This section needs additional citations for verification .(June 2012) |
Clinical data | |
---|---|
Trade names | Dyrenium, others |
AHFS/Drugs.com | Monograph |
MedlinePlus | a682337 |
Pregnancy category |
|
Routes of administration | By mouth |
ATC code | |
Legal status | |
Legal status | |
Pharmacokinetic data | |
Bioavailability | 30-70% |
Protein binding | 67% |
Metabolism | hydroxylation to para-hydroxytriamterene |
Elimination half-life | 1-2 hours, active metabolite 3 hours |
Excretion | renal <50%, 21% unchanged |
Identifiers | |
| |
CAS Number | |
PubChem CID | |
IUPHAR/BPS | |
DrugBank | |
ChemSpider | |
UNII | |
KEGG | |
ChEMBL | |
CompTox Dashboard (EPA) | |
ECHA InfoCard | 100.006.278 |
Chemical and physical data | |
Formula | C12H11N7 |
Molar mass | 253.269 g·mol−1 |
| |
(what is this?) (verify) |
Triamterene (traded under names such as Dyrenium and Dytac) is a potassium-sparing diuretic often used in combination with thiazide diuretics for the treatment of high blood pressure or swelling. The combination with hydrochlorothiazide, is known as hydrochlorothiazide/triamterene.
Common side effects may include a depletion of sodium, folic acid, and calcium, nausea, vomiting, diarrhea, headache, dizziness, fatigue, and dry mouth. Serious side effects may include heart palpitations, tingling/numbness, fever, chills, sore throat, rash, and back pain. Triamterene can also cause kidney stones through direct crystallization or by seeding calcium oxalate stones. Triamterene is best avoided in patients with chronic kidney disease due to the possibility of hyperkalemia. People using this drug should use salt substitute cautiously. [2]
Triamterene may impart a blue fluorescent color to the urine.
Diabetes: Use with caution in people with prediabetes or diabetes mellitus as there may be a change in glucose control.
Liver impairment: Use with caution in people with severe liver dysfunction; in cirrhosis, avoid electrolyte and acid/base imbalances that might lead to hepatic encephalopathy.
Kidney failure: combined triamterene and indomethacin therapy caused reversible acute kidney injury in some people. [3]
Kidney stones: Use with caution in people with kidney stones.
Use should be avoided if the creatinine clearance is less than 10 ml/minute.
Triamterene directly blocks the epithelial sodium channel [4] (ENaC) on the lumen side of the kidney collecting tubule. [5] : 127 Other diuretics cause a decrease in the sodium concentration of the forming urine due to the entry of sodium into the cell via the ENaC, and the concomitant exit of potassium from the principal cell into the forming urine. Blocking ENaC prevents this from happening. Amiloride works in the same way. Sodium channel blockers directly inhibit the entry of sodium into the sodium channels.
Triamterene is commonly prepared in combination with hydrochlorothiazide for treatment of hypertension (high blood pressure) and edema (water retention). This combination is in a class of medications called diuretics or 'water pills', and causes the kidneys to get rid of the body's unneeded water and sodium through the urine. [6]
The triamterene ring system is found in many naturally occurring compounds, such as folic acid and riboflavin. The observation that the naturally occurring compound xanthopterin had renal affects led scientists at Smith Kline and French Laboratories in Philadelphia to begin a medicinal chemistry campaign to discover potential drugs, as part of a program to discover potassium-sparing diuretics. [5] : 125 The first clinical studies were published in 1961 and the first trials combining it with hydrochlorothiazide were published the next year. [5] : 126 [7] [8]
Smith Kline & French launched it as a single agent under the brand Dyrenium in 1964. [9] : 83 The combination drug with hydrochlorothiazide, Dyazide, was first approved in the US in 1965 and the first generic, brought by Bolar Pharmaceutical Co., was approved in 1987. [10] [11] In 1986 Dyazide was the most prescribed drug in the US and had $325 million in sales, making it SmithKline Beckman's second-biggest seller behind Tagamet. [11]
The patents had expired on Dyazide in 1980, but complications arose with the introductions of generics, because the formulation of Dyazide resulted in variable batches that made it impossible for generic manufacturers to show that their versions were bioequivalent. [12] [13]
Bolar Pharmaceutical was in the running to be the first to bring a generic, but its application was delayed by these concerns about whether its formulation provided the same amount of each drug; these were complicated by accusations that Bolar had fraudulently substituted Dyazide for its own version to conduct studies that were submitted to the FDA. [11] Shortly after Bolar's generic was approved, further concerns were raised with regard to Bolar's applications to market generics more generally; these findings among others raised widespread concern among doctors and the public over whether generics were really the same as branded drugs. [14] [15] Bolar ended up recalling its generic form of Dyazide and withdrawing the product in 1990. [16] In 1991 the US Justice Department on behalf of the FDA filed 20 criminal charges against Bolar for its fraud, [17] and early the next year Bolar pled guilty and agreed to pay a $10M fine. [18] Public concern over the safety of generic drugs was further exacerbated by a Congressional investigation into bribery at the FDA by generics companies that found pervasive corruption; the investigation had been spurred by the generics company Mylan, which had hired private investigators based on its beliefs that competitors were getting unfair advantages in getting their generics approved. [19]
