What Is Aztreonam Injection Used For?
Aztreonam injection is primarily used for the treatment of certain bacterial infections, such as of the lungs, abdomen (stomach), and urinary tract. However, healthcare providers may also recommend the drug for "off-label" uses. These unapproved uses can include the treatment of gonorrhea, musculoskeletal infections, and bacterial meningitis. This medicine is approved for use in adults and children as young as nine months old.
Aztreonam injection (Azactam®) is a prescription antibiotic approved to treat a variety of infections caused by several different types of bacteria. This medication is given as an injection into a vein (an intravenous, or IV, injection) or a muscle (an intramuscular, or IM, injection). Aztreonam injection was the first medicine in a class of antibiotics known as monobactams.
The types of infections aztreonam injection may be used to treat include:
- Urinary tract infections (UTIs), including infections of the kidneys or the bladder
- Lower respiratory tract infections, such as pneumonia or bronchitis
- Blood infections (septicemia)
- Skin and skin structure infections, including infections caused by burns
- Intra-abdominal infections (infections that occur within the abdomen, or stomach area), such as peritonitis, an infection of the inner lining of the abdomen
- Infections of the reproductive tract, such as infections of the lining of the uterus (endometritis)
- Infections occurring after surgery, including abscesses and skin infections.
Many different types of bacteria can cause the above infections. However, not all bacteria are susceptible to aztreonam injection. Therefore, the medication is only used to treat the above infections when they are caused by certain bacteria. More specifically, aztreonam injection is only useful for treating infections caused by a group of bacteria known as Gram-negative bacteria.
Most bacteria are categorized into one of two groups: Gram-positive or Gram-negative. These categories are based on how the bacteria appear under a microscope after a process known as Gram staining. During Gram staining, bacteria are stained with a dye known as crystal violet, washed off, and then stained with a paler-colored dye.
Differences in the bacteria's cell membrane (the outer protective layers of the cell) determine which stain they retain. Gram-positive bacteria have a thick cell wall that allows them to retain the purple color of the crystal violet dye. Gram-negative bacteria, on the other hand, lose the purple color and take on the pinkish appearance of the paler dye.
Gram-negative bacteria have an additional outer membrane protecting the cell. This helps make them generally less susceptible to antibiotics than gram-positive bacteria. Aztreonam injection is not effective against all Gram-negative organisms. Examples of gram-negative bacteria that aztreonam injection may be active against include:
- Escherichia coli (E. coli)
- Pseudomonas aeruginosa
- Haemophilus influenzae
- Proteus mirabilis
Aztreonam injection should only be used to treat infections that are known to be or strongly suspected to be caused by bacteria that are susceptible to the drug. In many cases, your healthcare provider will order certain tests to determine what type of bacteria is causing your infection and whether the bacteria is expected to respond to aztreonam injection. Your healthcare provider may choose to start you on more than one antibiotic before the results of the tests are known, especially if you have a serious infection that could be caused by any of several different bacteria.
Aztreonam injection is completely ineffective for treating infections caused by viruses, such as the common cold or the flu. It should therefore not be used to treat viral illnesses. Using this medication to treat viral infections or infections caused by bacteria that do not respond to aztreonam injection could lead to the development of bacteria that are resistant to aztreonam injection and other antibiotics.