Propoxyphene

What is propoxyphene?

Propoxyphene is an opioid medicine that is used to control pain. Propoxyphene is available combined with acetaminophen as 50-mg (Darvocet-N 50^®) and 100-mg (Darvocet-N 100^®) orange caplets. Both are taken by mouth.

Possible side effects of propoxyphene

Early

• Feeling drowsy
• Nausea
• Slower than normal rates of breathing
• Low blood pressure

Later (usually more than a day after treatment starts)

• Constipation
• Itching and hives
• Feeling drowsy; sedation
• Nausea and vomiting
• Feeling dizzy
• Mood changes (feeling sadder or happier than usual)
• Dry mouth
• Fainting
• Trouble urinating

These are the most common side effects, but there may be others. Please report all side effects to the doctor or nurse.

In case of a severe side effect or reaction, call the doctor, nurse, or pharmacist at 595-3300. If you are outside the Memphis area, dial toll-free 1-866-2STJUDE (1-866-278-5833), and press 0 once the call is connected.

Special instructions for propoxyphene

• If you have any of the side effects listed above, most should decrease after taking propxoyphene for a couple of days. Tell your doctor if the side effects increase while you are taking this medicine. You may need to take less propoxyphene.
• If you are taking this medicine regularly, do not stop taking it until your doctor tells you to do so. Stopping propoxyphene without slowly decreasing the dose can lead to diarrhea, headache, sweating, muscle cramps, trouble sleeping, nausea, vomiting, or feeling restless.
• This medicine may cause you to feel dizzy or drowsy. Propoxyphene may impair your ability to drive a car or operate heavy machinery. Do not take part in these activities if you are sleepy, drowsy, dizzy, or not alert after taking propoxyphene.
• If you have not slept because of your pain, when you start this medicine you may sleep more for the first few days to “catch up” on missed sleep.
• If you are taking this medicine regularly, you should increase your fluid and fiber intake to help prevent constipation. Tell your doctor or nurse if you have not had a bowel movement in 3 to 5 days. You may need to take a stool softener or laxative to relieve your constipation.
• If you have taken propoxyphene for a long time, your doctor may slowly wean you off propoxyphene. During this time, watch for a sudden onset of diarrhea, headache, sweating, muscle cramps, trouble sleeping, nausea, vomiting, or feeling restless. If these symptoms occur, call your doctor right away. It could mean your dose is being decreased too fast.
• While you are taking propoxyphene plus acetaminophen, do not take other medicines that also contain acetaminophen (Tylenol^®).
• Other medicines can increase the drowsy feeling caused by propoxyphene. These medicines include:
  • Alcohol (found in many over-the-counter cough/cold medicines)
  • Diphenhydramine (over-the-counter Benadryl^®)
  • Promethazine
  • Diazepam or lorazepam
  • Antidepressants (such as amitriptyline)
  • Medicines used to treat seizures, such as carbamazepine, phenytoin, gabapentin, phenobarbital, and valproic acid.
• Always tell your doctor if you are taking any of these medicines or if you start taking any new medicine while you are taking propoxyphene.