Dr.Jothydev Kesavadev
Dr.Shabeer A Rasheed
Gatifloxacin, a commonly prescribed anti microbial can produce profound hypoglycemia and disturbances in glucose homeostasis especially in diabetes patients on sulphonylureas. Also new onset disturbances in glucose homeostasis can occur in patients who were unaffected by the previous use of gatifloxacin. Therefore it is suggested that gatifloxacin is better avoided in patients with diabetes and in the elderly.
Gatifloxacin, an 8 methoxy fluoroquinolone is a commonly prescribed anti-microbial by the general practitioners and physicians for the treatment of various respiratory tract infections The total bacterial cure rate and eradication rate of gatifloxacin in clinical studies are 91.1% and 93.3% respectively (1) . Gatifloxacin is considered to be a relatively safe drug without too much adverse effect. However there are reports of gatifloxacin induced hypoglycemia and hyperglycemia in diabetic as well as non-diabetic patients (2, 3) .
Here we report 3 cases of severe hypoglycemia followed by severe and persistent hyperglycemia induced by gatifloxacin in diabetic patients who were previously metabolically stable with glimepiride and metformin.
1. in 2003: A 55-year-old lady, known asthmatic for 25 years and diabetic for 4 years has been on regular follow up in our clinic since last 3 years. Her usual medications include a combination of inhalation salmeterol 25mcg + fluticasone 125mcg BD, inhalation tiatropium bromide 18mcg OD, a fixed drug combination of glimepiride1 mg +metformin500mg BD and atorvastatin 10 mg OD. She was under intensive metabolic management with regular home glucose monitoring and her HbA1C values of the past one-year ranged between 6.5-7%.
Few days back she visited our clinic with complaints of mild fever and productive cough for one week. She was put on oral gatifloxacin 200 mg BD for 5 days along with her usual medications. Her inhaled medicines for asthma were also modified. Next day early morning at around 2.00 am, her husband was awakened to realize that she was in a state of discomfort with profound sweating and not responding to verbal commands. As the couple was well educated on the clinical features of hypoglycemia, her blood glucose was immediately estimated and found to be 32mg%. She was rushed to a near by doctor who administered intra venous betamethasone 4 cc and 25% dextrose 10 cc. She became conscious soon and when the blood glucose was measured again it was found to be 60mg%. She continued her full course of gatifloxacin therapy without any similar attacks of hypoglycemia.
The patient did not report back to our clinic until when she noticed that her blood glucose values were abnormality high during the days of gatifloxacin therapy. Two-hour post meal glucose values on the next 4 days were found to be 316 mg%, 423mg%, 508mg% and 446mg% respectively. However without any further modification of anti-diabetic therapy, her blood glucose values touched normal within 2-3 days after completion of gatifloxacin therapy.
2.In 2005: Gatifloxacin prescribed by a dentist for our patient after dental extraction. She was 53 yrs under good diabetes control.She fainted the next day in her office and was taken to the hospital. Her blood sugar was found to be 35mg%.She too survived.
3.In 2005: A 53 y.o lady under our care for diabetes. Gatifloxacin was prescribed by a dermatologist for her skin infection. She developed fatal hypoglycemia the next day. Immediately called us over the telephone and we realized the situation. She is now doing well.
Discussion
The exact etiology of gatifloxacin interaction to produce glucose disturbances is not yet clear. Certain studies describe that gatiflloxacin can stimulate insulin secretion by inhibiting potassium dependent ATP channels which may the reason for hypoglycemia (4) . Moreover data from certain other studies reveals that unlike levofloxacin, gatifloxacin is found to reduce both blood glucose and plasma insulin levels in a dose dependent manner in experimental animals (5) . Gatifloxacin is renally excreted and high serum concentration will remain in the elderly due to age related decline in renal function (4) . In animal studies the propensity of gatifloxacin for insulin release was related to its high serum concentration. . Hence, we suggest gatifloxacin is better avoided not only in patients with diabetes but also in all elderly individuals .
Dr.Jothydev's Diabetes Center, Trivandrum |
