Azithromycin is a type of antibiotic called a macrolide antibiotic. It can be used to treat bacterial infections. A sufficient azithromycin dose depends on the condition being treated, the age of the patient and the route of administration.
A standard adult azithromycin dose includes five days of oral medications. The first day requires 500 milligrams taken orally. The dosage drops to 250 milligrams per day for the remaining four days. This dosage usually is enough to treat upper respiratory infection, bronchitis, pneumonia and tonsillitis.
Adult dosage for sinusitis requires 500 milligrams orally for three days. The treatment for cervicitis and chancroid require a one-time, 1-gram oral dosage. A seven-day treatment for typhoid fever involves 1,000 milligrams on the first day and 500 milligrams per day for the rest of the week.
Intravenous (IV) azithromycin dosage might be prescribed for adult patients. A 500-milligram IV for two days might be prescribed for severe mycoplasma pneumonia, to be followed by an oral dosage regimen of 250 milligrams for four days. Legionella pneumonia follows a similar dosage, with the oral medications continuing for as long as 10 days. Pelvic inflammatory disease follows its IV treatment with a week of oral pills.
Oral suspensions typically replace pills in prescriptions for children who are more than 6 months old. The medication typically is not prescribed for children who are younger than 6 months. A standard azithromycin dose for a child is 10 milligrams per 2.2 pounds (1 kg) once per day for three days. This dose might be prescribed for pneumonia and sinusitis.
An azithromycin dose in pill form might be prescribed to older children for certain conditions. Cystic fibrosis treatment might require 250 milligrams orally three times a week for children who are more than 6 years old. Older children, such as teenagers, might request that the doctor prescribes the pill form of the medication for conditions for which the oral suspension is normally prescribed.
Drug interactions may cause a doctor to alter an azithromycin dose. Some drugs that commonly interact with azithromycin include anticoagulant medications and immune system suppressant drugs. Side effects also can change the drug therapy. Common azithromycin side effects include stomach upset, diarrhea and mild rash. Serious side effects include difficulty breathing and swelling of the face or hands.
A patient should always keep his or her doctor updated on how the azithromycin treatment is working. Individual factors in a person's genetics can affect the effectiveness of a medication. This is called pharmacogenetics, and it can involve anatomical problems of which neither the patient nor doctor was previously aware.