Acetaminophen / Propoxyphene Side Effects

Applies to acetaminophen/propoxyphene: oral tablet.

Precautions

It is very important that your doctor check your progress while you are taking this medicine. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.

Talk to your doctor first before you Stop taking acetaminophen / propoxyphene and changing to another pain medicine.

This medicine can cause changes in heart rhythms, such as conditions called PR, QRS, and QT prolongation. It may change the way your heart beats and cause fainting, dizziness, lightheadedness, or serious side effects in some patients. Contact your doctor right away if you have any symptoms of heart rhythm problems, such as fast, pounding, or irregular heartbeats.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that can make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for allergies or colds; sedatives, tranquilizers, or sleeping medicine; other prescription pain medicine or narcotics; medicine for seizures or barbiturates; muscle relaxants; or anesthetics, including some dental anesthetics. Also, there may be a greater risk of liver damage if you drink three or more alcoholic beverages while you are taking acetaminophen. Do not drink alcoholic beverages, and check with your doctor before taking any of the medicines listed above while you are using this medicine.

This medicine may be habit-forming. If you feel that the medicine is not working as well, do not use more than your prescribed dose. Call your doctor for instructions.

Dizziness, lightheadedness, or fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem. Also, lying down for a while may relieve the dizziness or lightheadedness.

This medicine may make you dizzy, drowsy, or lightheaded. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.

Using narcotics for a long time can cause severe constipation. To prevent this, your doctor may direct you to take laxatives, drink a lot of fluids, or increase the amount of fiber in your diet. Be sure to follow the directions carefully, because continuing constipation can lead to more serious problems.

If you have been using this medicine regularly for several weeks or longer, do not change your dose or suddenly stop using it without checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help prevent worsening of your condition and reduce the possibility of withdrawal symptoms, such as abdominal or stomach cramps, anxiety, fever, nausea, runny nose, sweating, tremors, or trouble with sleeping.

Using this medicine while you are pregnant may cause serious unwanted effects in your newborn baby. Tell your doctor right away if you think you are pregnant or if you plan to become pregnant while using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Other side effects

Some side effects of acetaminophen / propoxyphene 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:

Serious side effects

Along with its needed effects, acetaminophen / propoxyphene 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 acetaminophen / propoxyphene:

Get emergency help immediately if any of the following symptoms of overdose occur while taking acetaminophen / propoxyphene:

Symptoms of overdose

• agitation
• bluish color of the fingernails, lips, skin, palms, or nail beds
• convulsion
• coughing that sometimes produces a pink frothy sputum
• decreased awareness or responsiveness
• depression
• difficult, fast, or noisy breathing, sometimes with wheezing
• dilated pupils
• hostility
• increased sweating
• irritability
• lethargy
• muscle tremors
• muscle twitching
• pale skin
• pounding or rapid pulse
• rapid weight gain
• rapid, deep breathing
• severe sleepiness
• sleepiness or unusual drowsiness
• slow to respond
• slurred speech
• weight loss

For healthcare professionals

Applies to acetaminophen / propoxyphene: oral tablet.

General adverse events

General side effects including drug tolerance and influenza type illness have been reported with the use of propoxyphene.

Other

Other side effects including propoxyphene dependence have been reported (although the abuse liability of propoxyphene is less than that of some other narcotic analgesics). Withdrawal symptoms (after either abrupt cessation or fast tapering) have been reported to 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 with propoxyphene.

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

Gastrointestinal

Gastrointestinal side effects of acetaminophen are rare, except in alcoholics and after overdose. Cases of acute pancreatitis have been reported rarely with acetaminophen use. Nausea, vomiting, and constipation are relatively common effects of propoxyphene. Gastrointestinal bleeding and acute pancreatitis have also been reported with the use of propoxyphene.^[Ref]

One study has suggested that acetaminophen may precipitate acute biliary pain and cholestasis. The mechanism of this effect may be related to inhibition of prostaglandin and alterations in the regulation of the sphincter of Oddi.

Elevated liver function tests, jaundice and hepatotoxicity have been reported in association with propoxyphene.

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

Cardiovascular

Cardiovascular side effects of propoxyphene 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 overdose.^[Ref]

Some of the cardiotoxic effects reported in association with propoxyphene may be attributable to its major active metabolite, norpropoxyphene.^[Ref]

Renal

Renal side effects of acetaminophen have been rare and have included acute tubular necrosis and interstitial nephritis. Cases of severe hypoglycemia have been reported in patients with chronic renal failure who received propoxyphene.^[Ref]

Acute tubular necrosis associated with acetaminophen usually occurs in conjunction with liver failure, but has been observed as an isolated finding in rare cases. Adverse acetaminophen renal effects are most often observed after overdose, after chronic abuse (often with multiple analgesics), or in association with acetaminophen-related hepatotoxicity. A possible increase in the risk of renal cell carcinoma has been associated with chronic acetaminophen use as well.

