Derihaler 2.5mg Respules belongs to a group of medicines called fast-acting bronchodilators or “relievers”. It’s used to treat the symptoms of asthma and chronic obstructive pulmonary diseases (COPD) such as coughing, wheezing, and breathlessness. Derihaler 2.5mg Respules is called "reliever" inhalers because they give you quick relief from breathing problems when you need it. In most cases, you will be given another inhaler to prevent your symptoms (a “preventer”) and you should use this regularly every day. Derihaler 2.5mg Respules works quickly and the effects can last several hours. You can use it at any time of day, but only use it when you notice symptoms, such as coughing, wheezing, shortness of breath, tightness in the chest or you know that you are going to do an activity that can cause breathlessness. When an asthma attack happens, you should take the number of puffs your doctor recommends. There are several types of inhaler devices so make sure you know how to use your inhaler correctly, otherwise, it may not work. Do not stop using this medicine unless your doctor tells you to. If you stop, your breathing problems could get worse. Derihaler 2.5mg Respules is generally safe and effective but may cause some common side effects which include tremors, headaches, and tachycardia. These side effects are not often dangerous and should gradually improve as your body gets used to this medicine. There are other rare, 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 Derihaler 2.5mg Respules, 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 breast-feeding before taking this medicine. This medicine can make you feel dizzy or shaky, therefore, do not drive, use tools, or machinery until you feel better. Avoid smoking as it causes damage to your lungs and will make your condition worse.