Consumer Information

Primsol

Generic name: Trimethoprim
Brand names: Primsol

Why is Primsol prescribed?

Primsol is a liquid antibiotic prescribed to treat acute ear infections in children over six months old, and uncomplicated urinary tract infections in adults. Your doctor will order tests to make sure Primsol is effective against the bacteria that caused your infection. Primsol is not recommended in cases of chronic infection due to the risks associated with long-term use.

Most important fact about Primsol

Primsol can cause a serious blood cell disorder, especially if taken in high doses or for a long period of time. This condition requires prompt medical treatment. Notify your doctor immediately if you develop fever, pale skin, sore throat, or small red or purple spots on the skin. Your doctor may order blood tests to monitor your health while taking Primsol.

How should you take Primsol?

Primsol liquid is taken by mouth with or without food, twice daily, 12 hours apart. When Primsol is prescribed in just one daily dose, take it at about the same time each day. Take Primsol exactly as directed and do not take more than your doctor has prescribed.

If you miss a dose...
Take the forgotten dose as soon as you remember. However, if it is almost time for your next dose, skip the one you missed and return to your regular schedule. Do not take two doses at once.

Storage instructions...
Store at room temperature, protected from light.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe to continue using Primsol.

Side effects may include:
Diarrhea or rash

Why should Primsol not be prescribed?

Primsol should not be taken if you have an allergic reaction to it or to other drugs that contain the same ingredient, trimethoprim. Do not take Primsol if you have been diagnosed with megaloblastic (pernicious) anemia; a blood cell disorder caused by a B-vitamin deficiency.

Special warnings about Primsol

Primsol should not be used for the prevention or long-term treatment of ear infection or urinary tract infection.

Primsol should be used with caution if you have a blood or bone marrow disorder, liver or kidney disease, or you have ever had vitamin deficiencies. Primsol interferes with your body's ability to absorb folic acid (folate, vitamin B9), an important B-vitamin. Your doctor may have you take extra vitamins during treatment with Primsol.

Primsol should not be given to infants under 2 months of age.

Possible food and drug interactions when taking Primsol

When Primsol is used with certain other drugs, the effects of either drug could be increased, decreased, or altered. It is especially important to check with your doctor before combining Primsol with methotrexate or phenytoin.

Special information if you are pregnant or breastfeeding

Primsol can interfere with the absorption of important vitamins that are vital to your baby's development during pregnancy. It is not recommended for pregnant women unless your doctor determines the benefit to your health outweighs the risk to your unborn baby. Tell your doctor immediately if you are pregnant or plan to become pregnant while taking Primsol.

Primsol appears in human breast milk and can harm your nursing infant. Your doctor may advise you to stop breastfeeding if Primsol is essential to your health.

Recommended dosage for Primsol

ADULTS

The usual adult dose is 100 milligrams taken twice a day, or 200 milligrams taken once a day for 10 days.

For adults with impaired kidney function, the recommended dose of Primsol will be half the usual dose.

CHILDREN

For children aged 6 months and older, the recommended daily dose is 10 milligrams per 2.2 pounds of body weight every 12 hours for 10 days. Follow the directions that come with the prescription carefully and if you have questions, call your doctor or pharmacy.

For children with impaired kidney function, the recommended dose of Primsol will be half the usual dose.