Dynabac D5-Pak Side Effects

Generic Name: dirithromycin

Note: This page contains information about the side effects of dirithromycin. Some of the dosage forms included on this document may not apply to the brand name Dynabac D5-Pak.

Not all side effects for Dynabac D5-Pak may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to dirithromycin: oral tablet enteric coated

Along with its needed effects, dirithromycin (the active ingredient contained in Dynabac D5-Pak) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur while taking dirithromycin:

  • Abdominal tenderness
  • fever
  • severe abdominal or stomach cramps and pain
  • watery and severe diarrhea, which may also be bloody

Some side effects of dirithromycin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common
  • Diarrhea
  • dizziness
  • headache
  • nausea
  • vomiting
  • weakness

For Healthcare Professionals

Applies to dirithromycin: oral delayed release tablet


Although not observed among patients taking dirithromycin (the active ingredient contained in Dynabac D5-Pak) rare cases of cholestatic hepatitis have been associated with the use of macrolide antibiotics in general.

Gastrointestinal side effects are common. In clinical trials consisting of more than 3000 patients treated with daily doses of 500 mg for approximately 7 to 14 days, 2.6% discontinued therapy because of adverse reactions, of which 40% were due to nausea or abdominal pain. Overall, abdominal pain has been reported in 10%, nausea or diarrhea in 8%, vomiting or dyspepsia in 3%, and flatulence in approximately 2% of patients. Anorexia, constipation, dry mouth, epistaxis, gastritis, gastroenteritis, and mouth ulceration have been reported in less than 1% of patients.

Pseudomembranous colitis has been reported with nearly all antibacterial agents, including dirithromycin, and may range in severity from mild to life-threatening.

Nervous system

Nervous system side effects have included headache (9%), dizziness/vertigo (2%), asthenia (2%), nonspecific pain (2%), and insomnia (1%). Amblyopia, anxiety, depression, malaise, paresthesias, somnolence, taste alterations, tinnitus, and tremors have been reported in less than 1% of patients. Although not observed among patients taking dirithromycin (the active ingredient contained in Dynabac D5-Pak) a few cases of transient deafness have been associated with the use of high doses of a related macrolide, erythromycin.


Hypersensitivity reactions are rare. Rash and pruritus/urticaria have been reported in 1.4% and 1.2% of patients, respectively. Although not observed among patients taking dirithromycin (the active ingredient contained in Dynabac D5-Pak) bullous fixed eruptions and serious allergic reactions including anaphylaxis have been rarely associated with the use of macrolide antibiotics.


QT prolongation associated with the use of some macrolide antibiotics has been reported both in otherwise healthy patients and in patients with a history of heart disease or who were on other potentially arrhythmogenic drugs. Most affected patients were receiving erythromycin intravenously.

Cardiovascular side effects have not been observed among patients taking dirithromycin. Other macrolide antibiotics including azithromycin, clarithromycin and erythromycin, have rarely been associated with QT segment prolongation. Ventricular arrhythmias such as torsade de pointes have been reported with these agents.


Respiratory system side effects have rarely included dyspnea and/or cough.

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