Azithromycin
antibiotic · macrolide
Third-party optionBy the Layer Nutrition editorial team
What this medicine is for
Azithromycine est un médicament de la catégorie « antibiotique (macrolide) ». Les antibiotiques traitent les infections dues à des bactéries. Ils se prennent en cure, sur une durée définie, jusqu'au bout de la prescription.
Dans le cas d'Azithromycine, cela se traduit ainsi : Traite une infection bactérienne. Il s'emploie plutôt de façon ponctuelle ou en cure courte, le temps de passer un épisode.
Under which brands it is found
Azithromycine entre dans la composition d'environ 17 présentations recensées en France. On la trouve sous plusieurs noms de marque et en génériques.
- Azadose
- Azithromycine Arrow Lab
- Azithromycine Bgr
- Azithromycine Cristers Pharma
- Azithromycine Eg
- Azithromycine Krka
- Azithromycine Monodose Sandoz
- Azithromycine Pfizer
- and other presentations
Generics and the original brand are equivalent for the active substance; only the appearance, the name or the excipients may differ.
On the plate: potassium and magnesium
Azithromycin can prolong the heart's QT interval. An uncorrected lack of potassium or magnesium promotes this rhythm disturbance. Food helps keep these two minerals at a good level during treatment, and it is the simplest lever to maintain day after day.
Potassium is concentrated in fruits and vegetables: dried apricots, potato, sweet potato, spinach, lentils, beans, banana, avocado, tomato, orange and salmon. Spreading these foods across the day's meals covers a good share of your needs.
Magnesium comes mainly from almonds, pumpkin seeds, spinach, black beans, brown rice, oats, dark chocolate, banana and salmon. Several of these foods provide both minerals at once, such as spinach, beans and banana. You add them to your meals on top of your treatment, never in its place.
How azithromycin works
Azithromycin belongs to the macrolide family. It binds to the 23S portion of the bacterium's 50S ribosomal subunit, the machinery that builds its proteins. By attaching there, it blocks the passage of aminoacyl-tRNA and the elongation of the peptide chain, which halts bacterial protein synthesis. Its action is mainly bacteriostatic: it prevents bacteria from multiplying, and becomes bactericidal at high doses against certain germs.
This target is specific to bacteria. Azithromycin has no effect on viruses: it treats neither the common cold, nor influenza, nor other viral infections. That is why a doctor reserves it for confirmed or strongly suspected bacterial infections.
Why it is prescribed
Azithromycin is used to treat a wide range of bacterial infections. It is prescribed for community-acquired pneumonia, middle ear infection, pharyngitis, skin infections and exacerbations of chronic obstructive pulmonary disease. It is also used in several sexually transmitted infections: chlamydia, gonococcus and Mycoplasma genitalium.
It also covers more specific situations, such as Mycobacterium avium infections in patients with AIDS. The choice of the drug and the duration depend on the targeted germ and the site of the infection, which the doctor determines on a case-by-case basis.
A long half-life, short courses
Azithromycin has a striking pharmacological feature: its mean terminal half-life is around 68 hours. This slow elimination allows short courses and a single daily dose, with the drug's effect continuing long after each dose. Its oral bioavailability is about 38 percent, and it is eliminated mainly through the bile.
It concentrates strongly inside cells, particularly phagocytes, with an intracellular to extracellular concentration ratio greater than 30 after one hour. It thus reaches higher concentrations in tissues than in plasma, closest to the sites of infection. This tissue accumulation partly explains the effectiveness of such brief treatments.
How to take it day to day
Azithromycin is taken once a day, with or without food, at a regular time. For the tablet, taking it with a meal increases the maximum concentration (Cmax) by 23 percent, without changing the total exposure (AUC). The usual adult regimen ranges from 250 to 500 mg per day for 3 to 5 days, or a single 1 g dose for a chlamydia infection.
Regularity of intake determines the treatment's effectiveness. You must complete the prescribed course, even if symptoms improve before the end, and not stop it on your own initiative. Antacids containing aluminum or magnesium should be taken separately from azithromycin, because they can interfere with its absorption.
