Dosing & Uses
Dosage Forms & Strengths
tablet
- 50mg
oral suspension
- 5mg/mL (300-mL multidose bottle)
oral film
- 50mg
Amyotrophic Lateral Sclerosis
50 mg PO q12hr
Also see Administration
Dosage Modifications
Hepatic impairment
- Mild or moderate (Child-Pugh A or B): Patients had increases in AUC; thus, may be at increased risk of adverse reactions
- Severe (Child-Pugh C): Unknown
- Not recommended for patients with baseline serum aminotransferases (AST/ALTs) >5x ULN or evidence of liver dysfunction (eg, elevated bilirubin)
Dosing Considerations
Measure serum AST/ALTs before and during treatment
Huntington Disease (Orphan)
Orphan indication sponsor
- Rhone-Poulenc Rorer Pharmaceuticals, Inc; 500 Arcola Road, PO Box 5096; Collegeville, PA 19426-0800
Ataxia (Orphan)
Orphan designation for treatment of spinocelebellar ataxia
Sponsor
- Biohaven Pharmaceutical Holding Company, Ltd; 234 Church Street, Suite 304; New Haven, Connecticut 06511
Amyotrophic Lateral Sclerosis (Orphan)
Oral suspension (Teglutik [brand name]): Orphan designation for amyotrophic lateral sclerosis (ALS)
Sponsor
- Italfarmaco SpA; 54 Via dei Lavoratori; Cinisello Balsamo, Italy
Safety and efficacy not established
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (3)
- abametapir
abametapir will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.
- givosiran
givosiran will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.
- leniolisib
leniolisib will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid leniolisib with CYP1A2 substrates that have a narrow therapeutic index
Monitor Closely (11)
- bupivacaine implant
riluzole, bupivacaine implant. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Local anesthetics may increase the risk of developing methemoglobinemia when concurrently exposed to drugs that also cause methemoglobinemia.
- cannabidiol
cannabidiol, riluzole. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.
- ciprofloxacin
ciprofloxacin will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- dichlorphenamide
dichlorphenamide and riluzole both decrease serum potassium. Use Caution/Monitor.
- fexinidazole
fexinidazole will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- fluvoxamine
fluvoxamine will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- isoniazid
isoniazid will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- pefloxacin
pefloxacin will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- rucaparib
rucaparib will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP1A2 substrates, if clinically indicated.
- stiripentol
stiripentol, riluzole. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.
- teriflunomide
teriflunomide decreases levels of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
Minor (26)
- amobarbital
amobarbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- armodafinil
armodafinil will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- butabarbital
butabarbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- butalbital
butalbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- carbamazepine
carbamazepine will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- cigarette smoking
cigarette smoking will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- cimetidine
cimetidine will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- erythromycin base
erythromycin base will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- erythromycin lactobionate
erythromycin lactobionate will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- erythromycin stearate
erythromycin stearate will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- food
food decreases levels of riluzole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- mexiletine
mexiletine will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- modafinil
modafinil will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- omeprazole
omeprazole will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- peginterferon alfa 2a
peginterferon alfa 2a will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- pentobarbital
pentobarbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- phenobarbital
phenobarbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- pipemidic acid
pipemidic acid will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- primidone
primidone will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- rifampin
rifampin will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- secobarbital
secobarbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- smoking
smoking will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- tobacco use
tobacco use will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- verapamil
verapamil will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- zileuton
zileuton will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
Adverse Effects
>10%
Oral hypoesthesia (29%)
Asthenia (19%)
Nausea (16%)
1-10%
Decreased lung function (10%)
Hypertension (5%)
Abdominal pain (5%)
Vomiting (4%)
Arthralgia (4%)
Dizziness (4%)
Dry mouth (4%)
Insomnia (4%)
Pruritus (4%)
Tachycardia (3%)
Flatulence (3%)
Increased cough (3%)
Peripheral edema (3%)
Urinary tract infection (3%)
Circumoral paresthesia (2%)
Somnolence (2%)
Vertigo (2%)
Eczema (2%)
Postmarketing Reports
Acute hepatitis
Icteric toxic hepatitis
Renal tubular impairment
Pancreatitis
Warnings
Contraindications
Hypersensitivity to drug or any component of the formulation
Cautions
Cases of severe neutropenia (absolute neutrophil count <500/mm3) within first 2 months of treatment reported; advise patients to report febrile illnesses
Interstitial lung disease, including hypersensitivity pneumonitis, reported in patients receiving therapy; discontinue immediately if interstitial lung disease develops
Hepatic injury
- Cases of drug-induced liver injury reported; asymptomatic elevations of hepatic transaminases reported and recurred in some patients upon rechallenging treatment (see Dosage Modifications)
- Monitor patients for signs and symptoms of hepatic injury, every month for first 3 months of treatment, and periodically thereafter; use is not recommended if patients develop hepatic transaminase levels greater than 5 times the ULN; discontinue therapy if there is evidence of liver dysfunction (eg, elevated bilirubin)
