Skip to main content

Diphenhydramine / naproxen Side Effects

Medically reviewed by Last updated on Jun 13, 2022.

Applies to diphenhydramine/naproxen: oral tablet.

Serious side effects

Along with its needed effects, diphenhydramine / naproxen 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 immediately if any of the following side effects occur while taking diphenhydramine / naproxen:

Incidence not known

  • Bloody or black, tarry stools
  • chest pain, discomfort, or tightness
  • confusion
  • constipation
  • decreased urine output
  • diarrhea
  • difficulty in speaking
  • dilated neck veins
  • double vision
  • headache
  • heartburn
  • inability to move the arms, legs, or facial muscles
  • inability to speak
  • indigestion
  • irregular breathing
  • irregular heartbeat
  • nausea
  • pain or discomfort in the arms, jaw, back, or neck
  • severe stomach pain
  • slow speech
  • stomach cramping or burning
  • sweating
  • swelling of the face, fingers, feet, or lower legs
  • trouble breathing
  • vomiting
  • vomiting of blood or material that looks like coffee grounds
  • weight gain

Other side effects

Some side effects of diphenhydramine / naproxen 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:

Incidence not known

  • Difficulty swallowing

For Healthcare Professionals

Applies to diphenhydramine / naproxen: oral tablet.


The manufacturer has not provided adverse event information.[Ref]


1. "Product Information. Benadryl (diphenhydramine)." Parke-Davis (2002):

2. "Product Information. Naprosyn (naproxen)." Syntex Laboratories Inc (2002):

3. "Product Information. Diphenhydramine Hydrochloride-Naproxen Sodium (diphenhydramine-naproxen)." Amneal Pharmaceuticals LLC (2020):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.