The effects to know about
The most frequent adverse effects are digestive. In multiple-dose clinical trials in adults, diarrhea or loose stools are seen in 4 to 5 percent of people, nausea in 3 percent, abdominal pain in 2 to 3 percent, and vomiting in 1 percent or less. These disturbances are partly explained by the activation of motilin receptors, which stimulates intestinal motility.
Serious effects remain rare. There are reports of liver injury (hepatotoxicity), severe skin reactions such as Stevens-Johnson syndrome, and major allergic reactions (anaphylaxis). These situations call for stopping the treatment and seeking care without delay.
QT, interactions and monitoring
Like other macrolides, azithromycin can prolong the heart's QT interval, with rare cases of torsades de pointes, a serious rhythm disturbance. A lowered and uncorrected potassium or magnesium level is a pro-arrhythmic condition that raises this risk. Several interactions call for caution: the combination with pimozide is contraindicated, colchicine (a P-glycoprotein substrate) calls for vigilance, and monitoring is reinforced with nelfinavir.
In patients on warfarin, the prothrombin time (INR) is monitored, because the combination can alter its balance. Monitoring relies mainly on clinical observation: the courses are short and stopping for an adverse effect remains rare. Attention is paid to signs of liver injury, and the INR is checked in people on oral anticoagulants.
Sources
Related molecules
To explore in the « Anti-infectives » family and its neighbours.
See the whole « Anti-infectives » family · Back to the atlas
Supplements to consider
Beyond the plate, a single isolated nutrient can be worth discussing, to confirm with your doctor or pharmacist. Here is which one and in which form.
Probiotics
Probiotics are live micro-organisms, mainly lactobacilli and bifidobacteria. The CFU count and the number of strains are among the selection criteria; gastro-resistant capsules protect the bacteria from stomach acidity.
Preferred form gastro-resistant capsules, several strains, CFU count stated
Frequently asked questions
What is azithromycin used for?
Azithromycin is an antibiotic in the macrolide family, prescribed for certain bacterial infections (respiratory tract, ear, nose and throat, skin, sexually transmitted infections). It works by blocking bacteria from making proteins. The exact indication and duration are stated on your prescription: refer to the package leaflet and to your doctor or pharmacist.
What are the most common side effects of azithromycin?
Among the common side effects, the package leaflet lists digestive problems: diarrhea, nausea, abdominal pain and flatulence. Rarer effects also occur, notably heart rhythm disturbances in people at risk. For any bothersome or persistent symptom, consult the package leaflet and speak to your doctor or pharmacist.
Can you drink alcohol while taking azithromycin?
Alcohol is generally not advised during antibiotic treatment, as it can worsen digestive problems and fatigue. For your specific situation, rely on the package leaflet and on the advice of your doctor or pharmacist.
Does azithromycin interact with other medications?
Yes, azithromycin can interact with several medications, particularly those that prolong the QT interval (heart rhythm) and certain treatments such as anticoagulants. Always report all of your medications, including over-the-counter ones, and check for interactions in the package leaflet with your doctor or pharmacist.
How can you support your gut flora during antibiotic treatment?
A broad-spectrum antibiotic does not distinguish harmful bacteria from the useful bacteria in the gut, and research links this disruption of the flora to what is called antibiotic-associated diarrhea. Studies associate taking probiotics with better digestive tolerance during and after treatment. A diet rich in fiber and fermented foods (yogurt, kefir) complements this approach.
Which form of probiotics to consider with antibiotics?
The available research focuses mainly on documented strains such as Lactobacillus rhamnosus, in the form of capsules or sachets providing live cultures. It is often advised to take them spaced apart from the antibiotic dose and to continue for a few days after the end of treatment. Ask your pharmacist for advice on the strain and timing best suited to you.
Ces réponses portent sur le volet nutritionnel. Pour toute question sur votre médicament, la notice et votre médecin ou pharmacien font foi.