Mylan itself developed a version of a triamterene/hydrochlorothiazide combination drug after the Dyazide patent expired, and used a different, more stable formulation [13] as well as different dosages of each active ingredient (50 mg hydrochlorothiazide and 75 mg triamterene, compared with Dyazide's 25 mg hydrochlorothiazide and 50 mg triamterene) so it had to get approval as a new drug, as opposed to a generic; their product was called Maxzide and was approved in 1984. [20] [21] The higher dose allowed once per day dosing, which Mylan and its marketing partner, Lederle, believed would help it compete against Dyazide, which had $210M in sales in 1983. [21]
Mylan's patents on the drug were declared invalid in court, and its marketing exclusivity expired in 1987, prompting a rush of generic competition and litigation by two of them, American Therapeutics Inc. and Vitarine Pharmaceuticals, with the FDA. [22] Vitarine, along with Par Pharmaceutical, were two of the companies that Mylan had targeted in its investigation into corruption and it turned out that Par and Vitarine had each used Mylan's Maxzide to obtain its bioequivalence data, leading both companies to withdraw its generic competitor to Mylan's product. [19] [23] Generics eventually entered the market. [24]
While there is a lack of randomized controlled trials evaluating the use of triamterene in the treatment of Ménière's disease, the typical treatment is 37.5 mg of triamterene with 25 mg of hydrochlorothiazide 1–2 capsules daily. [25] [26] This recommendation was given a Strength of Recommendation Taxonomy (SORT) grade of C.[ citation needed ]
Furosemide, sold under the brand name Lasix among others, is a loop diuretic medication used to treat edema due to heart failure, liver scarring, or kidney disease. Furosemide may also be used for the treatment of high blood pressure. It can be taken intravenously or orally. When given intravenously, furosemide typically takes effect within five minutes; when taken orally, it typically metabolizes within an hour.
Hydrochlorothiazide, sold under the brand name Hydrodiuril among others, is a diuretic medication used to treat hypertension and swelling due to fluid build-up. Other uses include treating diabetes insipidus and renal tubular acidosis and to decrease the risk of kidney stones in those with a high calcium level in the urine. Hydrochlorothiazide is taken by mouth and may be combined with other blood pressure medications as a single pill to increase effectiveness. Hydrochlorothiazide is a thiazide medication which inhibits reabsorption of sodium and chloride ions from the distal convoluted tubules of the kidneys, causing a natriuresis. This initially increases urine volume and lowers blood volume. It is believed to reduce peripheral vascular resistance.
Irbesartan, sold under the brand name Aprovel among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It is a reasonable initial treatment for high blood pressure. It is taken by mouth. Versions are available as the combination irbesartan/hydrochlorothiazide.
Amiloride, sold under the trade name Midamor among others, is a medication typically used with other medications to treat high blood pressure or swelling due to heart failure or cirrhosis of the liver. Amiloride is classified as a potassium-sparing diuretic. Amiloride is often used together with another diuretic, such as a thiazide or loop diuretic. It is taken by mouth. Onset of action is about two hours and it lasts for about a day.
Chlortalidone, also known as chlorthalidone, is a thiazide-like diuretic drug used to treat high blood pressure, swelling, diabetes insipidus, and renal tubular acidosis. Because chlortalidone is effective in most patients with high blood pressure, it is considered a preferred initial treatment. It is also used to prevent calcium-based kidney stones. It is taken by mouth. Effects generally begin within three hours and last for up to three days. Long-term treatment with chlortalidone is more effective than hydrochlorothiazide for prevention of heart attack or stroke.
Thiazide refers to both a class of sulfur-containing organic molecules and a class of diuretics based on the chemical structure of benzothiadiazine. The thiazide drug class was discovered and developed at Merck and Co. in the 1950s. The first approved drug of this class, chlorothiazide, was marketed under the trade name Diuril beginning in 1958. In most countries, thiazides are the least expensive antihypertensive drugs available.
Lisinopril is a medication belonging to the drug class of angiotensin-converting enzyme (ACE) inhibitors and is used to treat hypertension, heart failure, and heart attacks. For high blood pressure it is usually a first-line treatment. It is also used to prevent kidney problems in people with diabetes mellitus. Lisinopril is taken orally. Full effect may take up to four weeks to occur.
