Overview - What Singulair Does

Singulair (montelukast) is a leukotriene receptor antagonist. Leukotrienes are inflammatory chemicals that tighten airway muscles and increase mucus. By blocking them, montelukast helps reduce asthma symptoms and allergy-related nasal symptoms. It is for maintenance therapy, not for sudden breathing attacks. Keep a rescue inhaler available for acute symptoms. See What to Watch For.

Age guidance: 10 mg tablet is generally for patients 15 years and older; 5 mg chewable for 6 to 14 years; 4 mg chewable or 4 mg oral granules for younger children (granules can be used from 6 months of age in certain indications). Ask a pediatric clinician about age-specific dosing and indications.

Looking for options beyond montelukast? Jump to Alternatives or compare costs in Prices in the USA.

How to Take It

Take montelukast by mouth as directed on your prescription label. You can take it with or without food. Try to take the dose at the same time each day to build a habit. Swallow standard tablets whole; chew chewable tablets thoroughly; granules may be put directly in the mouth or mixed with a small amount of soft food as per the package directions.

  • If you use it for asthma control, many clinicians suggest an evening dose, but follow your prescriber's exact instructions.
  • For exercise-induced bronchoconstriction, a single dose may be taken at least 2 hours before activity. Do not take an extra exercise dose on top of your daily dose unless your prescriber instructs you to.
  • Do not stop this medicine abruptly unless your clinician advises you to. It is maintenance therapy, not a rescue medication. For acute breathing trouble, use your prescribed quick-relief inhaler.
  • Overdose: If you suspect an overdose, contact a poison control center or go to an emergency department immediately.

For pediatric use and dosing adjustments, discuss details with a pediatric specialist. You can review precautions in Before Using.

Missed Dose

If you miss a dose, take it when you remember unless it is close to the time for your next dose. If it is almost time for the next dose, skip the missed one. Do not double doses.

Before Using - Tell Your Clinician

Inform your health care provider about any medical issues and all products you take so that they can assess safety and dosing. Be sure to mention if any of the following apply to you:

  • History of mood changes, depression, anxiety, sleep disturbances, or suicidal thoughts or behavior.
  • Known liver disease or abnormal liver tests.
  • Allergies or previous reactions to montelukast or any excipients in tablets, chewables, or granules; also list other medication, food, dye, or preservative allergies.
  • Pregnant, planning pregnancy, or breastfeeding.
  • Phenylketonuria (PKU) or sensitivity to sweeteners in chewable tablets.
  • Unexplained fevers, rash, nerve problems, or eosinophilia in the past.

For legal and safety information specific to the USA, see Legal Status and Regulations.

Drug and Herb Interactions

Always share a complete list of your medicines and supplements with your clinician and pharmacist. Items below may interact or require monitoring:

  • Paclitaxel (a CYP2C8 substrate).
  • Medicines for diabetes such as rosiglitazone or repaglinide.
  • Anti-infectives that induce liver enzymes, including rifampin or rifabutin.
  • Medicines for seizures, for example carbamazepine, phenobarbital, or phenytoin.

Some herbal products and lifestyle factors may also matter. For instance, strong enzyme inducers and heavy alcohol use can change how drugs are metabolized. Tell your clinician if you smoke, drink alcohol, or use herbal products like St Johns wort. This list is not exhaustive.

What to Watch For

Keep regular follow-up with your health care professional to monitor symptom control. Take montelukast consistently, even on days without symptoms. Do not stop any prescribed controller or inhaler therapy unless told to do so by your prescriber.

If you have asthma, ask your clinician for a written action plan describing what to do during an acute attack. Always have your rescue inhaler available. For urgent breathing problems, use your rescue inhaler and seek help as directed.

Because montelukast carries an FDA boxed warning for serious neuropsychiatric events, promptly report new or worsening behavior or mood changes, sleep disturbances, agitation, or suicidal thoughts. See details in Side Effects.

Possible Side Effects

Serious - call your clinician promptly

  • Suicidal thoughts, agitation, new or worsening mood or behavior changes, or trouble sleeping.
  • Breathing problems or wheezing that worsen rather than improve.
  • Yellowing of the skin or eyes.
  • Dark urine.
  • Unusual bleeding or bruising.
  • Allergic reactions such as rash, hives, or swelling of the face, lips, or tongue.
  • Painful lumps under the skin or other signs suggestive of vasculitis.
  • Sinus pain, facial swelling, or persistent severe sinus symptoms.
  • Flu-like symptoms that do not resolve.
  • Fever or signs of infection.
  • Numbness, tingling, or pain in the hands or feet.

Common - often mild

  • Headache.
  • Trouble sleeping or vivid dreams.
  • Stuffy or runny nose.
  • Cough.
  • Stomach upset or abdominal discomfort.
  • Drowsiness or fatigue.
  • Dizziness.

Seek emergency care for signs of a severe allergic reaction such as swelling of the throat or difficulty breathing.

Storage and Handling

  • Keep out of reach of children.
  • Store at room temperature, typically 59 to 86 F (15 to 30 C).
  • Protect from excessive moisture and light; keep tablets in the original container.
  • Do not use after the expiration date; discard according to local guidance or return to a take-back program.

Related and Alternative Medicines

If montelukast is not suitable or not effective enough, clinicians may consider the following options depending on your diagnosis and severity. Discuss risks, benefits, and costs, and compare with Prices in the USA.

  • Zafirlukast (Accolate) - another leukotriene receptor antagonist; taken twice daily; avoid with liver disease.
  • Zileuton (Zyflo, Zyflo CR) - 5-lipoxygenase inhibitor; requires liver enzyme monitoring.
  • Inhaled corticosteroids (ICS) - such as fluticasone, budesonide, beclomethasone; cornerstone for persistent asthma.
  • ICS/LABA combinations - fluticasone-salmeterol, budesonide-formoterol, mometasone-formoterol, fluticasone-vilanterol; for moderate to severe asthma.
  • Short-acting beta agonists (SABA) - albuterol inhalers for acute relief only.
  • Antihistamines and intranasal steroids - cetirizine, loratadine, fexofenadine; fluticasone or budesonide nasal sprays for allergic rhinitis.
  • Biologics for severe asthma - omalizumab, mepolizumab, benralizumab, dupilumab, tezepelumab; specialist-prescribed.

Typical Prices in the USA (approximate, without insurance)

Prices vary widely by pharmacy, brand vs generic, location, and available coupons. The ranges below are monthly estimates in USD to help you compare options mentioned in Alternatives:

  • Montelukast generic 10 mg, 30 tablets: about $8 to $40 with common coupons; some pharmacies may charge $15 to $60 retail.
  • Brand Singulair 10 mg, 30 tablets: often $200 to $350 if available; generics are far less expensive and commonly dispensed.
  • Zafirlukast 20 mg, 60 tablets: roughly $120 to $250.
  • Zileuton ER 600 mg, 120 tablets: frequently $500 to $1,000.
  • Inhaled corticosteroids (generic fluticasone or budesonide inhaler): about $30 to $100 per inhaler month.
  • ICS/LABA combinations (Advair, Symbicort, Breo, generics where available): around $150 to $350 per month.
  • Albuterol inhaler (generic): about $20 to $80 per inhaler.
  • Oral antihistamines (generic cetirizine, loratadine): approximately $5 to $25 per month.

Check discount programs and pharmacy price tools. Insurance copays can be lower than cash prices. For U.S. purchasing rules, read Legal Status and Regulations.