Do NOT use Triamterene if:

• you are allergic to any ingredient in Triamterene
• you are taking potassium supplements, another potassium-sparing diuretic (eg, amiloride), or an aldosterone blocker (eg, eplerenone)
• you are unable to urinate or have high blood potassium levels or severely decreased liver or kidney function.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Triamterene. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have heart problems, diabetes, kidney damage caused by diabetes, liver or kidney problems, low blood sodium levels, a high acidity of body fluids, dehydration, or a history of kidney stones.

Some medicines may interact with Triamterene. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Aldosterone blockers (eg, eplerenone), angiotensin-converting enzyme (ACE) inhibitors (eg, enalapril), angiotensin II receptor antagonists (eg, valsartan), cyclosporine, penicillin G potassium, otherpotassium-sparing diuretics (eg, amiloride), or potassium supplements because high blood potassium levels may occur and cause listlessness, confusion, abnormal skin sensations of the arms and legs, heaviness of the limbs, slow or irregular heartbeat, or stopping of the heart
• Insulin and oral hypoglycemics (eg, chlorpropamide) because the risk of side effects, such as severe low blood sodium and changes in blood sugar, may be increased
• Lithium because risk of side effects and toxicity may be increased by Triamterene
• Nonsteroidal anti-inflammatory drugs (NSAIDs) (eg, indomethacin) because the effectiveness of Triamterene may be decreased and the risk of kidney problems and high blood potassium levels may be increased.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Triamterene may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Triamterene may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use Triamterene with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Check with your doctor before you use a salt substitute or a product that has potassium in it.
• Tell your doctor or dentist that you take Triamterene before you receive any medical or dental care, emergency care, or surgery.
• Lab tests, including blood electrolytes, blood cell counts, kidney and liver function tests, blood uric acid levels, and blood pressure, may be performed while you use Triamterene. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Use Triamterene with caution in the elderly; they may be more sensitive to its effects.
• Triamterene should not be used in children; safety and effectiveness in children have not been confirmed.
• Pregnancy and breast-feeding: It is not known if Triamterene can cause harm to the fetus. If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Triamterene while you are pregnant. It is not known if Triamterene is found in breast milk. Do not breastfeed while taking Triamterene.

All medicines may cause side effects, but many people have no, or minor, side effects.

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

Stop using this medication and call your doctor at once if you have a serious side effect such as:

• numbness or tingly feeling;
• muscle pain or weakness;
• slow, fast, or uneven heartbeat;
• feeling drowsy, restless, or light-headed;
• urinating less than usual or not at all;
• shallow breathing;
• tremors, confusion; or
• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

• mild nausea or vomiting;
• dizziness, headache;
• gas, stomach pain; or
• skin rash.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.