Triamterene and Hydrochlorothiazide side effects: what 6,106 FDA adverse event reports show
Drug class
Potassium-sparing Diuretic
Label matched
Triamterene (Triamterene)
Who reports
6,106 reports · 54% serious · 352 with death outcome · 73% female
Used for
Triamterene capsules are indicated in the treatment of edema associated with congestive heart failure, cirrhosis of the liver and the nephrotic syndrome; steroid-induced edema, idiopathic edema and edema due to secondary hyperaldosteronism. Triamterene capsules may be used alone or with other diuretics, either for its added diuretic effect or its potassium-sparing potential.
Boxed warning
Abnormal elevation of serum potassium levels (greater than or equal to 5.5 mEq/liter) can occur with all potassium-sparing agents, including triamterene capsules. Hyperkalemia is more likely to occur in patients with renal impairment and diabetes (even without evidence of renal impairment), and in the elderly or severely ill.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 496 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Sleep apnoea syndrome | 36 | 6.5 4.7–9.0ROR 6.5 · χ² 161 / p 4e-37 | 6.0 EB05 4.5 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 7.7 | no trial data cached |
| Blood potassium decreased | 54 | 6.2 4.7–8.0ROR 6.2 · χ² 229 / p 6e-52 | 5.9 EB05 4.7 · IC025 +2.1 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 6.6 | no trial data cached |
| Nerve compression | 16 | 6.0 3.7–9.7ROR 6.0 · χ² 61 / p 3e-15 | 5.2 EB05 3.4 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Hair texture abnormal | 23 | 5.9 3.9–8.8ROR 5.9 · χ² 88 / p 4e-21 | 5.3 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious n=6 · ♀ 100% (drug 73%) | no trial data cached |
| Hair colour changes | 21 | 5.7 3.7–8.8ROR 5.8 · χ² 77 / p 7e-19 | 5.1 EB05 3.5 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious n=5 | no trial data cached |
| Glomerular filtration rate decreased | 19 | 5.4 3.4–8.4ROR 5.4 · χ² 64 / p 8e-16 | 4.8 EB05 3.3 · IC025 +1.5 3/3 methods agree | Lab value / disease marker | serious PRR 5.9 | no trial data cached |
| Blood urea increased | 26 | 5.3 3.6–7.8ROR 5.3 · χ² 87 / p 7e-21 | 4.9 EB05 3.5 · IC025 +1.6 3/3 methods agree | Lab value / disease marker | serious PRR 4.8 | no trial data cached |
| Anorexia | 20 | 5.3 3.4–8.1ROR 5.3 · χ² 65 / p 4e-16 | 4.7 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.5 | no trial data cached |
| Renal failure acute | 64 | 5.1 4.0–6.5ROR 5.2 · χ² 208 / p 2e-47 | 4.9 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.4 · ♀ 46% (drug 73%) | no trial data cached |
| Activities of daily living impaired | 29 | 5.0 3.4–7.1ROR 5.0 · χ² 88 / p 4e-21 | 4.6 EB05 3.4 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 | no trial data cached |
| Hyponatraemia (low sodium) | 76 | 4.6 3.7–5.8ROR 4.7 · χ² 214 / p 9e-49 | 4.5 EB05 3.7 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Blood sodium decreased | 25 | 4.6 3.1–6.8ROR 4.6 · χ² 66 / p 2e-16 | 4.2 EB05 3.0 · IC025 +1.4 3/3 methods agree | Lab value / disease marker | serious PRR 5.3 | no trial data cached |
| Bursitis | 16 | 4.6 2.8–7.4ROR 4.6 · χ² 41 / p 8e-11 | 4.1 EB05 2.7 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| Micturition urgency | 15 | 4.5 2.7–7.5ROR 4.6 · χ² 38 / p 4e-10 | 4.0 EB05 2.6 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Osteopenia | 20 | 4.5 2.9–7.0ROR 4.5 · χ² 51 / p 5e-13 | 4.1 EB05 2.8 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 | no trial data cached |
| Oedema peripheral (swelling of legs/feet) | 159 | 4.5 3.8–5.2ROR 4.6 · χ² 426 / p 6e-95 | 4.4 EB05 3.9 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Nephropathy | 12 | 4.4 2.5–7.7ROR 4.4 · χ² 28 / p 6e-8 | 3.8 EB05 2.4 · IC025 +1.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 5.0 | no trial data cached |