Conivaptan, sold under the brand name Vaprisol, is a non-peptide inhibitor of the receptor for anti-diuretic hormone, also called vasopressin. It was approved in 2004 for hyponatremia. The compound was discovered by Astellas and marked in 2006. The drug is now marketed by Cumberland Pharmaceuticals, Inc.
Potassium-sparing diuretics or antikaliuretics refer to drugs that cause diuresis without causing potassium loss in the urine. They are typically used as an adjunct in management of hypertension, cirrhosis, and congestive heart failure. The steroidal aldosterone antagonists can also be used for treatment of primary hyperaldosteronism. Spironolactone, a steroidal aldosterone antagonist, is also used in management of female hirsutism and acne from PCOS or other causes.
Losartan, sold under the brand name Cozaar among others, is a medication used to treat high blood pressure (hypertension). It is in the angiotensin receptor blocker (ARB) family of medication, and is considered protective of the kidneys. Besides hypertension, it is also used in diabetic kidney disease, heart failure, and left ventricular enlargement. It comes as a tablet that is taken by mouth. It may be used alone or in addition to other blood pressure medication. Up to six weeks may be required for the full effects to occur.
Valsartan, sold under the brand name Diovan among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It belongs to a class of medications referred to as angiotensin II receptor blockers (ARBs). It is a reasonable initial treatment for high blood pressure. It is taken by mouth.
Mylan N.V. was a global generic and specialty pharmaceuticals company. In November 2020, Mylan merged with Upjohn, Pfizer's off-patent medicine division, to form Viatris. Previously, the company was domiciled in the Netherlands, with principal executive offices in Hatfield, Hertfordshire, UK and a "Global Center" in Canonsburg, Pennsylvania, US.
Atenolol/chlorthalidone, also known as co-tenidone, is a combination medication used to treat high blood pressure. It is made up of atenolol, a beta-blocker and chlortalidone, a diuretic. It is not recommended as an initial treatment but may be used in those who are taking atenolol and chlortalidone individually. It is taken by mouth.
Metolazone is a thiazide-like diuretic marketed under the brand names Zytanix, Metoz, Zaroxolyn, and Mykrox. It is primarily used to treat congestive heart failure and high blood pressure. Metolazone indirectly decreases the amount of water reabsorbed into the bloodstream by the kidney, so that blood volume decreases and urine volume increases. This lowers blood pressure and prevents excess fluid accumulation in heart failure. Metolazone is sometimes used together with loop diuretics such as furosemide or bumetanide, but these highly effective combinations can lead to dehydration and electrolyte abnormalities.
Dapagliflozin, sold under the brand names Farxiga (US) and Forxiga (EU) among others, is a medication used to treat type 2 diabetes. It is also used to treat adults with heart failure and chronic kidney disease. It reversibly inhibits sodium-glucose co-transporter 2 (SGLT-2) in the renal proximal convoluted tubule to reduce glucose reabsorption and increase urinary glucose excretion.
Meclofenamic acid is a drug used for joint, muscular pain, arthritis and dysmenorrhea. It is a member of the anthranilic acid derivatives class of nonsteroidal anti-inflammatory drugs (NSAIDs) and was approved by the US FDA in 1980. Like other members of the class, it is a cyclooxygenase (COX) inhibitor, preventing the formation of prostaglandins.
Telmisartan/hydrochlorothiazide, sold under the brand name Micardis HCT among others, is a fixed-dose combination medication used to treat high blood pressure. It is a combination of telmisartan an angiotensin II receptor antagonist with hydrochlorothiazide a diuretic. It may be used if telmisartan by itself is not sufficient. It is taken by mouth.
Valsartan/hydrochlorothiazide, sold under the brand name Diovan HCT among others, is a medication used to treat high blood pressure when valsartan is not sufficient. It is a combination of valsartan, an angiotensin receptor blocker with hydrochlorothiazide, a diuretic. It is taken by mouth.
An ACE inhibitor and thiazide combination is a drug combination used to treat hypertension. They are given by mouth. ACE inhibitors reduce the activity of angiotensin-converting enzyme (ACE) which produces angiotensin II, a hormone that constricts blood vessels. Thiazides are a class of diuretics that inhibit the thiazide receptor, thereby increasing urine production and reducing excess water and salt in the body. Several organizations recommend combination therapy for hypertension in cases of failure of a single drug to achieve target blood pressure, or even as a first line treatment for some patients.
Hydrochlorothiazide/triamterene, also known as co-triamterzide, is a fixed-dose combination medication of hydrochlorothiazide and triamterene. It is used to treat high blood pressure and edema (swelling). Specifically it is used in those who develop low blood potassium (hypokalemia) when on only hydrochlorothiazide. It is taken by mouth.