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.
Nodules are inflamed, painful, deep bumps under the skin.Comedones that are 1 mm or larger are called macrocomedones. They are closed comedones and are more frequent on the face than neck.Solar comedones (sometimes called senile comedones) are related to many years of exposure to the sun, usually on the cheeks, not to acne-related pathophysiology. Management
Using nonoily cleansers and mild soap may not cause as much irritation to the skin as regular soap. Blackheads can be removed across an area with commercially available pore-cleansing strips (which can still damage the skin by leaving the pores wide open and ripping excess skin) or the more aggressive cyanoacrylate method used by dermatologists.Squeezing blackheads and whiteheads can remove them, but  can also damage the skin. Doing so increases the risk of causing or transmitting infection and scarring, as well as potentially pushing any infection deeper into the skin. Comedo extractors are used with careful hygiene in beauty salons and by dermatologists, usually after using steam or warm water.Complementary medicine options for acne in general have not been shown to be effective in trials. These include aloe vera, pyridoxine (vitamin B6), fruit-derived acids, kampo (Japanese herbal medicine), ayurvedic herbal treatments, and acupuncture.Some acne treatments target infection specifically, but some treatments are aimed at the formation of comedones, as well. Others remove the dead layers of the skin and may help clear blocked pores.Dermatologists can often extract open comedones with minimal skin trauma, but closed comedones are more difficult.