 10 mg/ml; tabs 150, 300 mg; (
Epivir HBV
) oral sol 5 mg/ml; tabs 100 mg

Administer:

• 
PO daily or bid, without regard to meals

• 
Epivir and Epivir HBV are not interchangeable

• 
With other antiretrovirals only

SIDE EFFECTS

CNS:
Fever, headache, malaise, dizziness, insomnia, depression, fatigue, chills
,
seizures,
peripheral neuropathy, paresthesias

EENT:
Taste change, hearing loss, photophobia

GI:
Nausea, vomiting, diarrhea
, anorexia, cramps, dyspepsia,
hepatomegaly with steatosis, pancreatitis

HEMA:
Neutropenia, anemia, thrombocytopenia

INTEG:
Rash

MS:
Myalgia, arthralgia, pain

RESP:
Cough

SYST:
Lactic acidosis, anaphylaxis, Stevens-Johnson syndrome

PHARMACOKINETICS

Rapidly absorbed, distributed to extravascular space, excreted unchanged in urine, protein binding <36%, terminal half-life 5-7 hr

INTERACTIONS

Decrease:
both products—zalcitabine; avoid concurrent use

Increase:
lamiVUDine level—trimethoprim-sulfamethoxazole, amiloride, dofetilide, entecavir, metformin, memantine, procainamide, trospium

• 
Do not use with emtricitabine, duplication

Decrease:
lamiVUDine effect—interferons

Drug/Lab Test

Increase:
ALT, bilirubin

Decrease:
Hgb, neutrophil, platelet count

NURSING CONSIDERATIONS
Assess:

• 
HIV:
Test for HIV before starting treatment, blood counts q2wk; watch for neutropenia, thrombocytopenia, Hgb, CD4, viral load; if low, therapy may have to be discontinued and restarted after hematologic recovery; blood transfusions may be required; assess for lessening of symptoms; if HBV is present, a higher dose of Epivir-HBV is needed

• 
Hepatitis B:
fatigue, anorexia, pruritus, jaundice during and for several months after discontinuation; AST, ALT, bilirubin; amylase, lipase, triglycerides, periodically during treatment

• 
Children for pancreatitis:
abdominal pain, nausea, vomiting, neuropathy

 

Black Box Warning:

Lactic acidosis, severe hepatomegaly with steatosis: obtain baseline LFTs, if elevated, discontinue treatment; discontinue even if LFTs are normal if lactic acidosis, severe hepatomegaly develops, may be fatal

Perform/provide:

• 
Storage in cool environment; protect from light

Evaluate:

• 
Decreasing symptoms of HIV, CD4, viral load

Teach patient/family:

• 
That GI complaints, insomnia resolve after 3-4 wk of treatment

• 
That product is not a cure for HIV but will control symptoms; that compliance is necessary; to take as directed; to complete full course of treatment even if feeling better

• 
To notify prescriber of sore throat, swollen lymph nodes, malaise, fever, peripheral neuropathy; other infections may occur

• 
That patient is still infective, may pass HIV virus on to others

• 
That follow-up visits must be continued since serious toxicity may occur; that blood counts must be done

• 
That other products may be necessary to prevent other infections

• 
That product may cause fainting or dizziness

• 
Not to breastfeed, excreted in breast milk

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

lamoTRIgine (Rx)

(la-moe′tri-geen)

LaMICtal, LaMICtal CD, LaMICtal ODT, LaMICtal XR

Func. class.:
Anticonvulsant—miscellaneous

Chem. class.:
Phenyltriazine

Do not confuse:
lamoTRIgine
/lamiVUDine
LaMICtal
/Lomotil/LamISIL

ACTION:

Inhibits voltage-sensitive sodium channels, thus decreasing seizures

USES:

Adjunct for the treatment of partial, tonic-clonic seizures; children with Lennox-Gastaut syndrome, bipolar disorder

Unlabeled uses:
Absence, seizures

CONTRAINDICATIONS:

Hypersensitivity

Precautions:
Pregnancy (C) (cleft lip/palate during 1st trimester), breastfeeding, geriatric patients, cardiac/renal/hepatic disease, severe depression, suicidal, blood dyscrasias

 

Black Box Warning:

Children <16 yr

DOSAGE AND ROUTES
Calculator
Seizures: monotherapy

• Adult and adolescent ≥16 yr:
PO
50 mg/day while receiving 1 enzyme-inducing AED (carBAMazepine, PHENobarbital, phenytoin, primidone but not valproic acid) wk 1-2, then increase to 100 mg divided bid wk 3-4; maintenance 300-500 mg/day; EXT REL 50 mg/day × 1-2 wk, then 100 mg/day wk 3-4, then 200 mg/day wk 5, then 300 mg/day wk 6, then 400 mg/day wk 7; after wk 7, range is 400-600 mg/day

• Adolescent <16 yr and child:
PO
0.3 mg/kg/day wk 1-2, then 0.6 mg/kg/day wk 3-4; depends on use of AED; usual dose 4.5-7.5 mg/kg/day, max 300 mg/day

