Darvon-N Side Effects

Generic Name: propoxyphene

Note: This page contains information about the side effects of propoxyphene. Some of the dosage forms included on this document may not apply to the brand name Darvon-N.

Not all side effects for Darvon-N 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 propoxyphene: oral capsule, oral suspension, oral tablet

In addition to its needed effects, some unwanted effects may be caused by propoxyphene (the active ingredient contained in Darvon-N). In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking propoxyphene:

  • Abdominal or stomach pain
  • chills
  • clay-colored stools
  • dark urine
  • dizziness
  • fever
  • headache
  • itching
  • loss of appetite
  • nausea
  • rash
  • unpleasant breath odor
  • unusual tiredness or weakness
  • vomiting of blood
  • yellow eyes or skin
Incidence not known
  • Bloating
  • bloody or black, tarry stools
  • bloody or cloudy urine
  • change in consciousness
  • chest pain or discomfort
  • confusion
  • constipation
  • darkened urine
  • decreased urine output
  • difficult or troubled breathing
  • dilated neck veins
  • drowsiness
  • extreme fatigue
  • fainting
  • fast, slow, pounding, or irregular heartbeat or pulse
  • fever with or without chills
  • hives
  • hoarseness
  • indigestion
  • irregular, fast or slow, or shallow breathing
  • irritation
  • itching
  • joint pain, stiffness, or swelling
  • light-colored stools
  • loss of consciousness
  • muscle tremors
  • no blood pressure or pulse
  • no breathing
  • pain or discomfort in the arms, jaw, back, or neck
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • pale or blue lips, fingernails, or skin
  • rapid, deep breathing
  • redness of the skin
  • restlessness
  • right upper abdominal or stomach pain and fullness
  • severe stomach pain
  • shakiness and unsteady walk
  • shortness of breath
  • stomach cramps
  • stopping of the heart
  • sudden decrease in the amount of urine
  • swelling of the eyelids, face, fingers, lips, hands, lower legs, or feet
  • thoughts of suicide
  • tightness in the chest
  • troubled breathing or swallowing
  • unconsciousness
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • vomiting of blood or material that looks like coffee grounds
  • weight gain
  • wheezing

If any of the following symptoms of overdose occur while taking propoxyphene, get emergency help immediately:

Symptoms of overdose
  • Bluish color of the fingernails, lips, skin, palms, or nail beds
  • convulsion
  • coughing that sometimes produces a pink frothy sputum
  • decreased awareness or responsiveness
  • difficult, fast, or noisy breathing, sometimes with wheezing
  • dilated pupils
  • muscle tremors
  • pale skin
  • pounding or rapid pulse
  • rapid, deep breathing
  • severe sleepiness
  • sleepiness or unusual drowsiness
  • slow to respond
  • slurred speech
  • weight loss

Some of the side effects that can occur with propoxyphene may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Relaxed and calm
Incidence not known
  • Abnormal behavior
  • blurred or loss of vision
  • diarrhea
  • disturbed color perception
  • double vision
  • false or unusual sense of well-being
  • halos around lights
  • mental depression or anxiety
  • muscular pain, tenderness, wasting, or weakness
  • night blindness
  • nightmares or unusually vivid dreams
  • overbright appearance of lights
  • seeing, hearing, or feeling things that are not there
  • swelling of the eye
  • tunnel vision

For Healthcare Professionals

Applies to propoxyphene: oral capsule, oral tablet


In general, the adverse effects of propoxyphene (the active ingredient contained in Darvon-N) may be more likely and more severe in patients with renal and/or liver disease.

General side effects including drug tolerance and influenza type illness have been reported.

Nervous system

Nervous system side effects have included dizziness, sedation, stupor, delirium, somnolence, ataxia, coma, syncope, and respiratory depression. The sedative effects of propoxyphene (the active ingredient contained in Darvon-N) have been associated with a 60% increased risk of hip fracture in elderly patients.


Other side effects have included dependence (although the abuse liability of propoxyphene (the active ingredient contained in Darvon-N) is less than that of some other narcotic analgesics). Withdrawal symptoms after either abrupt cessation or fast tapering may occur and include agitation, restlessness, anxiety, insomnia, tremor, tachycardia, hallucinations, psychosis, abdominal cramps, vomiting, sweating, and seizures.

Drug toxicity, multiple drug overdose, and narcotic overdose have also been reported.

Sensorineural deafness has been reported following chronic abuse and/or large doses of propoxyphene-containing compounds. Optic atrophy has been reported following overdose.


Some of the cardiotoxic effects reported in association with propoxyphene (the active ingredient contained in Darvon-N) may be attributable to its major active metabolite, norpropoxyphene.

Cardiovascular side effects have included arrhythmia, bradycardia, cardiac/respiratory arrest, congestive arrest, congestive heart failure (CHF), tachycardia, myocardial infarction (MI), hypotension, decreased blood pressure, elevated heart rate, abnormal heart rate, and dizziness. A variety of arrhythmias (including heart block) have been reported most often in association with propoxyphene overdose.


Gastrointestinal side effects have included nausea, vomiting, and constipation which have been relatively common. Gastrointestinal bleeding and acute pancreatitis have also been reported.

A case of ischemic colitis has been reported following an overdose of propoxyphene which was complicated by severe hypotension.


Genitourinary side effects including a case of retroperitoneal fibrosis have been reported.


Dermatologic side effects including rashes and itch have been reported.


Renal side effects have included a single case of nephrogenic diabetes insipidus following an overdose of propoxyphene (the active ingredient contained in Darvon-N) (however, other causes of diabetes insipidus in that patient were not rigorously excluded).


Hepatic side effects have included elevated liver function tests, jaundice, hepatic steatosis, hepatomegaly, hepatocellular injury, and hepatotoxicity.


Hematologic side effects have rarely included cases of hemolytic anemia, pancytopenia, and disseminated intravascular coagulation after administration (or abuse) of propoxyphene-containing compounds.


Local side effects have included inadvertent intra-arterial injection with ensuing vascular compromise and distal necrosis has been reported in propoxyphene-abusing patients.


Musculoskeletal side effects including myopathy and rhabdomyolysis have been reported after chronic oral use. Fibrous myopathy has also been reported in propoxyphene-abusing patients who administered the drug via intramuscular injection.


Metabolic side effects including metabolic acidosis have been reported. Cases of severe hypoglycemia have been reported in patients with chronic renal failure.


Ocular side effects including eye swelling and vision blurred have been reported.


Hypersensitivity side effects have been reported.


Psychiatric side effects including abnormal behavior, confusional state, hallucinations, and mental status change have been reported.


Respiratory side effects including dyspnea have been reported.

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