Durasal 4mg Capsule CR is used to relieve symptoms of asthma and chronic obstructive pulmonary diseases (COPD) such as coughing, wheezing, and breathlessness. It helps in relaxing the muscles of the air passages, thus widening it and making it easier to breathe. You can take Durasal 4mg Capsule CR with or without food. The dose will depend on your condition and how you respond to the medicine. Try to take it at the same time each day. It is important to keep taking this medicine until your doctor tells you not to. Use this medicine regularly to get the most benefit from it even if you feel well. This medicine is generally safe however it may cause tremors, headaches, palpitation, fast heart rate, and muscle cramps in some people. These are often not dangerous and should gradually improve as your body gets used to the medicine. There are other, rarer, side effects and you should call your doctor straight away if you get chest pain, a very bad headache, or very bad dizziness. Before using this medicine, you should tell your doctor if you have high blood pressure, an overactive thyroid gland, a history of heart problems, diabetes, or low levels of potassium in your blood to make sure it is safe. Also, make sure your doctor knows if you are pregnant or breastfeeding before taking this medicine. This medicine can make you feel dizzy or shaky so avoid driving, cycling, or using tools or machinery until you feel better. You should not smoke as it causes damage to your lungs and will make your condition worse.