Myteka 4mg powder sachets contain the active ingredient montelukast, which is used to treat asthma and other respiratory conditions. Montelukast is a leukotriene receptor antagonist, which means it helps to block the action of leukotrienes, which are chemicals in the body that can cause inflammation and narrowing of the airways. Myteka is usually taken once daily and is available in a pack of 14 sachets. It is important to follow the instructions of your doctor or pharmacist when taking Myteka.