Budesonide and formoterol inhaler (Symbicort): uses and cautions

Symbicort Turbohaler is a dry-powder inhaler delivering budesonide and formoterol fumarate dihydrate. Budesonide reduces swelling in the airway lining. Formoterol relaxes the muscle around the airways, and unlike salbutamol it keeps working for hours, which is why one device can serve both prevention and relief. Similar products from other manufacturers include DuoResp Spiromax, Fobumix Easyhaler and WockAIR.

For asthma, the licence covers adults and adolescents from 12 years for regular treatment where a combination is appropriate, either after inadequate control on a steroid plus as-needed short-acting reliever or in people already well controlled on both components, and as reliever therapy in mild asthma. A lower strength exists for children from 6 to 11 years, and the product is not recommended below 6.

For COPD, it is licensed in adults of 18 and over with a forced expiratory volume in one second below 70 per cent of predicted (after a bronchodilator) and a history of exacerbations despite regular bronchodilator treatment. A clinician decides who fits that description after breathing tests.

In the maintenance approach, the inhaler is taken at fixed times, with a separate fast-acting bronchodilator kept for rescue. The product information describes 1 to 2 inhalations twice daily for adults and adolescents, with some adults needing up to 4 inhalations twice daily.

In maintenance and reliever therapy (MART), you take a small daily maintenance dose and extra inhalations when symptoms arise. The information describes a maintenance dose of 2 inhalations a day, one extra inhalation if needed and one more if symptoms persist after a few minutes, with no more than 6 on a single occasion. MART is particularly considered for people with poor control who often need a reliever, or with past attacks that required medical intervention. It is not recommended for children under 12. If someone needs frequent bronchodilation without a matching need for more steroid, an alternative reliever is advised.

In reliever-only use for mild asthma, 1 inhalation is taken as needed. Whichever pattern you have, written instructions from your prescriber and your personal asthma action plan come first.

It is a breath-driven powder device, so you do not need to coordinate a puff. Follow the leaflet for loading and a firm, deep breath in. The product information advises rinsing your mouth with water after the maintenance dose to lessen thrush, and, if thrush develops, after as-needed doses too. Oropharyngeal thrush usually responds to antifungal treatment without stopping the steroid.

The device is dry-powder and has no propellant. Keep it dry, replace the cap and check the dose indicator so you are not caught out empty.

Common effects are those of the two components: headache, tremor, palpitations and thrush in the mouth or throat. An overdose of formoterol would be expected to cause tremor, headache and palpitations, and in isolated cases a very fast heartbeat, raised blood sugar, low potassium, an abnormal heart rhythm, nausea and vomiting, so heavy overuse should never be ignored.

Seek urgent help for chest pain, a racing or irregular heartbeat that will not settle, worsening breathlessness or wheeze straight after a dose, swelling of the lips, tongue or throat, or signs of a serious infection. Long-term steroid effects such as adrenal suppression, cataract, glaucoma or reduced bone density are possible at high doses. Suspected side effects can be reported through the Yellow Card scheme.

Beta blockers, including those in eye drops, can weaken formoterol and should not be given with it unless there are compelling reasons. Strong CYP3A4 inhibitors raise budesonide levels; the product information names ketoconazole, itraconazole, voriconazole, posaconazole, clarithromycin, telithromycin, nefazodone and HIV protease inhibitors, and advises avoiding the combination or separating doses as far apart as possible.

Several medicines that can prolong the QTc interval, including quinidine, disopyramide, procainamide, phenothiazines and tricyclic antidepressants, add to arrhythmia risk. Monoamine oxidase inhibitors may provoke hypertensive reactions. Low potassium from formoterol is worsened by steroids, theophylline-type medicines and diuretics, and matters particularly for people taking digoxin.

The product information states that data on about 2,000 exposed pregnancies show no increased malformation risk from inhaled budesonide, but there are no adequate data on formoterol in pregnant women, so use is considered when benefit outweighs risk, at the lowest effective budesonide dose. Budesonide passes into breast milk but no effect on the suckling child is anticipated at therapeutic doses; whether formoterol passes is unknown. The medicine has no or negligible effect on driving and machinery.