The Z-Pack is a 5 day course of azithromycin and is used to treat a variety of bacterial infections including bronchitis, pneumonia, and sinusitis. The Z-Pack contains six, 250 mg tablets and is dosed as follows:

  • Two tablets (500 mg) on day one
  • One tablet once daily for four more days


While the 250 mg Z-Pack is the most common, it is also available as a Zithromax Tri-Pack. This product contains three 500 mg tablets that are to be dosed once daily.


The Z-Pack and Tri-Pack are typically well tolerated but like all medications, have side effects that some individuals may experience. Below, we break down the most common side effects by incidence rate.


Common Z-Pack Side Effects (>10% Incidence Rate)

  • Diarrhea
  • Nausea
  • Vomitting


Uncommon Z-Pack Side Effects (1-10% Incidence Rate)

  • Abdominal pain
  • Anorexia
  • Dizziness
  • Shortness of breath
  • Headache 
  • Itching
  • Agitation
  • Constipation
  • Heartburn


Rare Side Effects (<1% Incidence)

  • Arrhythmias (e.g. QT prolongation)
  • Ringing in the ears
  • Elevated hepatic enzymes
  • Tingling/numbness of extremities 
  • Low blood pressure
  • Anxiety
  • Sweating


As mentioned, the Z-Pack is generally well tolerated but is associated with certain side effects, like all medication. The most common ones are nausea and gastrointestinal effects but other side effects are possible as well (as shown above).