- Case reports of clinical hepatitis reported
Drug interactions overview
- Riluzole is a CYP1A substrate
-
CYP1A2 inhibitors
- In vitro findings suggest coadministration of riluzole with CYP1A2 inhibitors may increase in riluzole exposure
- Coadministration with strong or moderate CYP1A2 inhibitors (eg, ciprofloxacin, enoxacin, fluvoxamine, methoxsalen, mexiletine, oral contraceptives, thiabendazole, vemurafenib, zileuton) may increase risk of riluzole-associated adverse reactions
-
CYP1A2 inducers
- In vitro findings suggest coadministration with CYP1A2 inducers may decrease in riluzole exposure, which may result in decreased efficacy
-
Hepatotoxic drugs
- Clinical trials in ALS patients excluded patients on concomitant medications which were potentially hepatotoxic (eg, allopurinol, methyldopa, sulfasalazine)
Pregnancy & Lactation
Pregnancy
There are no studies in pregnant women, and case reports have been inadequate to inform of drug-associated risk
Unknown if risk of major birth defects and miscarriage in patients with amyotrophic lateral sclerosis
Animal data
- In studies in which riluzole was orally administered to pregnant animals, developmental toxicity (decreased embryofetal/offspring viability, growth, and functional development) was observed at clinically relevant doses
- Based on these results, advise women of possible risks to fetus associated with use of riluzole during pregnancy
- In rats, oral administration of riluzole resulted in decreased fertility indices and increases in embryo lethality
Lactation
Unknown if distributed in human breast milk
Riluzole or its metabolites have been detected in milk of lactating rat
Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for the drug, and any potential adverse effects on the breastfed infant from the drug or from the underlying maternal condition
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Benzothiazole
Mechanism of action in patients with ALS is unknown
Absorption
Bioavailability: ~60%
Peak plasma time: 0.8 hr
Food effects
- Tablet: Decreases AUC by 20% and peak plasma concentration by 45%
- Suspension: Decreases AUC by 9% and peak plasma concentration by 55%
Distribution
Protein binding: 96% (mainly to albumin and lipoproteins)
Metabolism
Metabolized by oxidation via CYP1A2
Direct and sequential glucuronidation: UGT-HP4
Metabolites: 6 major metabolites, some active
Elimination
Half-life: 12 hr
Accumulation: ~ 2-fold
Excretion: Feces (5%); urine (90%)
Pharmacogenomics
Patients of Japanese descent are more likely to have higher riluzole concentrations
In pharmacokinetic analyses, clearance was 50% lower in Japanese males compared with Caucasians, after normalizing for body weight
Mean AUC ~45% higher in females compared with males
Clearance in tobacco smokers is 20% greater than nonsmokers
Administration
Oral Administration
Administer at 1 hr before or 2 hr after a meal
Suspension: Gently shake bottle at least 30 sec prior to administration
Oral film
- Instruct patients and/or caregivers to read the “Instruction for Use” carefully for complete directions on how to properly dose and administer oral films
- Apply on top of the tongue where it adheres and dissolves
- Do not cut or split the film
- Do not administer with liquids
- As film dissolves, swallow saliva in a normal manner, but refrain from chewing, spitting or talking
- Take only 1 oral film at a time
Storage
Tablets and oral films: Store at 20-25ºC (68-77ºF), excursions permitted to 15-30ºC (59-86ºF)
Suspension
- Store at 20-25ºC (68-77ºF), excursions permitted to 15-30ºC (59-86ºF)
- Protect from bright light, do not freeze
- Discard after 15 days of initially opening of the bottle
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
riluzole oral - | 50 mg tablet | ![]() | |
riluzole oral - | 50 mg tablet | ![]() | |
riluzole oral - | 50 mg tablet | ![]() | |
riluzole oral - | 50 mg tablet | ![]() | |
Rilutek oral - | 50 mg tablet | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
riluzole oral
RILUZOLE - ORAL
(RIL-ue-zole)
COMMON BRAND NAME(S): Rilutek, Tiglutik
USES: This medication is used to treat a certain type of nerve disease called amyotrophic lateral sclerosis (ALS, also commonly called Lou Gehrig's disease). Riluzole helps to slow down the worsening of this disease and prolong survival.
HOW TO USE: Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start taking riluzole and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth on an empty stomach (at least 1 hour before or 2 hours after a meal) as directed by your doctor, usually twice daily.If you are using the liquid form of this medication, gently shake the bottle for at least 30 seconds before use. Carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.Tell your doctor if your condition gets worse.
SIDE EFFECTS: Dizziness, drowsiness, nausea, vomiting, or numbness/tingling around the mouth may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: fast heartbeat, signs of liver disease (nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine), signs of infection (such as sore throat that doesn't go away, fever), signs of lung problems (such as shortness of breath, cough).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking riluzole, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease.This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Liquid products may contain sugar and/or aspartame. Caution is advised if you have diabetes, phenylketonuria (PKU), or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (such as prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: mental/mood changes (such as confusion, memory loss), severe drowsiness.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as liver function tests) should be done before you start taking this medication and while you are taking it. Keep all medical and lab appointments. Consult your doctor for more details.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom.If you are using the liquid form of this medication, store the bottle upright. Keep bottle tightly closed between each use. Do not freeze. Use/discard within 15 days after opening. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised August 2021. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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