Inhaled insulin (1):
- is available in the USA as a rapid acting insulin; studies in people with type 1 diabetes suggest rapid pharmacokinetics (1)
- pilot study found evidence that compared with injectable rapid-acting insulin, supplemental doses of inhaled insulin taken based on postprandial glucose levels may improve blood glucose management without additional hypoglycemia or weight gain (1)
- although results from a larger study are needed for confirmation
- Exubera, an inhaled form of rapid acting insulin developed by Pfizer, became the first inhaled insulin product to be marketed in 2006 (2)
- but poor sales led Pfizer to withdraw it in 2007
- Afrezza developed by Mannkind, that uses a different technology (technosphere) was approved by the FDA in 2014
- technosphere technology (2):
- contains recombinant human insulin dissolved with powder (fumaryl diketopiperazine)
- once inhaled, technosphere insulin is rapidly absorbed upon contact with lung surface
- inhalable insulin is delivered with a thumb size inhaler with a rather increased dosing flexibility
- both components, insulin and powder (fumaryl diketopiperazine) are almost completely cleared from the lungs of healthy individuals within 12 hours of inhalation. In contrast to Exubera (8-9%) only 0.3% of insulin of inhaled insulin remained in lungs after 12 hours
- FDA approved Afrezza with a caution (Risk Evaluation and Mitigation Strategy) for a communication plan to inform health care professionals about the serious risk of acute bronchospasm associated with Afrezza
Inhaled insulin is contraindicated in patients with
- chronic lung disease, such as asthma and chronic obstructive pulmonary disease
Inhaled insulin is not recommended in patients who smoke or who recently stopped smoking
A review noted (2):
- may develop an increase in serum antibody levels though not related to any significant clinical change
- acute bronchospasm in patients with asthma and COPD
- may cause hypoglycemia, cough and throat pain/irritation
- significant decrease in Diffusing Capacity of Lungs for Carbon Monoxide (DLCO) relative to subcutaneous insulin
- smoking appears to enhance insulin absorption
All patients require spirometry (forced expiratory volume in 1 s [FEV1]) testing to identify potential lung disease prior to and after starting inhaled insulin therapy
Reference:
- ADA. Pharmacologic Approaches to Glycemic Treatment: Standards of Medical Care in Diabetes 2021. Diabetes Care 2021;44(Suppl. 1):S111-S124
- Mohanty RR, Das S. Inhaled Insulin - Current Direction of Insulin Research. J Clin Diagn Res. 2017;11(4):OE01-OE02. doi:10.7860/JCDR/2017/23626.9732