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Darvocet A500 (Oral)
Generic Name: propoxyphene and acetaminophen (Oral route)
a-seet-a-MIN-oh-fen, proe-POX-i-feen NAP-si-late
Accidental and intentional overdose with propoxyphene products either alone or in combination with other CNS depressants, including alcohol, has occurred, and may be fatal within the first hour. Many of the fatalities have occurred in patients with previous histories of emotional disturbances or suicidal ideation/attempts and/or concomitant administration of sedatives, tranquilizers, muscle relaxants, antidepressants, or other CNS-depressant drugs. Do not prescribe propoxyphene for patients who are suicidal or have a history of suicidal ideation. The metabolism of propoxyphene may be altered by strong CYP3A4 inhibitors leading to enhanced propoxyphene plasma levels; monitor patients closely and adjust dosages if necessary in patients receiving any CYP3A4 inhibitor concomitantly .
Medically reviewed: March 25, 2018
Commonly used brand name(s)
In the U.S.
- Balacet 325
- Darvocet A500
- Darvocet-N 100
- Darvocet-N 50
- Propoxacet-N 100
Available Dosage Forms:
Therapeutic Class: Opioid/Acetaminophen Combination
Chemical Class: Propoxyphene
Uses For Darvocet A500
Propoxyphene and acetaminophen combination is used to relieve mild to moderate pain. Propoxyphene belongs to the group of medicines called narcotic analgesics (pain medicines). It acts on the central nervous system (CNS) to relieve pain.
Acetaminophen is used to relieve pain and reduce fever in patients. It does not become habit-forming when taken for a long time. But acetaminophen may cause other unwanted effects when taken in large doses, including liver damage.
When propoxyphene is used for a long time, it may become habit-forming, causing mental or physical dependence. However, people who have continuing pain should not let the fear of dependence keep them from using narcotics to relieve their pain. Mental dependence (addiction) is not likely to occur when narcotics are used for this purpose. Physical dependence may lead to withdrawal side effects if treatment is stopped suddenly. However, severe withdrawal side effects can usually be prevented by gradually reducing the dose over a period of time before treatment is stopped completely.
Products containing propoxyphene were withdrawn from the U.S. market starting November 19, 2010.
This medicine was available only with your doctor's prescription.
Before Using Darvocet A500
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of propoxyphene and acetaminophen combination in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of propoxyphene and acetaminophen combination in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving propoxyphene and acetaminophen combination.
|All Trimesters||C||Animal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.|
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with Medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Chloral Hydrate
- Morphine Sulfate Liposome
- Sodium Oxybate
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with Food/Tobacco/Alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.
Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Alcohol abuse, or history of or
- Brain tumor, history of or
- Chronic obstructive pulmonary disease (COPD) or
- Cor pulmonale (serious heart condition) or
- Drug dependence, especially with narcotics, or history of or
- Gallbladder disease or gallstones or
- Head injuries, history of or
- Hypovolemia (low blood volume)—Use with caution. May increase risk for more serious side effects.
- Asthma, severe or
- Breathing problems, severe (e.g., hypoxia) or
- Paralytic ileus (intestine stops working and may be blocked) or
- Respiratory depression (very slow breathing) or
- Suicidal ideation (thoughts of hurting or killing oneself), history of—Should not be used in patients with these conditions.
- Hypotension (low blood pressure) or
- Pancreatitis (inflammation of the pancreas)—Use with caution. May make these conditions worse.
- Kidney disease or
- Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper Use of propoxyphene and acetaminophen
This section provides information on the proper use of a number of products that contain propoxyphene and acetaminophen. It may not be specific to Darvocet A500. Please read with care.
Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. This is especially important for elderly patients, who may be more sensitive to the effects of pain medicines. If too much of this medicine is taken for a long time, it may become habit-forming (causing mental or physical dependence). Liver damage can occur if large amounts of acetaminophen are taken for a long time.
This combination medicine contains acetaminophen (Tylenol®). Carefully check the labels of all other medicines you are using, because they may also contain acetaminophen. It is not safe to use more than 4 grams (4,000 milligrams) of acetaminophen in one day (24 hours).
This medicine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For mild to moderate pain:
- Adults—One or two tablets every 4 hours as needed. Your doctor may adjust your dose if needed. However, the dose is usually not more than 6 to 12 tablets per day.
- Children—Use and dose must be determined by your doctor.
- For mild to moderate pain:
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Throw any unused medicine by mixing it with used coffee grounds or kitty litter and place it in a sealable bag, empty can, or container.
Precautions While Using Darvocet A500
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 this medicine 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.
Darvocet A500 Side Effects
Along with its needed effects, a medicine 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:Rare
- Abdominal or stomach pain
- clay-colored stools
- dark urine
- loss of appetite
- unpleasant breath odor
- unusual tiredness or weakness
- vomiting of blood
- yellow eyes or skin
- bloody or black, tarry stools
- bloody or cloudy urine
- change in consciousness
- chest pain or discomfort
- decreased urine output
- difficult or troubled breathing
- dilated neck veins
- extreme fatigue
- fast, slow, pounding, or irregular heartbeat or pulse
- fever with or without chills
- general feeling of discomfort or illness
- irregular, fast, slow, or shallow breathing
- joint pain, stiffness, or swelling
- light-colored stools
- loss of consciousness
- low blood pressure or pulse
- muscle aches and pains
- muscle tremors
- 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
- right upper stomach pain and fullness
- runny nose
- severe stomach pain
- shakiness and unsteady walk
- shortness of breath
- sore throat
- stomach cramps
- 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
- trouble sleeping
- troubled breathing or swallowing
- unsteadiness, trembling, or other problems with muscle control or coordination
- very slow breathing
- very slow heartbeat
- vomiting of blood or material that looks like coffee grounds
- weight gain
Get emergency help immediately if any of the following symptoms of overdose occur:Symptoms of overdose
- bluish color of the fingernails, lips, skin, palms, or nail beds
- coughing that sometimes produces a pink frothy sputum
- decreased awareness or responsiveness
- difficult, fast, or noisy breathing, sometimes with wheezing
- dilated pupils
- increased sweating
- 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
Some side effects 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:More common
- Relaxed and calm feeling
- Abnormal behavior
- blurred or loss of vision
- disturbed color perception
- double vision
- false or unusual sense of well-being
- halos around lights
- 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
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
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More about Darvocet A500 (acetaminophen / propoxyphene)
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Images
- Drug Interactions
- Support Group
- 5 Reviews – Add your own review/rating
- Drug class: narcotic analgesic combinations
Other brands: Darvocet-N 50