Clindamycin vs. Azithromycin: Which is Better?
Dr. Gerardo Sison
Nearly everyone will contract a bacterial infection at some point or another, whether they experience an ear infection or a sinus infection, among others.
Broad spectrum antibiotics like clindamycin and azithromycin are often the first line of treatment for certain infections.
Although the medications are very similar in many ways, there are some slight differences in the types of side effects and drug interactions each antimicrobial medication will cause and what conditions the drugs are best suited to treating.
When it comes to clindamycin vs. azithromycin, which is better?
Clindamycin and azithromycin are two commonly prescribed prescription antibiotics that are used for the treatment of many different types of bacterial infections. They are considered broad spectrum bactericidals which can target a wide range of pathogens such as mycobacterium and streptococci. While clindamycin and azithromycin can be effective at treating bacterial infections such as soft tissue infections and even some respiratory tract infections, they should not be used to treat viral infectious diseases like the common cold, the flu, or COVID-19.
Clindamycin is the generic version of the lincosamide brand name drug Cleocin. It belongs to a class of drugs called macrolide antibiotics, which work by stopping protein synthesis by harmful bacteria that are essential for reproduction and survival.
Azithromycin is the generic version of Zithromax, a popular brand name antibiotic medication that is most often prescribed as a Zithromax Z-Pak. Like clindamycin, azithromycin belongs to the macrolide antibiotics class of drugs.
They are also good options to combat both gram-positive and gram-negative bacteria for those who are allergic to penicillin and cannot take common drugs such as amoxicillin.
Azithromycin and clindamycin are both used to treat bacterial infections in pediatric and adult applications, but they are used to treat slightly different types of infections.
The most common applications of azithromycin include:
- Community-acquired pneumonia (in patients aged 6 months and older) caused by bacteria including Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, or Streptococcus pneumoniae
- Urethritis and cervicitis due to Chlamydia trachomatis or Neisseria gonorrhoeae
- Acute ear infections (in patients aged 6 months and older) caused by Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae
- Uncomplicated skin/skin structure infections caused by bacteria including Staphylococcus aureus, Streptococcus pyogenes, or Streptococcus agalactiae
- Genital ulcer disease in men caused by Haemophilus ducreyi (chancroid)
- Acute bacterial exacerbations of chronic bronchitis caused by bacteria that include Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae
- Acute bacterial sinusitis caused by Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae
- Pharyngitis/tonsillitis caused by Streptococcus pyogenes in patients who cannot use first-line therapy treatments and are two years of age or older.
Clindamycin is used to treat a variety of bacterial infections, including:
- Blood infections
- Abdominal infections
- Infections of the female reproductive tract, such as vaginosis
- Skin infections
- Septicemia (blood poisoning)
- Lung infections
- Bone and joint infections
Clindamycin is also used off label for the treatment of anthrax and malaria, and dentists may prescribe the drug as a preventative treatment for endocarditis, an infection of the lining of the heart that can develop after a dental procedure.
While azithromycin and clindamycin are both used to treat bacterial infections, one drug may be more effective depending on the infection being treated and the bacteria causing the infection.
Both azithromycin and clindamycin are available in a variety of different forms. Azithromycin is available in the form of a tablet, powder for oral suspension, injection, and eye drops.
Azithromycin is usually taken as part of a Z-pak dosing regimen, which includes a set number of tablets that are taken over the course of five days. Clindamycin is available in many different forms, including a capsule, injection, vaginal suppository, vaginal cream, topical foam, topical gel, topical lotion, and topical solution.
The side effects caused by azithromycin and clindamycin are slightly different. While both drugs can cause gastrointestinal side effects, they can also cause other adverse effects.
