From the Guidelines
Chlorthalidone has not been established to increase melanoma risk based on current evidence. Patients taking this thiazide-like diuretic for hypertension can continue using it without specific concerns about melanoma development. While some studies have examined associations between thiazide diuretics and skin cancers, the evidence specifically linking chlorthalidone to melanoma is limited and inconclusive 1. Chlorthalidone works by increasing sodium and water excretion through inhibition of sodium reabsorption in the distal tubules of the kidneys, which helps lower blood pressure. The typical dosing ranges from 12.5 to 25 mg daily, with some patients requiring up to 50 mg for adequate blood pressure control. As with any medication, patients should practice routine skin protection measures including regular use of sunscreen, wearing protective clothing, and undergoing periodic skin examinations, particularly if they have other risk factors for skin cancer. These precautions are prudent regardless of medication use, as they help reduce overall skin cancer risk. Some key points to consider when prescribing chlorthalidone include:
- Monitoring for hyponatremia and hypokalemia, uric acid and calcium levels 1
- Being aware of the potential for hypokalemia, especially when compared to other thiazide-like diuretics like hydrochlorothiazide 1
- Considering the use of potassium-sparing antihypertensives to modify the risk of hypokalemia 1 It's essential to weigh the benefits and risks of chlorthalidone, considering the latest evidence, to make informed decisions about its use in patients with hypertension. The most recent and highest quality study on this topic is from 2021 1, which provides valuable insights into the adverse effects of medications on micronutrient status.
From the Research
Risk of Melanoma Associated with Chlorthalidone
- The risk of melanoma associated with Chlorthalidone, a thiazide-like diuretic, is not directly stated in the provided studies, but we can look at the associations between thiazide diuretics and melanoma risk.
- A study published in 2022 2 found that thiazide diuretic users had a higher risk of malignant melanoma, with a pooled adjusted odds ratio of 1.10 (95% CI, 1.04−1.15).
- Another study published in 2021 3 found that long-term use of indapamide, a thiazide-like diuretic, was associated with an increased incidence of cutaneous malignant melanoma (IRR 1.43; 95% CI 1.35-1.50).
- A nationwide nested case-control study published in 2023 4 found a slightly increased melanoma risk in users of diuretics (RR 1.08, CI 1.01-1.15), but the association was weak and lacked a dose-response relationship.
- A systematic review and meta-analysis published in 2024 5 found increased risks of melanoma with thiazides (RR = 1.09,95% CI = 1.02-1.17) and diuretics (RR = 1.06,95% CI = 1.03-1.10).
- A study published in 2021 6 found a small increase in risk of melanoma associated with high use of hydrochlorothiazide (OR = 1.11,95% CI 1.00-1.23), but the risk was more elevated for the lentigo subtype (OR = 1.57,95% CI 1.01-2.42).
Key Findings
- Thiazide diuretics, including Chlorthalidone, may be associated with an increased risk of melanoma.
- The risk of melanoma associated with Chlorthalidone is not directly stated in the provided studies, but the associations between thiazide diuretics and melanoma risk suggest a potential increased risk.
- The quality of evidence is generally low or very low, and more research is needed to confirm the associations between antihypertensives and skin cancer risk.