Monotherapy for patients taking valproate

• Adult and adolescent ≥16 yr receiving lamotrigine and valproate without enzyme-inducing drug:
PO
(immediate release) stabilize on valproate, target dose of 200 mg/day lamoTRIgine; if patient is not taking lamoTRIgine 200 mg/day, increase dose by 25-50 mg/day q1-2wk to reach 200 mg/day; while maintaining lamoTRIgine 200 mg/day, decrease valproate to 500 mg/day by ≤500 mg/day/wk, maintain valproate at 500 mg/day × 1 wk, then increase lamoTRIgine to 300 mg/day while decreasing valproate 250 mg/day × 1 wk, then discontinue valproate and increase lamoTRIgine by 100 mg/day/wk to maintenance of 500 mg/day

Seizures: Multiple therapy with valproate

• Adult and adolescent ≥16 yr:
PO
25 mg every other day then 25 mg/day wk 3-4, increase by 25-50 mg q1-2wk, maintenance 100-400 mg/day

• Adolescent <16 yr and child:
PO
0.1-0.2 mg/kg/day initially then increase q2wk as needed to 1-5 mg/kg/day or 200 mg/day

Bipolar disorder (escalation regimen for those not taking carbamazepine, other enzyme-inducing drugs, or valproate)

• Adult and adolescent ≥16 yr:
PO
wk 1-2, 25 mg/day; wk 3-4, 50 mg/day; wk 5, 100 mg/day; wk 6-7, 200 mg/day; for patients taking valproic acid: wk 1-2, 25 mg every other day; wk 3-4, 25 mg/day; wk 5, 50 mg/day; wk 6, 100 mg/day; wk 7, 100 mg/day

Hepatic dose

• Adult:
PO
moderate hepatic impairment or severe without ascites: reduce by 25%; severe hepatic impairment with ascites: reduce by 50%

Absence seizures (unlabeled)

• Adolescent and child 3-13 yr:
PO
0.5 mg/kg/day in 2 divided doses × 2 wk then 1 mg/kg/day in 2 divided doses × 2 wk, adjusted q5days

Available forms:
Tabs 25, 100, 150, 200 mg; PO ext rel 25-50-100, 50-100-200 mg titration kit; PO 25-100 mg starter kit; ext rel 25, 50, 100, 250 mg; chew dispersible tabs 5, 25 mg; oral disintegrating tab 25, 50, 100, 200 mg; oral disintegrating tab 25-50, 50-100 mg, 25-50-100 mg titration kit

Administer:

• 
Correct starter kit; errors have occurred

• 
Discontinue all products gradually over ≥2 wk; abrupt discontinuation can increase seizures

• 
Chewable dispersible tab:
may be swallowed whole, chewed, mixed in water or fruit juice; to mix, add to small amount of liquid in glass or spoon; tabs will dissolve in 1 min, then mix in more liquid and swirl and swallow immediately

• 
Orally disintegrating tabs:
place on tongue, move around in mouth, when disintegrated, swallow; examine blister pack before use, do not use if blisters are torn or missing

• 
Extended-release tabs:
swallow whole, do not cut, break, chew; without regard to food

SIDE EFFECTS

CNS:
Dizziness
, ataxia,
headache
, fever, insomnia, tremor, depression, anxiety,
suicidal ideation

EENT:
Nystagmus,
diplopia, blurred vision

GI:
Nausea, vomiting, anorexia, abdominal pain
,
hepatotoxicity

GU:
Dysmenorrhea

HEMA:
Anemia,
DIC, leukopenia, thrombocytopenia

INTEG:
Rash (potentially life-threatening),
alopecia, photosensitivity

SYST:
Stevens-Johnson syndrome, angioedema, toxic epidermal necrolysis

PHARMACOKINETICS

Half-life varies depending on dose; terminal half-life 24 hr, 15 hr with enzyme inducers; rapidly, completely absorbed; metabolized by glucuronic acid conjunction; protein binding 55%; peak 1.4-2.3 hr; crosses placenta; excreted in breast milk

INTERACTIONS

Decrease:
metabolic clearance of lamoTRIgine—valproic acid, CYP3A4 inhibitors

Decrease:
lamoTRIgine concentration—carBAMazepine, rifamycins, oral contraceptives, acetaminophen, phenytoin, primodone, PHENobarbital, OXcarbazepine, succinimides, estrogen

Drug/Herb

Increase:
anticonvulsant effect—ginkgo

Decrease:
anticonvulsant effect—ginseng

NURSING CONSIDERATIONS
Assess:

• 
Seizure:
duration, type, intensity, halo before seizure

 
Rash (Stevens-Johnson syndrome, toxic epidermal necrolysis) in pediatric patients; product should be discontinued at first sign of rash

 
Bipolar disorder:
suicidal thoughts/behaviors

Evaluate:

• 
Therapeutic response: decrease in severity of seizures or of bipolar symptoms

Teach patient/family:

• 
To take PO doses divided, with or after meals to decrease adverse effects; not to discontinue product abruptly because seizures may occur

• 
To avoid hazardous activities until stabilized on product

• 
To carry emergency ID; to notify prescriber of skin rash, increased seizure activity; to use sunscreen, protective clothing if photosensitivity occurs

• 
To notify prescriber if pregnant, intending to become pregnant

• 
To notify prescriber immediately of suicidal thoughts/behaviors

• 
To notify prescriber if pregnancy is planned or suspected, pregnancy (C), product decreases folate, avoid breastfeeding

Other books

When Valentines Collide by Adrianne Byrd
The Blooding by Joseph Wambaugh
Eve by Anna Carey
The Emerald Isle by Angela Elwell Hunt
The Yearbook Committee by Sarah Ayoub
Dawn of Avalon by Anna Elliott
Seizure by Nick Oldham