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 as soon as possible if any of the following side effects occur:
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:
This medicine is a dye and will color your stools red. This color is not harmful and will disappear in a few days. Pyrvinium may also stain clothing red. If vomiting occurs, the vomit will be red in color.
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.
If your symptoms do not improve within a few days, or if they become worse, check with your doctor.
Pyrvinium may cause your skin to be more sensitive to sunlight than it is normally. Exposure to sunlight, even for brief periods of time, may cause a skin rash, itching, redness or other discoloration of the skin, or a severe sunburn. For a day or two after taking this medicine:
If you have a severe reaction from the sun, check with your doctor.
In some patients, pinworms may return after treatment with pyrvinium. Washing (not shaking) all bedding and nightclothes (pajamas) after treatment may help to prevent this. Some doctors may also recommend other measures to help keep your infection from returning. If you have any questions about this, check with your doctor.
No special preparations (for example, special diets, fasting, other medicines, laxatives, or enemas) are necessary before, during, or immediately after you take pyrvinium.
Use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.
Pinworms may be easily passed from one person to another, especially among persons in the same household. Therefore, all household members may have to be treated at the same time to prevent their infection or reinfection. Also, all household members may have to be treated again in 2 to 3 weeks to clear up the infection completely. Make sure each family member takes the correct amount, since the dose may be different for each person.
To help clear up your infection completely, take this medicine exactly as directed by your doctor. Read the instructions on the label and follow them carefully. The amount of medicine you need is based on your weight. You must take the exact amount if the medicine is going to work. A second course of pyrvinium is usually required to clear up the infection completely.
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.
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.
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.
Pyrvinium has been studied in children and, in effective doses, has not been reported to cause different side effects or problems in children than it does in adults. However, because of limited experience, caution is recommended in children weighing less than 10 kilograms (22 pounds). Older children are more likely to have stomach upset after receiving large doses.
Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of pyrvinium in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.
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.
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. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
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. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of pyrvinium. Make sure you tell your doctor if you have any other medical problems.
Pyrvinium is used to treat pinworms (enterobiasis). It will not work for other types of worm infections (for example, roundworms or tapeworms).
Pyrvinium is available only with your doctor’s prescription.