Duloxetine’s Effect on Blood Glucose Levels

By: Neal Shah, Co-Editor-in-Chief

–

Duloxetine is a serotonin (5HT) and norepinephrine (NE) reuptake inhibitor (SNRI) introduced to the US market in 2004, indicated for the treatment of diabetic neuropathic pain.¹ A chemical figure of duloxetine is shown [in the PDF].²

It was developed in an effort to mimic tricyclic antidepressant mitigation of neuropathic pain without the extensive systemic side effects that limit their use.¹ Though duloxetine has not been shown to have any true neuroprotective effects, its combined SNRI effects contribute to pain cessation along the pain tracts in the central nervous system.¹ An interesting finding during trials was that duloxetine apparently slightly worsened both glucose control and raised hemoglobin A1c (HbA_1c), a marker of average blood glucose over a three-month period.¹ The package insert reports an average glucose increase of 12 mg/dL and an increase of HbA1c by 0.5% compared to placebo in a 41 week study.³ A division of Novartis found in a meta-analysis of seven trials that while impairment of glucose control was significant, at the end of a 52 week trial, changes in plasma glucose and A1c were statistically insignificant.⁴ Another meta-analysis done by Abbott laboratories found that these changes indicated no enhanced disease progression.⁵

In conclusion, when counseling a diabetic patient about the effects of duloxetine, inform them that they may see a slight increase in their blood glucose and/or A1c, and that the benefits of possible neuropathic pain relief may outweigh this slight increase.

SOURCES:

1. Smith T and Nicholson R. Review of duloxetine in the management of diabetic peripheral neuropathic pain. Vasc Health Risk Manag. 2007 December; 3(6): 833—44.
2. Duloxetine – Compound Summary. Available at: http://pubchem.ncbi.nlm.nih.gov/sumary/summary.cgi?cid=60835. Accessed 15 September 2012.
3. Eli Lilly and Company. Cymbalta (duloxetine) package insert. Accessed 8 September 2012.
4. Crucitti A, Zhang Q, Nilsson M et al. Duloxetine treatment and glycemic controls in patients with diagnoses other than diabetic peripheral neuropathic pain: a meta-analysis. Curr Med Res Opin. 2010 Nov;26(11):2579—88. Epub 2010 Sep 27.
5. Hall JA, Wang F, Oakes TM et al. Safety and tolerability of duloxetine in the acute management of diabetic peripheral neuropathic pain: analysis of pooled data from three placebo-controlled clinical trials. Expert Opin Drug Saf. 2010 Jul;9(4):525—37.