| Pharmaceutical product complaint | 33 | 4.3 3.1–6.0ROR 4.3 · χ² 80 / p 2e-19 | 4.1 EB05 3.0 · IC025 +1.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 3.6 | no trial data cached |
| Hyperlipidaemia | 15 | 4.3 2.6–7.1ROR 4.3 · χ² 35 / p 2e-9 | 3.8 EB05 2.5 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 | no trial data cached |
| Chronic kidney disease | 95 | 4.3 3.5–5.2ROR 4.3 · χ² 234 / p 4e-53 | 4.2 EB05 3.5 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.6 | no trial data cached |
| Hiatus hernia | 16 | 4.2 2.6–6.9ROR 4.2 · χ² 36 / p 8e-10 | 3.8 EB05 2.5 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Heart rate irregular | 28 | 4.2 2.9–6.1ROR 4.2 · χ² 66 / p 2e-16 | 4.0 EB05 2.9 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 · 73% consumer | no trial data cached |
| Cardiomegaly | 15 | 4.2 2.5–6.9ROR 4.2 · χ² 33 / p 5e-9 | 3.7 EB05 2.4 · IC025 +1.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 4.5 | no trial data cached |
| Ventricular tachycardia | 20 | 4.1 2.7–6.4ROR 4.2 · χ² 45 / p 1e-11 | 3.8 EB05 2.6 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 | no trial data cached |
| Seasonal allergy | 17 | 4.1 2.6–6.7ROR 4.1 · χ² 37 / p 5e-10 | 3.8 EB05 2.5 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious n=7 | no trial data cached |
| Hypokalaemia (low potassium) | 55 | 4.1 3.2–5.4ROR 4.1 · χ² 127 / p 1e-29 | 4.0 EB05 3.2 · IC025 +1.6 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 3.9 | no trial data cached |
| Flank pain | 11 | 4.0 2.2–7.3ROR 4.0 · χ² 22 / p 1e-6 | 3.5 EB05 2.1 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Gout | 21 | 4.0 2.6–6.2ROR 4.0 · χ² 45 / p 1e-11 | 3.7 EB05 2.6 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 · ♀ 38% (drug 73%) | no trial data cached |
| Economic problem | 18 | 4.0 2.5–6.4ROR 4.0 · χ² 38 / p 4e-10 | 3.7 EB05 2.5 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 4.4 | no trial data cached |
| Injection site haematoma | 17 | 4.0 2.5–6.4ROR 4.0 · χ² 35 / p 2e-9 | 3.6 EB05 2.4 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious n=4 | no trial data cached |
| Osteoarthritis | 49 | 4.0 3.0–5.2ROR 4.0 · χ² 106 / p 4e-25 | 3.8 EB05 3.0 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Laceration | 11 | 4.0 2.2–7.2ROR 4.0 · χ² 21 / p 2e-6 | 3.5 EB05 2.1 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious n=9 | no trial data cached |
| Cholecystectomy | 13 | 3.9 2.3–6.8ROR 3.9 · χ² 26 / p 2e-7 | 3.5 EB05 2.2 · IC025 +0.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 | no trial data cached |
| Madarosis | 13 | 3.8 2.2–6.6ROR 3.8 · χ² 24 / p 4e-7 | 3.4 EB05 2.2 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Blood iron decreased | 13 | 3.8 2.2–6.5ROR 3.8 · χ² 24 / p 5e-7 | 3.4 EB05 2.1 · IC025 +0.8 3/3 methods agree | Lab value / disease marker | serious PRR 3.8 | no trial data cached |
| Dry mouth | 87 | 3.7 3.0–4.5ROR 3.7 · χ² 168 / p 8e-39 | 3.6 EB05 3.0 · IC025 +1.5 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 3.2 · 70% consumer | no trial data cached |
| Nocturia (night-time urination) | 13 | 3.7 2.1–6.3ROR 3.7 · χ² 23 / p 9e-7 | 3.3 EB05 2.1 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 | no trial data cached |
| Fibromyalgia | 26 | 3.7 2.5–5.4ROR 3.7 · χ² 48 / p 2e-12 | 3.5 EB05 2.5 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Obesity | 17 | 3.7 2.3–5.9ROR 3.7 · χ² 30 / p 2e-8 | 3.4 EB05 2.2 · IC025 +0.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.2 | no trial data cached |
| Coronary artery disease | 32 | 3.6 2.5–5.1ROR 3.6 · χ² 58 / p 2e-14 | 3.4 EB05 2.6 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 · ♀ 42% (drug 73%) | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Nausea | 407 | 1.8 1.6–1.9ROR 1.8 · χ² 141 / p 8e-33 | 1.8 EB05 1.6 · IC025 +0.7 | Labeled — boxed warning exact term | serious PRR 1.9 | no trial data cached |
