My daughter was diagnosed with a sinus infection three days ago. She was having highs quite frequently with no obvious reason before we took her in. She typically does not have a lot of highs. She was prescribed Cefdinir, 300 milligram suspension, 6 ml twice a day for 10 days. After two full days of doses, her blood sugar has been 200 to 300 mg/dl [11.1 to 16.7 mmol/L] consistently. We lowered her insulin to carbohydrate ratio from 1:20 to 1:15 for the time being. Should we be dosing insulin for the antibiotic? At her last clinic visit, her A1c was 6.3, down from 11.4 at diagnosis. Her urine has been negative for ketones.

It is not a problem with antibiotics but with the underlying infection. This often produces what is called insulin resistance and thus the need for higher insulin doses on “sick days” to bring the hyperglycemic values downward. Most of us recommend about a 10 to 20% increase in dose based on 24 hour insulin dose usually taken. This is then added to the bolus at meals. If on a pump, then it may require a boost in basal dose, too. All such decisions should be made according to positive or negative ketones; moderate to large ketones would suggest using the 20% booster rule while negative to small ketones, using the 10% booster. This is usually needed for several days but very variable depending on the actual illness, severity, etc. The antibiotics should start to clear the infection within two to four days but only if bacterial; if viral, then antibiotics don’t work and the illness just must run its course. Following the sugar and ketone levels and the sick days rules should work. If weight loss, persistence of the hyeperglycemia, please give your diabetes team a call for more specific advice.

SB

[Editor’s comment: Some general sick day guidelines are available in Dr. Peter Chase’s Understanding Diabetes. If you do not have a sick days plan from your own endocrinologist, please ask for one.

BH]