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Primsol

Generic Name: trimethoprim (trye METH oh prim)
Brand Name: Primsol

Medically reviewed on November 15, 2017

What is Primsol?

Primsol is an antibiotic that fights bacteria in the body.

Primsol is used to treat bladder or kidney infections, or ear infections caused by certain bacteria.

Primsol may also be used for purposes not listed in this medication guide.

Important Information

You should not use Primsol if you are allergic to it, or if you have a certain type of anemia caused by a folate (folic acid) deficiency.

Before using Primsol, tell your doctor if you have kidney disease, liver disease, or a folic acid deficiency.

Take Primsol for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Primsol will not treat a viral infection such as the common cold or flu.

Avoid exposure to sunlight or tanning beds. Primsol can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Before taking this medicine

You should not use Primsol if you are allergic to it, or if you have a certain type of anemia caused by a folate (folic acid) deficiency.

To make sure Primsol is safe for you, tell your doctor if you have any of these conditions:

  • a folate (folic acid) deficiency;

  • kidney disease;

  • liver disease; or

  • fever, sore throat, flu symptoms, pale skin, or purple or red pinpoint spots under your skin.

FDA pregnancy category C. It is not known whether Primsol will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Trimethoprim can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Primsol should not be given to a child younger than 6 months old.

How should I take Primsol?

Follow the directions on your prescription label. Do not take Primsol in larger or smaller amounts or for longer than recommended.

Take your medicine with a full glass of water.

Measure liquid medicine with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

Take this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Primsol will not treat a viral infection such as the common cold or flu.

This medication can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using Primsol.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Primsol overdose can occur if you accidentally take too much at one time. This can cause nausea, vomiting, dizziness, confusion, or depression.

Overdose can also occur slowly over a long period of time if your daily doses are too high. This can cause severe forms of some of the side effects listed in this medication guide.

What should I avoid while taking trimethoprim?

Avoid exposure to sunlight or tanning beds. Primsol can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Primsol side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • fever, chills, body aches, flu symptoms, sores in your mouth and throat;

  • pale skin, easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;

  • high potassium (slow heart rate, weak pulse, muscle weakness, tingly feeling); or

  • severe headache with muscle cramps, confusion, weakness, loss of coordination, feeling unsteady, and weak or shallow breathing.

Other common side effects may include:

  • stomach pain, vomiting, diarrhea;

  • sore or swollen tongue; or

  • mild itching or skin rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Primsol?

Tell your doctor about all medications you use, and those you start or stop using during your treatment with Primsol, especially:

This list is not complete. Other drugs may interact with trimethoprim, including prescription, over-the-counter, vitamin, and herbal products. Not all possible interactions are listed in this medication guide.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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