Singulair (montelukast) can be prescribed to help patients taking it to prevent an attack of asthma and relieve the symptoms of allergies, such as runny nose and sneezing. It can be used by adults and children older than 12. This medicine is available in a 10 mg tablet, chewable tablets containing 4 or 4 mg of the active ingredient and oral granules containing 4 mg of the active ingredient. Singulair is not going to help you treat an asthma attack already in progress - you need to use some fast-acting medication that can be inhaled to stop such an attack. If you think this medicine is not working for you and you get asthma attacks - talk to your doctor but do not stop the treatment. Before you feel the full benefits of Singulair a few weeks may pass. Make sure you talk to your health care provider about any symptoms that seem bothersome to you. The following serious side effects need to be reported: suicidal thoughts, depression, anxiety, worsening asthma symptoms, mood or behavior changes, muscle weakness, skin rash, severe tingling, and numbness. The side effects mentioned are quite rare, but you still need to be aware of their possibility. In most cases you will get some mild side effects that are not likely to interfere with the success of your treatment or your lifestyle. The following mild side effects are possible: upset stomach, diarrhea, stuffy nose, mild rash, headache, heartburn, cough, nausea, fever, stomach pain, and tooth pain. The success of your treatment depends on how precisely you are following all the directions provided by your health care provider. Some symptoms do not represent side effects, rather than signs of something going wrong in your treatment. If you experience behavior changes, anxiety, depression, thoughts about suicide, and some other symptoms of this kind - make sure you call your doctor immediately, as those can mean your treatment plan needs to be revised as you are obviously not getting all the benefits of your treatment. Your dose may be changed occasionally to make sure you fell all the beneficial effects of Singulair. The symptoms of Singulair overdose are not known, but you will need to report the fact of taking more of this medicine anyway. It's important to let your doctor know if you are taking such medicines as phenobarbital or rifampin, as further adjustments of your dose may be necessary. It's recommended to avoid situations and factors that may trigger an allergic reaction - and you can always learn more from your health care provider. It's important to use this medicine as recommended and avoid skipping your doses or missing them. You will need to come up with some kind of system to make sure you remember to take each single dose of Singulair you are supposed to take. If you happened to miss a dose of Singulair anyway - you can take it as soon as you remember. However, you are not supposed to take it if it's almost time for another dose. In that case you will need to skip the dose missed. Missing your doses too often can make your treatment less efficient.