| Fatigue (tiredness) | 400 | 1.8 1.6–1.9ROR 1.8 · χ² 138 / p 4e-32 | 1.8 EB05 1.6 · IC025 +0.7 | Labeled — boxed warning exact term | serious PRR 2.0 | no trial data cached |
| Pain | 328 | 1.8 1.6–2.0ROR 1.9 · χ² 126 / p 1e-29 | 1.8 EB05 1.7 · IC025 +0.7 | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Dizziness | 317 | 2.2 2.0–2.4ROR 2.3 · χ² 208 / p 2e-47 | 2.2 EB05 2.0 · IC025 +0.9 | Labeled — boxed warning exact term | serious PRR 2.4 | no trial data cached |
| Headache | 290 | 1.6 1.4–1.8ROR 1.6 · χ² 65 / p 4e-16 | 1.6 EB05 1.4 · IC025 +0.5 | Labeled — boxed warning exact term | serious PRR 1.7 | no trial data cached |
| Dyspnoea (shortness of breath) | 286 | 1.7 1.6–1.9ROR 1.8 · χ² 91 / p 8e-22 | 1.7 EB05 1.6 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.7 | no trial data cached |
| Asthenia (weakness) | 252 | 2.3 2.0–2.6ROR 2.4 · χ² 187 / p 6e-43 | 2.3 EB05 2.1 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 2.5 | no trial data cached |
| Arthralgia (joint pain) | 204 | 1.7 1.5–1.9ROR 1.7 · χ² 58 / p 1e-14 | 1.7 EB05 1.5 · IC025 +0.5 | Not in label — unassessed | serious PRR 2.0 | no trial data cached |
| Fall | 200 | 2.1 1.8–2.4ROR 2.1 · χ² 111 / p 4e-26 | 2.1 EB05 1.8 · IC025 +0.8 | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Pruritus (itching) | 195 | 1.8 1.5–2.0ROR 1.8 · χ² 66 / p 2e-16 | 1.8 EB05 1.6 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.5 | no trial data cached |
| Pain in extremity | 195 | 2.3 2.0–2.6ROR 2.3 · χ² 139 / p 2e-32 | 2.3 EB05 2.0 · IC025 +0.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 2.3 | no trial data cached |
| Weight decreased (weight loss) | 192 | 2.4 2.1–2.7ROR 2.4 · χ² 151 / p 4e-35 | 2.4 EB05 2.1 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 2.3 | no trial data cached |
| Cough | 167 | 2.0 1.8–2.4ROR 2.1 · χ² 90 / p 1e-21 | 2.0 EB05 1.8 · IC025 +0.8 | Not in label — unassessed | serious PRR 2.0 | no trial data cached |
| Muscle spasms | 159 | 3.0 2.6–3.5ROR 3.0 · χ² 208 / p 2e-47 | 3.0 EB05 2.6 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.1 · 71% consumer | no trial data cached |
| Oedema peripheral (swelling of legs/feet) | 159 | 4.5 3.8–5.2ROR 4.6 · χ² 426 / p 6e-95 | 4.4 EB05 3.9 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Sleep apnoea syndrome — n=36, PRR 6.5
- Hair texture abnormal — n=23, PRR 5.9
- Hair colour changes — n=21, PRR 5.7
- Anorexia — n=20, PRR 5.3
- Activities of daily living impaired — n=29, PRR 5.0
- Hyponatraemia — n=76, PRR 4.6
- Osteopenia — n=20, PRR 4.5
- Oedema peripheral — n=159, PRR 4.5
- Heart rate irregular — n=28, PRR 4.2
- Ventricular tachycardia — n=20, PRR 4.1
✓ A hand-written Bradford Hill causality assessment exists for this drug: Hydrochlorothiazide (thiazides) ↔ Hyponatraemia.
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Triamterene and Hydrochlorothiazide?
In FDA FAERS, the most frequently co-reported reaction terms for Triamterene and Hydrochlorothiazide are nausea, fatigue, pain, dizziness, headache, dyspnoea. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Triamterene and Hydrochlorothiazide have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: Abnormal elevation of serum potassium levels (greater than or equal to 5.5 mEq/liter) can occur with all potassium-sparing agents, including triamterene capsules. Hyperkalemia is more likely to occur in patients with renal impairment and diabetes (even without evidence of renal impairment), and in the elderly or severely ill.
Do FAERS signals prove that Triamterene and Hydrochlorothiazide causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID a09c2212-1dd5-4fbe-ad09-2a57aeabcaea, effective 20230703; matched on
openfda.generic_name.exact:"TRIAMTERENE") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 536 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.