Common side effects associated with azithromycin include:
- Diarrhea or loose stools
- Abdominal pain
Less common side effects of azithromycin include:
- Tongue discoloration
- Abnormal liver enzyme levels
Rare but serious side effects of azithromycin include:
- Steven-Johnson Syndrome
- Irregular heartbeat
- Kidney problems
- Serious allergic reactions
- Hearing loss
Common side effects that are attributed to the use of clindamycin include:
- Stomach pain
- Metallic or unpleasant taste in your mouth
Less common side effects:
- Decreased blood platelets
- Decreased white blood cell levels
- Yeast infections
Rare but serious side effects associated with clindamycin may include:
- Stevens-Johnson syndrome
- Allergic reactions
- Abnormal liver function tests
- Kidney problems
- Esophageal ulcers
Clindamycin and azithromycin have the potential to disrupt the normal balance of bacteria in the gastrointestinal tract, particularly in the colon. This can occur because antibiotics often kill the healthy bacteria in the body in addition to harmful bacteria. Certain bacteria that are known to cause inflammation of the colon, including Clostridium difficile, are particularly susceptible to disruption resulting from the use of antibiotics.
If you start to experience signs of pseudomembranous colitis, including diarrhea, abdominal pain, fever, and shock, during or after treatment with clindamycin or azithromycin, make sure to seek medical attention immediately.
This may not be a complete list of adverse events.
Compared to other prescription drugs, clindamycin and azithromycin are associated with a relatively low rate of drug interactions. Azithromycin is known to interact with aluminum or magnesium-based antacids, including over the counter heartburn treatments like Maalox and Mylanta.
When combined with these antacids, azithromycin may be less absorbed into the intestine, which makes the drug less effective and can contribute to the development of antibiotic resistance in certain bacteria. Clindamycin is known to interact with drugs that act on an enzyme called CYP3A4, which is the same enzyme used to metabolize clindamycin.
When taken with medications that induce CYP3A4 action, such as rifampin, clindamycin is rendered less effective and may not be able to adequately treat infection. When used with drugs that inhibit the action of CYP3A4, including ketoconazole, patients are more likely to experience side effects from clindamycin due to increased absorption of the drug.
This may not be a complete list of drug interactions.
Azithromycin should not be used to treat pneumonia in patients who have any of the following medical conditions:
- Cystic fibrosis
- Nosocomial (hospital-acquired) infections
- Known or suspected bacteremia (bacteria in the blood)
Additionally, azithromycin should not be used to treat patients who have compromised immune systems, are elderly or disabled, are hospitalized, or who have no spleen (asplenia).
Clindamycin has the potential to cause a severe allergic reaction in some people. Symptoms of a severe allergic reaction include hives or other serious skin reactions, difficulty breathing, and swelling of the lips, tongue, face, or throat. People who have had a previous allergic reaction to clindamycin should not use the medication, as another allergic reaction could be fatal.
People with any of the following medical conditions should speak to their doctor about their medical history and seek medical advice prior to using clindamycin:
- Gastrointestinal disease or inflammation
- Allergies to medications
- Severe liver disease or liver problems
- Pregnancy or breastfeeding
- Age over 65
Azithromycin and clindamycin are both sold primarily as generic drugs, but there are brand name forms of each medication available. Azithromycin and clindamycin are both low cost medications that are covered by nearly all healthcare insurance plans and are available for less than 20 dollars without insurance.
Pharmacy discount cards can provide savings for patients using either generic or brand name azithromycin or clindamycin to treat bacterial infections regardless of their insured status.
The relative effectiveness of clindamycin and azithromycin will vary depending on which type of bacterial infection is being treated. Unfortunately, both clindamycin and azithromycin are subject to a high degree of antibiotic resistance, which makes them less effective at treating certain types of infections.
One notable area of difference in the effectiveness of the two medications is in the treatment of acne vulgaris, a type of inflammatory skin disorder that occurs as a result of bacterial infection in the skin. Studies have shown that azithromycin is more effective at treating acne vulgaris than clindamycin, but it is also more likely to cause side effects on the skin.
Broad spectrum antibiotics like clindamycin and azithromycin can be used as antibacterials to treat a wide range of bacterial infections with varying degrees of effectiveness. The two drugs cause similar side effects at similar rates and are available at an affordable cost in their generic form. Patients who do not have access to commercial insurance can save money on the cost of their prescription by using a pharmacy discount card from USA Rx.