Triamterene and Hydrochlorothiazide

💊 What is Triamterene and Hydrochlorothiazide used for?

• •The label says this combination is used to treat high blood pressure (hypertension) or fluid buildup (edema) in people who develop low potassium (hypokalemia) when taking hydrochlorothiazide alone. It is also used for people who need a thiazide diuretic but whose potassium cannot safely drop, such as people taking digitalis medicines or people with a history of heart rhythm problems. The label says it is not usually the first medicine for edema or high blood pressure, except when low potassium cannot be risked. It may be used alone or with other blood pressure medicines, such as beta-blockers.

How it works

The label describes triamterene as a potassium-conserving diuretic, which helps the body hold on to potassium while removing extra fluid. It describes hydrochlorothiazide as a natriuretic agent, a thiazide that increases the removal of sodium and water through urine. The label does not describe the mechanism in more detail.

How it is usually taken

• •The label says the medicine is taken once a day as a single dose. The number of tablets depends on the strength and is set by the prescriber. The label warns that splitting the daily dose into divided doses has been linked to a higher risk of electrolyte imbalance and kidney problems. Blood potassium must be monitored during treatment, and the label says the dose should not be increased beyond the amounts it describes. Follow the instructions from your prescriber or pharmacist.

Comes as

• •37.5 mg triamterene / 25 mg hydrochlorothiazide tablets (green, oval, scored)
• •75 mg triamterene / 50 mg hydrochlorothiazide tablets (yellow, oval, scored)

⚠️ Triamterene and Hydrochlorothiazide side effects

🛑 Who should not take Triamterene and Hydrochlorothiazide, and who should be careful

The label says not to take it if

• 🚨The label says not to use it if your blood potassium is elevated (5.5 mEq/liter or higher).
• 🚨The label says not to use it if you have anuria, acute or chronic kidney insufficiency, or significant kidney impairment.
• 🚨The label says not to use it if you are allergic (hypersensitive) to triamterene, hydrochlorothiazide, or other sulfonamide-derived drugs.
• 🚨The label says not to use it with other potassium-conserving medicines, such as spironolactone or amiloride, or with other triamterene products.
• 🚨The label says not to use potassium supplements, potassium-containing salt substitutes, or potassium-enriched diets while taking it.
• 🚨Follow the instructions from your prescriber or pharmacist about whether this medicine is right for you.

Tell your doctor before taking it if

• •The label says potassium levels must be checked with blood tests at frequent intervals, especially when first starting, when doses change, or during any illness that may affect the kidneys.
• •The label says patients with mild kidney impairment should be monitored closely with frequent blood tests.
• •The label says the medicine should be avoided in people with diabetes. If it is used, blood electrolytes must be checked often.
• •Tell your prescriber if you have a history of sulfonamide or penicillin allergy, since the label lists these as risk factors for acute angle-closure glaucoma.
• •The label says to protect skin from the sun and to have regular skin cancer screening, because hydrochlorothiazide is linked to an increased risk of non-melanoma skin cancer.
• •Tell your prescriber about all medicines you take, especially ACE inhibitors, NSAIDs, lithium, and other blood pressure medicines.
• •Tell your prescriber if you are pregnant, planning pregnancy, or breastfeeding.

🔀 Triamterene and Hydrochlorothiazide with other medicines, food and alcohol

The label says to discuss these with your doctor or pharmacist

• •ACE inhibitors: the label says potassium-sparing agents should be used very cautiously, if at all, with ACE inhibitors because of a greatly increased risk of high potassium. Potassium should be checked often.
• •Potassium supplements, salt substitutes containing potassium, and other potassium-sparing medicines should not be used with it, according to the label.
• •NSAIDs such as indomethacin: the label reports acute kidney failure in a few patients taking these with triamterene and hydrochlorothiazide, and advises caution.
• •Lithium: the label says lithium generally should not be given with diuretics because of a high risk of lithium toxicity.
• •Other blood pressure medicines: thiazides may add to their effects, and dose adjustments may be needed.
• •Other medicines: thiazides may decrease the body's response to norepinephrine and increase response to tubocurarine.

Alcohol and food

The label does not give food instructions. It notes that orthostatic hypotension (a drop in blood pressure when standing) may be made worse by alcohol, barbiturates, or narcotics.

🤰 Triamterene and Hydrochlorothiazide in pregnancy and breastfeeding

Pregnancy

The label says the safe use of this combination in pregnancy has not been established. It says the drug should be used during pregnancy only if the potential benefit justifies the risk to the fetus. The label also says routine diuretic use in an otherwise healthy pregnant woman is inappropriate and that diuretics do not prevent toxemia of pregnancy.

Breastfeeding

The label says the combination has not been studied in nursing mothers. Triamterene appears in animal milk and may occur in human milk, and thiazides are excreted in human breast milk. The label says that if use is deemed essential, the patient should stop nursing.

🗓️ Storage, missed doses and taking too much

Storage

The label says to store at 20 to 25°C (68 to 77°F), with short excursions permitted between 15 and 30°C (59 to 86°F). It says to dispense in a child-resistant closure in a tight, light-resistant container.

If a dose is missed

The label does not say.

If too much is taken

The label says no specific data are available on overdose in humans and no specific antidote exists. Fluid and electrolyte imbalances are the most important concern. Excess triamterene may cause high potassium, dehydration, nausea, vomiting, weakness, and possibly low blood pressure. Excess hydrochlorothiazide has been linked to low potassium, low chloride, low sodium, dehydration, lethargy (which may progress to coma), and stomach irritation. Treatment is supportive. Seek emergency medical help right away if an overdose is suspected.

🗒️ Questions to ask about Triamterene and Hydrochlorothiazide

• Do I need blood tests to check my potassium, and how often?
• Are any of my other medicines, such as ACE inhibitors or potassium supplements, a concern with this medicine?
• Should I avoid salt substitutes that contain potassium?
• What signs of high potassium should I watch for?
• Am I at higher risk of skin cancer, and how should I protect my skin from the sun?
• What should I do if I notice sudden changes in my vision?

❓ Triamterene and Hydrochlorothiazide: frequently asked questions