Medicine
Fact-checked

At TheHealthBoard, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What Are Macrolides?

Clara Kedrek
Clara Kedrek

Macrolides are a class of medications that have a macrolide ring as part of their chemical structure; this ring structure is what gives the drugs their chemical activity. These pharmaceuticals are used either to treat bacterial infections or to decrease the activity of the body’s immune system. Although medications in this class can have a number of side effects, they are commonly prescribed because the good they do outweighs their possible adverse effects.

Many macrolides are used as antibiotic medications, and fight infection by inhibiting the ability of bacteria to make proteins. Examples of antibiotic macrolides include clarithromycin, erythromycin, and azithromycin. Without their protein-producing capability, bacteria are not able to reproduce. As a result, bacteria levels are stabilized, and eventually decrease with continued antibiotic use. The clinical symptoms associated with the bacterial infection decrease as the bacteria die off.

Urinary tract infections may be treated with macrolides.
Urinary tract infections may be treated with macrolides.

A number of bacterial infections can be treated with macrolides. They are commonly used to treat respiratory tract infections such as pneumonia, bronchitis, and sinusitis. Many genitourinary infections such as pelvic inflammatory disease, chlamydia, and urinary tract infections also respond well to these antibiotics. Other uses include treating traveler’s diarrhea and skin infections.

Macrolides can be used to treat a variety of autoimmune diseases, such as ulcerative colitis.
Macrolides can be used to treat a variety of autoimmune diseases, such as ulcerative colitis.

Side effects caused by the macrolide antibiotics are typically mild, but can include diarrhea, nausea, rash, and headache. Patients with myasthenia gravis, low blood potassium, or renal impairment should use caution in taking these medications, as they could experience more severe side effects. These antibiotic medications are only available by prescription in the United States.

Bacterial infections such as pelvic inflammatory disease can be treated with macrolides.
Bacterial infections such as pelvic inflammatory disease can be treated with macrolides.

Another use for macrolides are as immunosuppressive agents. The mechanism of action of these medications differs from how the antibiotic macrolides work. Immunosuppresive macrolides inhibit the activation of T cells, which are a type of white blood cell important in protecting the body from harm. Decreased T cell activity results in suppression of the immune system. The non-antibiotic macrolides include tacrolimus, pimecrolimus, and sirolimus.

Macrolide antibiotics can cause negative side effects in some patients.
Macrolide antibiotics can cause negative side effects in some patients.

The immunosuppressive macrolides are important in treating a number of conditions. One use of these drugs is to suppress the immune system of patients receiving organ transplants. Without immunosuppressive agents, the recipient’s immune system could reject the transplanted organ. Another use of the medications is to treat a variety of autoimmune diseases such as ulcerative colitis and psoriasis. In these conditions, the immune system is attacking the body, and suppressing the action of the immune system results in decreased symptoms.

Macrolides are commonly used to treat respiratory tract infections.
Macrolides are commonly used to treat respiratory tract infections.

Adverse reactions from these immunosuppressive agents are typically more severe compared to their antibiotic counterparts. They can decrease blood counts, increase the risk for infection, and cause cardiac arrhythmias. Often these drugs are only prescribed by specialists such as rheumatologists or physicians trained in transplant medication.

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • Urinary tract infections may be treated with macrolides.
      By: joshya
      Urinary tract infections may be treated with macrolides.
    • Macrolides can be used to treat a variety of autoimmune diseases, such as ulcerative colitis.
      By: inesbazdar
      Macrolides can be used to treat a variety of autoimmune diseases, such as ulcerative colitis.
    • Bacterial infections such as pelvic inflammatory disease can be treated with macrolides.
      By: joshya
      Bacterial infections such as pelvic inflammatory disease can be treated with macrolides.
    • Macrolide antibiotics can cause negative side effects in some patients.
      By: Alliance
      Macrolide antibiotics can cause negative side effects in some patients.
    • Macrolides are commonly used to treat respiratory tract infections.
      By: joshya
      Macrolides are commonly used to treat respiratory tract infections.
    • Macrolides may be used to treat psoriasis.
      By: hriana
      Macrolides may be used to treat psoriasis.
    • Side effects caused by macrolide antibiotics may include headache.
      By: Piotr Marcinski
      Side effects caused by macrolide antibiotics may include headache.
    • Infections like pneumonia may be treated with macrolides.
      By: designua
      Infections like pneumonia may be treated with macrolides.
    • Macrolides may be used to treat bronchitis.
      By: Photographee.eu
      Macrolides may be used to treat bronchitis.