Seretide is a Prescription Medicine for the treatment of reversible obstructive airway disease (ROAD) including asthma, and for the treatment of chronic obstructive pulmonary disease (COPD). Seretide 250/25 microgram inhaler is a private purchase medicine that you will need to pay for. Use strictly as directed. Seretide is not for relief of acute symptoms. Always carry your reliever inhaler. Do not discontinue Seretide abruptly. Tell your doctor: If you are taking any other medicines or herbal remedies, you have pulmonary tuberculosis (TB), a thyroid problem or a heart problem, or you are having treatment for high blood pressure. Side Effects may include: Headache, 'shaky' feeling, fast heart rate, irritation in the nose and throat.