From the Guidelines
Triamterene can cause significant side effects, particularly hyperkalemia, and its use should be carefully monitored, especially in patients with chronic kidney disease (CKD) or those taking other medications that affect potassium levels 1. When considering the side effects of triamterene, it is essential to prioritize morbidity, mortality, and quality of life as outcomes. The medication can lead to various adverse effects, including:
- Electrolyte imbalances, such as hyperkalemia, which can cause irregular heartbeat, muscle weakness, or numbness
- Photosensitivity, skin rash, or allergic reactions
- Kidney stones due to triamterene's tendency to crystallize in urine
- Rarely, blood disorders or liver problems can occur
- Effects on blood sugar levels and potential worsening of gout due to increased uric acid levels It is crucial to monitor patients taking triamterene regularly, with measurements of serum creatinine and potassium every 5-7 days after initiation of treatment until the values are stable, and then every 3-6 months 1. The use of triamterene should be approached with caution, especially in patients with CKD, as it can exacerbate existing kidney problems. The most recent and highest quality study recommends avoiding triamterene in patients with significant CKD (eg, GFR <45 mL/min) 1.
From the FDA Drug Label
Triamterene has been reported in renal stones in association with other calculus components. Hyperkalemia will rarely occur in patients with adequate urinary output, but it is a possibility if large doses are used for considerable periods of time. Triamterene may cause a decreasing alkali reserve, with the possibility of metabolic acidosis. Triamterene has elevated uric acid, especially in persons predisposed to gouty arthritis In the event of overdosage, it can be theorized that electrolyte imbalance would be the major concern, with particular attention to possible hyperkalemia.
The side effects of Triamterene include:
- Hyperkalemia: a possibility if large doses are used for considerable periods of time 2
- Renal stones: in association with other calculus components 2
- Metabolic acidosis: due to a decreasing alkali reserve 2
- Gouty arthritis: elevated uric acid, especially in persons predisposed to gouty arthritis 2
- Electrolyte imbalance: in the event of overdosage, with particular attention to possible hyperkalemia 2
- Nausea and vomiting: other G.I. disturbances and weakness in the event of overdosage 2
From the Research
Triamterene HCl Side Effects
- Hyperkalemia is a known side effect of triamterene, especially in patients with diabetes mellitus and the elderly 3
- The frequency of hyperkalemia in patients taking triamterene-hydrochlorothiazide combination is 0.59% in nondiabetics and 1.08% in diabetics 3
- Hypokalemia can also occur with a frequency of about 5% and is not influenced by age or diabetes 3
- Clinically significant hyperkalemia or hypokalemia did not develop in patients taking Maxzide tablets (75 mg triamterene/50 mg hydrochlorothiazide) 4
- Adverse events, possibly related to study medication, were reported by 46% of patients taking hydrochlorothiazide/triamterene alone and 24% of patients taking diltiazem alone 5
- A randomized clinical trial found no significant differences in weight changes, input-to-output changes, and other secondary outcomes between patients taking triamterene plus hydrochlorothiazide and those taking hydrochlorothiazide alone 6
Specific Patient Populations
- Elderly patients are more likely to develop hyperkalemia when taking triamterene-hydrochlorothiazide combination 3
- Patients with diabetes mellitus are also at increased risk of developing hyperkalemia when taking triamterene-hydrochlorothiazide combination 3
- Patients with heart failure and diuretic resistance did not show significant improvement in outcomes with the addition of triamterene to standard treatment 6
Monitoring and Precautions
- Renal function and serum potassium concentration should be assessed prior to instituting treatment and repeated within a few days and a few weeks thereafter in patients at risk, especially when renal function is suspected, and in the elderly 3