Medically Reviewed on 8/22/2023

Generic Name: solithromycin

Brand Name: Solithera

Drug Class: Ketolide Antibiotics

What is solithromycin, and what is it used for?

Solithromycin is a novel antibiotic being developed to treat community-acquired bacterial pneumonia (CABP), a major cause of severe lung infection, life-threatening disease, and death, the world over. Solithromycin is a ketolide antibiotic that belongs to a novel class of macrolide antibiotics specifically designed to act against respiratory tract bacteria that have become resistant to treatment with macrolide class of antibiotics. Studies show solithromycin inhibits bacteria (bacteriostatic) as well as kills them (bactericidal).

Solithromycin is a fourth generation fluoroketolide antibiotic derived from erythromycin, a macrolide antibiotic, but more potent than macrolide antibiotics. Solithromycin works similar to macrolides, by preventing the synthesis of proteins that bacteria require to survive and grow. Solithromycin binds to 23S rRNA and 50S subunits in the bacterial ribosomes, cellular particles that synthesize proteins, and prevents the formation of peptide chains. Solithromycin also interacts with a third site C-2 fluorine of the bacterial ribosome.

Solithromycin is effective against the common bacteria that cause CABP, including those resistant to macrolide, fluoroquinolone and penicillin antibiotics. Solithromycin is not approved by the FDA yet and is currently in clinical trials to evaluate its safety profile and possibility of serious liver injury. In addition to CABP, solithromycin is also being investigated for use in other infections including uncomplicated urogenital urethritis, uncomplicated gonorrhea, Mycoplasma genitalium infections and bacterial infections in pregnancy.

Organisms causing CABP that are susceptible to solithromycin include:


  • Solithromycin is in clinical trials and limited information is available on the drug’s contraindications, warnings and precautions.
  • Liver enzymes ALT and AST have been elevated in clinical trials and solithromycin is being further studied for potential liver injury.
  • Intravenous solithromycin can cause infusion-related reactions.
  • Some patients experienced the following during clinical trials:

What are the side effects of solithromycin?

Common side effects of solithromycin include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

  • Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
  • Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
  • Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
  • Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.


MRSA describes a specific type of bacteria that are resistant to certain antibiotics. See Answer

What are the dosages of solithromycin?


  • 200 mg


  • 400 mg


Community-Acquired Bacterial Pneumonia

  • The recommended dose of solithromycin capsules is 800 mg orally once on day 1, followed by 400 mg orally once daily on days 2-5.
  • The recommended dose of solithromycin for injection is 400 mg intravenously (IV) once a day for 7 days; when switching to oral solithromycin, the applicant proposes a loading dose of 800 mg orally, followed by 400 mg orally daily to complete the 7-day course.


  • Solithromycin is an investigational drug and there is no information available on overdose symptoms or treatment. Solithromycin overdose is likely to be toxic to the liver.

What drugs interact with solithromycin?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

Solithromycin may interact with:

  • CYP3A/P-gp inducers
  • CYP3A substrates
  • P-gp substrates

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

Pregnancy and breastfeeding

  • Solithromycin is an investigational drug and no information is available on its use during pregnancy and breastfeeding.

What else should I know about solithromycin?

  • Solithromycin is in clinical trials, not yet approved by the FDA and is not available commercially.


Solithromycin is a novel antibiotic being developed to treat community-acquired bacterial pneumonia (CABP), a major cause of severe lung infection, life-threatening disease, and death, the world over. Common side effects of solithromycin include diarrhea, headache, nausea, dizziness, pneumonia, elevation of liver enzymes ALT and AST, infusion site reactions, blurred vision, tired eyes, loss of consciousness (syncope), and low muscle tone (hypotonia).

Treatment & Diagnosis

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Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 8/22/2023