A single case of nephrogenic diabetes insipidus has been reported following overdose of propoxyphene (however, other causes of diabetes insipidus in that patient were not rigorously excluded).

The adverse effects of propoxyphene may be more likely and more severe in patients with renal insufficiency.^[Ref]

Hypersensitivity

Hypersensitivity side effects to acetaminophen have been reported rarely.

Hypersensitivity side effects to propoxyphene have also been reported.^[Ref]

Genitourinary

Genitourinary side effects have included a case of retroperitoneal fibrosis in association with propoxyphene therapy.^[Ref]

Hematologic

Hematologic side effects including rare cases of thrombocytopenia associated with acetaminophen have been reported. Acute thrombocytopenia has also been reported as having been caused by sensitivity to acetaminophen glucuronide, the major metabolite of acetaminophen. Methemoglobinemia with resulting cyanosis has also been observed in the setting of acute overdose. Cases of hemolytic anemia, pancytopenia, and disseminated intravascular coagulation after administration (or abuse) of propoxyphene-containing compounds have been reported rarely.^[Ref]

Dermatologic

Dermatologic side effects including rashes have been reported in association with both propoxyphene and acetaminophen. Itch has also been reported with the use of propoxyphene.^[Ref]

General erythematous skin rashes associated with acetaminophen have been reported, but are rare. A rare case of bullous erythema associated with acetaminophen has been reported.^[Ref]

Respiratory

Respiratory side effects including a case of acetaminophen-induced eosinophilic pneumonia have been reported.

Respiratory side effects including dyspnea have been reported with the use of propoxyphene.^[Ref]

Musculoskeletal

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 administer the drug via intramuscular injection.^[Ref]

Hepatic

Hepatic side effects of acetaminophen including severe and sometimes fatal dose dependent hepatitis have been reported in alcoholic patients. Hepatotoxicity has been increased during fasting. Several cases of hepatotoxicity from chronic acetaminophen therapy at therapeutic doses have also been reported despite a lack of risk factors for toxicity.

Hepatic side effects of propoxyphene have included elevated liver function tests, jaundice, hepatic steatosis, hepatomegaly, hepatocellular injury, and hepatotoxicity.^[Ref]

Alcoholic patients may develop hepatotoxicity after even modest doses of acetaminophen. In healthy patients, approximately 15 grams of acetaminophen is necessary to deplete liver glutathione stores by 70% in a 70 kg person. However, hepatotoxicity has been reported following smaller doses. Glutathione concentrations may be repleted by the antidote N-acetylcysteine. One case report has suggested that hypothermia may also be beneficial in decreasing liver damage during overdose.

In a recent retrospective study of 306 patients admitted for acetaminophen overdose, 6.9% had severe liver injury but all recovered. None of the 306 patients died.

A 19-year-old female developed hepatotoxicity, reactive plasmacytosis and agranulocytosis followed by a leukemoid reaction after acute acetaminophen toxicity.

The adverse effects of acetaminophen-propoxyphene may be more likely and more severe in patients with liver disease.^[Ref]

Metabolic

Metabolic side effects including metabolic acidosis have been reported following a massive overdose of acetaminophen.

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

In the case of metabolic acidosis, causality is uncertain as more than one drug was ingested. The case of metabolic acidosis followed the ingestion of 75 grams of acetaminophen, 1.95 grams of aspirin, and a small amount of a liquid household cleaner. The patient also had a history of seizures which the authors reported may have contributed to an increased lactate level indicative of metabolic acidosis.

Ocular

Ocular side effects including eye swelling and vision blurred have been reported with the use of propoxyphene.

Nervous system

Nervous system side effects of propoxyphene have included dizziness, sedation, stupor, delirium, somnolence, ataxia, coma, syncope, and respiratory depression. The sedative effects of propoxyphene have been associated with a 60% increased risk of hip fracture in elderly patients.^[Ref]

Psychiatric

Psychiatric side effects including abnormal behavior, confusional state, hallucinations, and mental status change have been reported with the use of propoxyphene.

See also:

Further information

Acetaminophen/propoxyphene side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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