People with diabetes need to observe special precautions when taking medications because some of these may alter their blood sugar level. There are medications that can increase blood sugar levels while others may decrease the glycemic control at an alarming rate.
Antibiotics are one of the most notorious medications that may result in undesired blood sugar level changes in anyone with Type 2 diabetes using oral hypoglycemic medications. However, negative drug interactions are rarely seen in diabetics who use insulin to control their blood sugar level.
What are the usual concerns noted with antimicrobial therapy and oral hypoglycemic agents?
- severely ill patients and elderly individuals are more prone to an alteration in their glycemic control compared to patients in the younger age group, and those who feel apparently well despite their infectious disease.
- people suffering from diabetes and tuberculosis at the same time have a higher treatment failure compared to non-diabetics. This is due to a decreased serum concentration of rifampicin in people with diabetes, particularly those who are having problems with their weight as well.
- treatment failure with may also occur in obese people with diabetes if the dosage is not computed based on their weight.
What can potentially delay the diagnosis of a potential drug interaction?
Severely ill patients that have systemic complications may have hypoglycemia or hyperglycemia, and this may result in the added difficulty in the diagnosis of a possible drug interaction.
What are the most common antibiotics that can alter your blood sugar level?
- such as gatifloxacin, levofloxacin, ciprofloxacin and moxifloxacin, may result in both hypoglycemia and hyperglycemia in certain patients and, in most cases, the alteration in blood sugar level is dose dependent.
- may enhance the release of insulin from the pancreas thereby decreasing the blood sugar level.
Among the fluoroquinolones, gatifloxacin has the most prominent effect on the blood sugar level. The next in line is levofloxacin, so it may be unsuitable for diabetics who have unstable blood sugar and those who are severely ill. Ciprofloxacin may have the least effect on blood sugar control; therefore it can be used safely for people with diabetes.
2. Macrolides (azythromycin, erythromycin, and clarithromycin):
- clarithromycin, a type of macrolide, can increase the effect of repaglinide, causing an excessive decrease in the blood sugar level. To prevent this from happening, the replaglinide dosage must be adjusted when using clarithromycin.
- macrolides may also increase the serum concentration of sulfonylureas, another type of oral hypoglycemic agent. Doctors should always consider decreasing the sulfonylurea dosage when also prescribing a macrolide.
- rifampicin may significantly decrease the effect of some oral hypoglycemic agents such as nateglinide, rosiglitazone, pioglitasone, sulfonylureas and repaglinide, resulting in a decreased effect of the said drugs. Therefore, when rifampicin is used in diabetics with tuberculosis, a higher dose of anti-diabetic medication may be necessary.
- an increased blood concentration of metformin can be noticed with the intake of cephalexin. However, the clinical significance of this problem is still unknown.
If you are given a new medication and suddenly find your blood sugar is significantly higher or lower than usual, ask your doctor to check for the possibility the new medication has a definite glucose-lowering or glucose-raising effect.