english.prescrire.org > Spotlight > Archives : 2006 > Inhaled insulin: no proven benefits and too many unknowns concerning risks

Spotlight: Archives

Every month, the subjects in Prescrire’s Spotlight.

2006 : 1 | 30 | 60

Inhaled insulin: no proven benefits and too many unknowns concerning risks

Subcutaneous injection remains the standard way of administering insulin to diabetics.

The standard treatment for type 1 diabetes (also known as insulin-dependent diabetes) is the daily administration of at least 3 subcutaneous injections of insulin. Subcutaneous insulin is sometimes also helpful in patients with type 2 diabetes, who are generally treated with oral medication.

Inhaled human insulin will soon come onto the French market. A 1 mg dose of inhaled insulin has a similar effect to the injection of around 3 units of subcutaneous insulin. The available results of trials for type 1 diabetes show that three inhalations combined with a subcutaneous injection are no more effective in controlling glycaemia than two injections. The most pertinent comparisons have not been carried out for type 2 diabetes.

Inhaled insulin causes impairment of some respiratory functions and the frequent appearance of antibodies; these are worrying effects whose long-term consequences are still unknown. The absorption of inhaled insulin is notably affected by passive or active smoking. This pharmaceutical form, which is very sensitive to moisture, is relatively complicated to use and does not allow a precise adjustment of the insulin dose.

It is not justifiable to expose patients to a risk of severe adverse effects solely for a possible gain in convenience. It is better to keep to subcutaneous injections, which have been more thoroughly evaluated and make it possible to adjust the dose more accurately.

©Prescrire September 2006

Source: "Insuline humaine pour inhalation-Exubera°. Pas de bénéfice à court terme, trop d'inconnues à long terme" Rev Prescrire 2006 ; 26 (275) : 565.

- More articles in Prescrire's "Spotlight"...