riluzole

General

Genetic Implications:

Pronunciation:
ril-yoo-zole

Trade Name(s)

Exservan
Rilutek
Tiglutik

Ther. Class.

agents for amyotrophic lateral sclerosis

Indications

Amyotrophic lateral sclerosis (ALS).

Action

Action may be related to:

Inhibition of glutamate release,
Inactivation of sodium channels,
Interference with neurotransmitter binding at receptor sites.

Therapeutic Effect(s):

Extended survival or time to tracheostomy in ALS.

Pharmacokinetics

Absorption: Well absorbed (60%) after oral administration.

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

ROUTE	ONSET	PEAK	DURATION
PO	unknown	unknown	unknown

Contraindication/Precautions

Contraindicated in:

Severe hypersensitivity.

Use Cautiously in:

Hepatic impairment;
Japanese patients (may have ↑ risk of adverse reactions);
Female patients (↓ metabolism);
OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding;
Pedi: Safety and effectiveness not established in children.

Adverse Reactions/Side Effects

CV: hypertension, peripheral edema

GI: abdominal pain, nausea, anorexia, diarrhea, dyspepsia, flatulence, HEPATOTOXICITY, ↑ liver enzymes, vomiting

Hemat: neutropenia

Metabolic: weight loss

MS: arthralgia, back pain

Neuro: dizziness, weakness, circumoral paresthesia, headache

Resp: INTERSTITIAL LUNG DISEASE (ILD)

Misc: ANAPHYLAXIS

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

Effects may be ↑ by amitriptyline, caffeine, fluoroquinolones, or theophylline.
Effects may be ↓ by cigarette smoke ( nicotine ), rifampin, or omeprazole.

Drug-Natural Products:

St. John's wort may ↓ levels and effectiveness.

Drug-Food:

Effects may be ↓ by charcoal-broiled foods.
High-fat meals ↓ absorption.

Route/Dosage

PO (Adults): 50 mg every 12 hr.

Availability (generic available)

Oral films (Exservan): 50 mg

Oral suspension (Tiglutik): 50 mg/10 mL

Tablets: 50 mg

Assessment

Assess patient for aggravation reaction causing worsening of ALS symptoms (unusual tiredness or weakness, spasticity, diarrhea, nausea, vomiting). May require dose ↓.
May cause ILD. Assess respiratory status (hypersensitivity pneumonitis). Discontinue therapy immediately if ILD is suspected.

Lab Test Considerations:

Monitor AST, ALT, serum bilirubin, and GGT before and during therapy. Monitor serum ALT monthly for the 1st 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.

Implementation

PO Administer on an empty stomach 1 hr before or 2 hr after meals.
- Solution may also be administered via PEG tube. Shake bottle gently for at least 30 sec before administration. Solution is slightly brown and opaque. Store at room temperature and protect from bright light. Discard bottle and unused solution 15 days after first opening bottle.
- Place the oral film on tongue, where it will disintegrate within approximately 2 min and can be swallowed with saliva. No liquid is needed. Do not cut or split the film. Do not chew, spit, or talk while film dissolves.

Patient/Family Teaching

Explain purpose and side effects of medication to patient. Advise patient to read Patient Information before starting therapy. Instruct patient to take 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 ↑ or double doses. Higher doses do not ↑ effectiveness but do ↑ the incidence of side effects.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications, especially St. John's wort.
May cause drowsiness or dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
Advise patient to notify health care professional immediately if signs and symptoms of liver injury (unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, jaundice, dark urine) or interstitial lung disease (dry cough, difficult or labored breathing) occur.
Instruct patient to notify health care professional of any febrile illnesses.
Advise patient to avoid drinking alcohol while taking riluzole.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

Evaluation/Desired Outcomes