These products are a combination of triamterene (DYRENIUM) and hydrochlorothiazide (ESIDRIX, HYDRODIURIL, MICROZIDE) and are used to treat high blood pressure (hypertension). Older adults should never use drugs that contain a fixed combination of triamterene and hydrochlorothiazide as a first-choice drug.
Public Citizen lists these drugs for Limited Use.
Triamterene can cause kidney stones, kidney failure and retention of too much potassium (especially if potassium supplements are also given), adverse effects that may be fatal., Because of these effects, we do not recommend that any older adult use triamterene alone.
In addition to triamterene’s dangers, there are good reasons not to use any fixed-combination drug for high blood pressure. A single drug is often enough to control high blood pressure. There is no reason to put yourself at extra risk by taking drugs you do not need.
First-line treatment for high blood pressure
If you have high blood pressure, the best way to reduce or eliminate your need for medication is by improving your diet, losing weight, exercising, and decreasing your salt and alcohol intake. Mild hypertension can be controlled by proper nutrition and exercise. If these measures do not lower your blood pressure enough and you need medication, hydrochlorothiazide, a water pill, is the drug of choice, starting with a low dose of 12.5 milligrams (mg) daily. It also costs less than other blood-pressure drugs.
There is growing evidence that thiazide diuretics, such as hydrochlorothiazide, significantly decrease the rate of bone mineral loss in both men and women because they reduce the amount of calcium lost in the urine. Research now suggests that thiazide diuretics may protect against hip fracture.
Since DYAZIDE and MAXZIDE contain 25 mg and 50 mg of hydrochlorothiazide respectively, it is not possible for older adults to start with a lower starting dose of 12.5 mg if either of these products is used. People responding to 12.5 mg of hydrochlorothiazide alone will have a lower risk of adverse effects and less need to use potassium supplements or a potassium-saving drug such as triamterene.
If your high blood pressure is more severe, and hydrochlorothiazide alone does not control it, another high-blood-pressure-controlling drug may be used instead. In this case, your doctor would prescribe the hydrochlorothiazide and the second drug separately, with the dose of each drug adjusted to meet your needs, rather than using a product that combines the drugs in advance in a fixed combination.
If you are taking this fixed-combination drug, ask your doctor about changing your prescription.
Whatever drugs you take for high blood pressure, once your blood pressure has been normal for a year or more, a cautious decrease in dose and renewed attention to nondrug treatment may be worth trying, according to The Medical Letter on Drugs and Therapeutics.
An editorial in the British Medical Journal (BMJ) stated:
Treatment of hypertension is part of preventive medicine and like all preventive strategies, its progress should be regularly reviewed by whoever initiates it. Many problems could be avoided by not starting antihypertensive treatment until after prolonged observation. ... Patients should no longer be told that treatment is necessarily for life: the possibility of reducing or stopping treatment should be mentioned at the outset.
The May 2012 issue of Worst Pills, Best Pills News highlighted a recent BMJ study indicating that patients taking several types of commonly used antihypertensive medications are at increased risk of developing gout, a type of arthritis.
The BMJ study also showed that a small number of other antihypertensive drugs appear to have the opposite effect, decreasing the risk of gout.
All patients should be informed of the risk of gout with diuretics, beta-blockers, angiotensin-converting enzyme inhibitors (ACE inhibitors) and non-lorsartan angiotensin II receptor blockers (ARBs) when starting these medications or whenever the dose of the medications is increased .
The April 2013 issue of Worst Pills, Best Pills News discusses another recent BMJ study. This study suggests that an increased risk of acute kidney injury (AKI) is associated with combining nonsteroidal anti-inflammatory drugs (NSAIDs) with two antihypertensive drugs: a diuretic plus either an ACE inhibitor or an ARB. The risk was found to be highest during the first 30 days of starting an NSAID in patients who also are already taking a diuretic plus an ACE inhibitor or an ARB.
The study found that patients currently using a triple-therapy combination — a diuretic, an ACE inhibitor or an ARB, and an NSAID — have a 31 percent greater risk of developing AKI compared with current users of a diuretic plus an ACE inhibitor or an ARB without an NSAID.
Regulatory actions surrounding hydrochlorothiazide
2011: In March, the Food and Drug Administration (FDA) issued the following warning concerning the use of hydrochlorothiazide products:
Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma. Symptoms include acute onset of decreased visual acuity or ocular pain and typically occur within hours to weeks of drug initiation. Untreated acute angle-closure glaucoma can lead to permanent vision loss. The primary treatment is to discontinue hydrochlorothiazide as rapidly as possible. Prompt medical or surgical treatments may need to be considered if the intraocular pressure remains uncontrolled. Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy.