Triamterene is an oral diuretic used medically to treat edema. Edema may occur without known cause (idiopathic edema) or be associated with liver or kidney disease, congestive heart failure, corticosteroid/progestin use, or the overproduction of aldosterone. Triamterene is classified as a potassium-sparing diuretic, increasing the rate of water and sodium excretion but preserving potassium levels. As the name suggests, this drug produces a pronounced diuretic effect without the potassium loss associated with thiazides/loop diuretics. The need for potassium supplementation is, therefore, eliminated with this agent. The diuretic activity following a single dose of triamterene is usually evident within 2 to 4 hours, reaching a peak effect at approximately 3 hours in most cases. Its diuretic effect lasts for a total of 7-9 hours following administration.
Triamterene is utilized (off-label) by bodybuilders and athletes to shed subcutaneous water prior to a bodybuilding competition or to make weight class adjustments in certain competitive sports. Bodybuilders, in particular, rely heavily on the increased definition that can result when water retention is reduced. The highly defined “shredded” physique common to bodybuilding today is nearly impossible to achieve without the use of diuretics. At the same time, diuretics are the reason weight class competitors like wrestlers and boxers often appear much heavier during an event than they do at the weigh-in. A considerable amount of body weight (in the form of water) can be removed with diuretic use, often resulting in a drop of one or more weight categories. This practice is very common in sports where the user is not drug tested and has ample time to rehydrate following a weigh-in, resulting in the athlete competing at a significantly heavier weight than his or her weight class would dictate.
Triamterene first saw extensive clinical use during the 1960s. It was used largely as a standalone agent at first but went on to become a widely used agent in clinical medicine in combination products with other diuretic drugs. Today this usually includes other, more potent diuretics like thiazides and loop agents. Here, the potassium loss of the stronger diuretic is balanced to some degree by the potassium-sparing triamterene, which often results in a reduced or even eliminated need for potassium supplementation during therapy. Single-ingredient preparations of triamterene are still sold, however, and can be found in several countries including Belgium (Dytac), United Kingdom (Dytac), and the United States (Dyrenium).
Triamterene is most commonly supplied in capsules of 50 mg and 100 mg.
Triamterene is a potassium-sparing diuretic. It has the chemical designation 2,4,7-triamino-6-phenyl-pteridine.
Warnings (Dehydration, Death)
The misuse of the diuretic drug(s) for physique- or performance-enhancing purposes is characterized as a high-risk practice. Diuretics may produce a life-threatening level of dehydration and electrolyte imbalance when administered without proper medical supervision. Many deaths have been associated with the misuse of these drugs. It is also important to note that the supplementation of potassium, either through pharmaceuticals or a diet rich in potassium, is generally not advised while taking a potassium-sparing diuretic like triamterene. Excessive potassium intake may cause hyperkalemia, which may lead to cardiac irregularities and possibly death.
Triamterene use may be associated with electrolyte imbalance, including elevated or decreased potassium levels. Signs of electrolyte imbalance include dry mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pain, muscle cramping, seizures, reduced urine volume, low blood pressure, and gastrointestinal disturbances. Other side effects may include nausea, vomiting, jaundice, blood platelet deficiency, anemia, azotemia (buildup of metabolic waste products in the blood), renal stones, and other kidney disturbances. Additionally, some rare side effects characterized as hypersensitivity reactions have been reported including skin rash, photosensitivity, and anaphylaxis (an extreme and potentially life-threatening allergic reaction).
When used medically to treat hypertension, the usual initial dosage in adults is 100 mg twice daily after meals (200 mg per day)¹. This may be increased, but should never exceed 300 mg per day in total. Among bodybuilders, this drug is commonly used for only a few days prior to a competition, adjusting the dosage over the course to elicit the best level of diuretic effect. Since it has a long-lasting action, it is generally administered once per day. One capsule (100 mg) is usually taken the first thing in the morning with a meal, and the effect judged over the next several hours. The dosage is usually increased by one capsule per day for 2-3 days at most until the user is noticing the proper water loss for competition. When looking for a stronger diuretic effect, many bodybuilders and athletes will opt to combine triamterene with another stronger diuretic such as hydrochlorothiazide or furosemide. The dosage of both agents would be adjusted downward to compensate for their combined effects. The goal here is usually to increase short-term diuresis, without causing the extreme potassium loss that can be associated with the use of thiazides or loop diuretics alone at higher doses.
Triamterene is widely sold throughout the developed world. Although single-ingredient preparations containing triamterene are available, this drug is most commonly sold in multi-ingredient preparations targeting edema and/or high blood pressure. Low cost, modest demand, and high availability make this drug a low-profit target for counterfeiting.