Norgesic Side Effects: What to Expect and When to Call Your Doctor

Norgesic combines three active ingredients — orphenadrine citrate (muscle relaxant), aspirin (NSAID), and caffeine (analgesic enhancer) — each of which can contribute to side effects. Most patients who take Norgesic as directed experience only mild, manageable side effects. However, some serious reactions are possible. This article breaks down what to expect and when a symptom warrants a call to your doctor.

Note: This is for informational purposes only. Contact your healthcare provider with questions about your specific situation.

Common Side Effects of Norgesic

The most frequently reported side effects of Norgesic are related to orphenadrine's mild anticholinergic properties and aspirin's GI effects. These are generally mild and often improve as your body adjusts to the medication:

Dizziness and lightheadedness: Common, especially in the first few doses. Avoid driving or operating heavy machinery until you know how Norgesic affects you.

Drowsiness: Orphenadrine has sedating properties. The caffeine in Norgesic partially offsets this, but drowsiness may still occur.

Dry mouth: An anticholinergic effect of orphenadrine. Staying hydrated and using sugar-free gum can help.

Blurred vision / dilated pupils: Anticholinergic effect; avoid driving if this occurs.

Nausea and stomach upset: Take Norgesic with food or a full glass of water to reduce GI irritation from the aspirin component.

Constipation: Common with anticholinergic medications. Maintain adequate fluid and fiber intake.

Tachycardia (fast heartbeat) and palpitations: Anticholinergic effect of orphenadrine. Usually mild and transient.

Urinary hesitancy or retention: More likely in men with enlarged prostate. If urination becomes difficult, contact your doctor.

Headache: The aspirin component can occasionally cause headache, particularly in patients sensitive to salicylates.

Ringing in the ears (tinnitus): Associated with aspirin, especially at higher doses. Persistent tinnitus should be reported to your doctor.

Serious Side Effects: When to Call Your Doctor Immediately

Stop taking Norgesic and call your doctor right away or go to the emergency room if you experience any of the following:

Signs of GI bleeding: Bloody, black, or tarry stools; blood in vomit; severe stomach pain. The aspirin in Norgesic can rarely cause serious GI hemorrhage.

Signs of a serious allergic reaction (anaphylaxis): Difficulty breathing, throat closing, swelling of lips/tongue/face, hives. Seek emergency care immediately.

DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms): Rash with fever, swollen lymph nodes, and internal organ involvement. Some DRESS cases have been fatal. Stop the medication immediately and seek urgent care.

Mental/mood changes: Confusion, hallucinations, agitation, or anxiety — particularly in elderly patients. These can be a sign of orphenadrine toxicity.

Seizures or loss of consciousness: Signs of overdose. Norgesic overdose symptoms include severe confusion, decreased breathing, seizures, and cold/clammy skin — call 911 immediately.

Special Warning: Do Not Use During Flu, Chickenpox, or Viral Illness

Norgesic contains aspirin. Do not give Norgesic to anyone — especially children or teenagers under 18 — who has chickenpox, influenza, or flu-like symptoms. Aspirin in the setting of viral illness increases the risk of Reye's Syndrome, a rare but serious and potentially fatal condition affecting the brain and liver. Adults with flu symptoms should also avoid Norgesic due to this risk.

Side Effects in Elderly Patients

Elderly patients may experience more pronounced anticholinergic effects — particularly confusion and urinary retention. The Norgesic prescribing information notes that "infrequently, an elderly patient may experience some degree of confusion." Caregivers and family members should monitor older adults taking Norgesic for signs of confusion or disorientation.

Tips to Minimize Side Effects

Take with food and a full glass of water to reduce GI irritation

Avoid alcohol — it increases both sedation (orphenadrine) and GI bleeding risk (aspirin)

Avoid driving until you know how the medication affects your alertness

Do not take additional aspirin-containing products while on Norgesic

Take only as prescribed — do not exceed the recommended dose to manage pain more effectively

For a full breakdown of drug interactions that can worsen side effects, see our article on Norgesic drug interactions.