Do Nasal Steroids Increase Blood Sugar?

Dwd asked

Type 2 diabetic here relatively controlled, with severe allergies. Would there be any difference between Flonase and Rhinocort affecting blood sugar? I've tried steroid shots and they launch blood sugar into orbit.

Answer

Inhaled nasal steroids (also referred to as corticosteroids) are often recommended as a 'first-line' therapy for treating both seasonal and perennial alleges (i.e. allergic rhinitis) (1). Many studies have shown they are more effective than oral antihistamines for the majority of nasal symptoms.

Overall, nasal steroids are thought to have a fairly positive safety profile, but there are concerns, especially when you consider the fact that oral steroids are often associated with a variety of side effects such as hyperglycemia (i.e. high blood sugar), immunosuppression and growth suppression.

As you specifically are concerned with an increase in blood glucose, I will touch on that topic here.

What Are Nasal Steroids?

Nasal steroids are available both via prescription and over the counter for the treatment of allergies and associated symptoms. They include:

• Flonase (Fluticasone propionate)
• Rhinocort (Budesonide)
• Nasacort (Triamcinolone)
• Flonase Sensimist (Fluticasone furoate)
• Beconase (Beclomethasone)
• Qnasl (Beclomethasone)
• Omnaris (Ciclesonide)
• Zetonna (Ciclesonide)
• Nasonex (Mometasone)
• Patanase (Olopatadine)

Corticosteroids have potent anti-inflammatory effects and also affect a variety of cells in the body that are associated with an inflammatory and allergic response. These cells include mast cells (which release histamine), eosinophils, macrophages, and lymphocytes.

While nasal steroids can be used on an 'as-needed' basis for temporary relief, studies show that consistent use often results in significant improvements in overall symptoms.

Are Nasal Steroids Absorbed?

One of the key question regarding nasal steroids is whether or not they are absorbed in significant amounts and whether or not they can cause systemic side effects based on this absorption.

Overall, nasal steroids are not thought to be significantly absorbed and generally do not cause the systemic side effects associated with oral steroids. One study concluded the following:

"Concerns among some health care providers, caregivers, and patients about systemic AEs [Adverse Effects] with these agents [intranasal steroids] are not supported by evidence. Rather, robust clinical evidence demonstrates the safety and efficacy of the newer INCs [Intranasal Corticosteroids] for management of allergic rhinitis, rhinosinusitis, and nasal polyp[s]."

Most nasal steroids are dosed in small amounts and have very little systemic absorption, which is why they are thought to produce few systemic effects. In fact, the bioavailability (i.e. the fraction of administered dose that reaches systemic circulation) of many nasal steroids is less than 1%.

Some nasal steroids, however, such as budesonide (Rhinocort) and triamcinolone (Nasacort), are absorbed to a more significant extent. Below are a few nasal steroids and their associated bioavailability.

As seen in the chart above, some are clearly absorbed more extensively than others. However, even with drugs that have relatively high bioavailability, you also need to take into consideration the small doses used in the nasal sprays.

Budesonide is a good example as it is available in an oral form and intranasal form. The intranasal spray is 32 mcg per spray (that is 32 micrograms, which is 1/1000th of 1 mg). Orally, it is available in a 3 mg capsule or 3,000 micrograms. So even with the relatively high bioavailability compared to other nasal steroids, the dose delivered intra-nasally is but a fraction of an oral dose.

Nasal Steroids And Blood Sugar

The side profile of oral steroids in extensive, especially when taken long term. In terms of blood sugar, they can increase levels by:

• Promoting gluconeogenesis (glucose production in the liver).
• Reducing insulin sensitivity, decreasing glucose uptake into cells.

Nevertheless for nasal steroids, when taking into account the significantly different route of administration, doses used and bioavailability, they are not thought to cause significant side effects in most individuals.

In regard to blood sugar levels specifically, one study that looked at budesonide (Rhinocort) noted no suppression of cortisol and no increase in blood sugars. Another noted no significant systemic side effects whatsoever.

However, one study noted that while most intranasal steroids didn't increase blood sugar levels or A1c, triamcinolone did (from their results anyway):