As long as the pancreatic beta cells are able to sense the glucose level and produce insulin, the amount of insulin secreted is usually the amount required to maintain a fasting blood glucose between 70 and 100 mg/dL (3.9–5.6 mmol/L) and a non-fasting glucose level below 140 mg/dL (<7.8 mmol/L).When liver cells and other cells that remove glucose from the blood become less sensitive (more resistant) to the insulin, the pancreas increases secretion and the level of insulin in the blood rises. This increased secretion can compensate for reduced sensitivity for many years, with maintenance of normal glucose levels. However, if insulin resistance worsens or insulin secretion ability declines, the glucose levels will begin to rise. Persistent elevation of glucose levels is termed diabetes mellitus.Typical fasting insulin levels found in this type of hyperinsulinism are above 20 μU/mL. When resistance is severe, levels can exceed 100 μU/mL.In addition to being a risk factor for type 2 diabetes, hyperinsulinism due to insulin resistance may increase blood pressure and contribute to hypertension by direct action on vascular endothelial cells (the cells lining blood vessels). Hyperinsulinism has also been implicated as a contributing factor in the excessive production of androgens in polycystic ovary syndrome.The principal treatments of hyperinsulinism due to insulin resistance are measures that improve insulin sensitivity, such as weight loss, physical exercise, and drugs such as thiazolidinediones or metformin. Inappropriate secretion, associated with hypoglycemia
Hyperinsulinism may also refer to forms of hypoglycemia caused by excessive insulin secretion.
It has no useful activity against Gram-positive bacteria or anaerobes. It is known to be effective against a wide range of bacteria including Citrobacter, Enterobacter, E. coli, Haemophilus, Klebsiella, Proteus, and Serratia species. The following represents minimum inhibitory concentration (MIC) susceptibility data for a few medically significant microorganisms. Staphylococcus aureus 8 - >128 μg/ml
Staphylococcus epidermidis 8 - 32 μg/ml
Streptococcus pyogenes 8 - ≥128 μg/mlSynergism between aztreonam and arbekacin or tobramycin against P. aeruginosa has been suggested. Spectrum of activity
Acinetobacter anitratus, Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis are generally susceptible to aztreonam, while some staphylococci, Staphylococcus aureus, Staphylococcus haemolyticus and Xanthomonas maltophilia are resistant to it. Furthermore, Aeromonas hydrophila, Citrobacter koseri (Citrobacter diversus), Pantoea agglomerans (Enterobacter agglomerans), Haemophilus spp. and Streptococcus pyogenes have developed resistance to aztreonam to varying degrees.Aztreonam can be safely used in patients with a penicillin or cephalosporin allergy (except for patients with a ceftazidime allergy as ceftazidime and aztreonam share a similar side chain). It is also frequently used as an alternative to aminoglycosides because is not ototoxic or nephrotoxic.Aztreonam use has been recently reconsidered for human infections sustained by metallo-beta-lactamase (MBL)-producing Gram-negative bacteria. In these circumstances aztreonam is combined with avibactam (ceftazidime/avibactam). The combination of aztreonam and avibactam has demonstrated to be active against 80% of MBL isolates reaching a clinical infection resolution in 80% of MBL-infected patients. Administration
Aztreonam is poorly absorbed when given orally, so it must be administered as an intravenous or intramuscular injection (trade name Azactam), or inhaled (trade name Cayston) using an ultrasonic nebulizer.