Rilutek

riluzole

Rilutek

Pharmacologic class: Glutamate antagonist

Therapeutic class: Amyotrophic lateral sclerosis (ALS) agent

Pregnancy risk category C

Action

Unknown. Thought to inhibit amino acid accumulation on motor neurons of CNS, improving nerve impulse transmission.

Availability

Tablets: 50 mg

Indications and dosages

ALS

Adults: 50 mg P.O. q 12 hours

Off-label uses

• Cervical dystonia

• Huntington's disease

Contraindications

• Hypersensitivity to drug or its components

Precautions

Use cautiously in:

• hepatic or renal insufficiency, neutropenia, febrile illness

• elderly patients

• female patients and Japanese patients (may have decreased metabolic capacity to eliminate drug)

• pregnant or breastfeeding patients

• children.

Administration

• Give at least 1 hour before or 2 hours after a meal to maximize absorption.

Adverse reactions

CNS: headache, dizziness, drowsiness, asthenia, hypertonia, depression, insomnia, malaise, vertigo, circumoral paresthesia

CV: hypertension, orthostatic hypotension, tachycardia, palpitations, peripheral edema, phlebitis, cardiac arrest

EENT: rhinitis, sinusitis, oral candidiasis

GI: nausea, vomiting, diarrhea, abdominal pain, dyspepsia, flatulence, stomatitis, dry mouth, anorexia

GU: urinary tract infection, dysuria

Hematologic: neutropenia

Musculoskeletal: back pain, joint pain

Respiratory: decreased lung function, increased cough, pneumonia

Skin: pruritus, eczema, alopecia, exfoliative dermatitis

Other: tooth disorders, weight loss

Interactions

Drug-drug. Allopurinol, methyldopa, sulfasalazine: increased risk of hepatotoxicity

CYP450-1A2 inducers (such as omeprazole, rifampin): increased riluzole elimination

CYP450-1A2 inhibitors (such as amitriptyline, phenacetin, quinolones, theophylline): decreased riluzole elimination

Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, bilirubin, gamma-glutamyltransferase: increased levels

Drug-food. High-fat foods: decreased riluzole absorption

Drug-behaviors. Alcohol use: increased risk of hepatotoxicity

Patient monitoring

• Monitor liver function tests and CBC.

• Assess vital signs and cardiovascular status, particularly for hypertension, orthostatic hypotension, and peripheral edema.

• Closely monitor respiratory status for decreased lung function and pneumonia.

• Monitor weight, nutritional status, and hydration.

• Closely monitor females and patients of Japanese origin, who are at increased risk for adverse reactions.

Patient teaching

• Tell patient to take 1 hour before or 2 hours after a meal, at same time each day.

• Instruct patient to take his temperature regularly and report fever.

See Teach patient to immediately report arm or leg swelling, difficulty breathing, and other signs of decreased lung function.

• Advise patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.

• Caution patient to avoid high-fat foods and alcohol.

• Instruct patient to move slowly when sitting up or standing, to avoid dizziness from sudden blood pressure decrease.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and behaviors mentioned above.

riluzole

(ril-yoo-zole) riluzole,

Rilutek

(trade name)

Classification

Therapeutic: agents amyotrophic lateral sclerosis
Pregnancy Category: C

Indications

Treatment of patients with amyotrophic lateral sclerosis (ALS).

Action

Action may be related to: :
  • Inhibition of glutamate release,
  • Inactivation of sodium channels or,
  • Interference with neurotransmitter binding at receptor sites.

Therapeutic effects

Extended survival or time to tracheostomy in ALS patients.

Pharmacokinetics

Absorption: Well absorbed (90%) after oral administration, but bioavailability is 50%.Distribution: Readily penetrates brain.Protein Binding: 96%.Metabolism and Excretion: Highly metabolized by the liver (some metabolites are pharmacologically active); 2% excreted unchanged in urine.Half-life: 12 hr (after multiple doses).

Time/action profile

ROUTEONSETPEAKDURATION
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Contraindications/Precautions

Contraindicated in: Severe hypersensitivity.Use Cautiously in: Hepatic or renal impairment; Female patients (↓ metabolism); Obstetric / Lactation / Pediatric: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • dizziness (most frequent)
  • weakness (most frequent)
  • headache

Respiratory

  • decreased lung function (most frequent)
  • hypersensitivity pneumonitis
  • interstitial lung disease

Cardiovascular

  • hypertension
  • peripheral edema

Gastrointestinal

  • hepatitis (life-threatening)
  • abdominal pain (most frequent)
  • nausea (most frequent)
  • anorexia
  • diarrhea
  • dyspepsia
  • flatulence
  • ↑ liver enzymes
  • vomiting

Hematologic

  • neutropenia

Metabolic

  • weight loss

Musculoskeletal

  • arthralgia
  • back pain

Neurologic

  • circumoral paresthesia

Interactions

Drug-Drug interaction

Effects may be ↑ by amitriptyline, caffeine, fluoroquinolones, or theophylline.Effects may be ↓ by cigarette smoke (nicotine ), rifampin, or omeprazole.St. John's wort may ↓ levels and effectiveness.Effects may be ↓ by charcoal-broiled foods.High-fat meals ↓ absorption.

Route/Dosage

Oral (Adults) 50 mg q 12 hr.

Availability (generic available)

Tablets: 50 mg

Nursing implications

Nursing assessment

  • Assess patient for aggravation reaction causing worsening of ALS symptoms (unusual tiredness or weakness, spasticity, diarrhea, nausea, vomiting). May require dose reduction.
  • Lab Test Considerations: Monitor AST, ALT, serum bilirubin, and GGT before and during therapy. Monitor serum ALT monthly for the first 3 mo, every 3 mo for the 1st yr, and periodically thereafter. Discontinue treatment if ALT is >5 times the upper limit of normal or if clinical jaundice develops.
    • Monitor WBC in patients with febrile illness.

Potential Nursing Diagnoses

Impaired physical mobility (Indications)
Diarrhea (Adverse Reactions)

Implementation

  • Oral: Administer on an empty stomach 1 hr before or 2 hr after meals.

Patient/Family Teaching

  • Instruct patient to take riluzole as directed at the same time each day on an empty stomach. Missed doses should be omitted; start again at next scheduled dose. Do not increase or double doses. Higher doses do not increase effectiveness but increase the incidence of side effects.
  • May cause drowsiness or dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
  • Advise patient to avoid drinking alcohol while taking riluzole.
  • Instruct patient to notify health care professional of any febrile illnesses.

Evaluation/Desired Outcomes

  • Extended survival or time to tracheostomy in ALS patients.

Riluzole (Rilutek)

The first drug approved in the United States for the treatment of ALS.Mentioned in: Amyotrophic Lateral Sclerosis