Common blood pressure drug linked to increased skin cancer risk

by DailyHealthPost Editorial

A recent study has revealed a concerning link between the common blood pressure medication hydrochlorothiazide (HCTZ) and an increased risk of skin cancer, including malignant melanoma and lip cancer, particularly in older individuals. Experts caution against abruptly discontinuing the drug, emphasizing the need for increased awareness among prescribers and patients regarding sun protection.

Unveiling the Link: Hydrochlorothiazide and Skin Cancer

New research, including a significant study from UNSW Sydney, has established a connection between hydrochlorothiazide, a widely prescribed high blood pressure medication, and an elevated risk of certain skin cancers. The drug possesses photosensitizing properties, making the skin more susceptible to sun damage.

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Key Takeaways

  • Hydrochlorothiazide (HCTZ) has been linked to an increased risk of malignant melanoma and squamous cell carcinoma of the lip.
  • The risk for lip cancer appears to be cumulative, increasing with longer use of HCTZ.
  • HCTZ is considered the most phototoxic among common blood pressure medications.
  • Other blood pressure medications were not found to be associated with an increased skin cancer risk.
  • Despite the findings, patients should not suddenly stop taking HCTZ without consulting their doctor.

Understanding the Research

The UNSW Sydney study, based on a large data analysis of skin cancer rates among older Australians, supports similar international findings. Researchers compared HCTZ use in individuals diagnosed with lip cancer or malignant melanoma against a control group. The study accounted for variables such as other medication use and ambient ultraviolet radiation.

Another study published in the Canadian Medical Association Journal (CMAJ) by University of Toronto researchers, involving nearly a million adults aged 66 or older over two decades, found a more than 30% increased risk of melanoma among HCTZ users. While higher HCTZ exposure led to a slight increase in keratinocyte carcinoma risk (about 8%), the risk for melanoma, a more deadly form of skin cancer, significantly increased by 34%.

Expert Recommendations and Patient Guidance

Dr. Benjamin Daniels, lead author of the UNSW Sydney study, stresses that while the link is significant, patients should not abruptly stop their medication. Hypertension requires careful management, and untreated high blood pressure can lead to serious health issues like stroke and heart disease.

Healthcare professionals are advised to:

  • Consider conducting more frequent skin checks for patients on HCTZ.
  • Reinforce sun-smart behaviors, such as adequate sun protection when UV levels are high and avoiding peak UV exposure times.
  • Discuss alternative antihypertensive treatments for patients at high risk of skin cancer.

Product information for HCTZ-containing medicines has been updated to reflect this newly understood risk, aiding prescribers and patients in making informed decisions about treatment benefits and risks. The Therapeutic Goods Administration (TGA) encourages anyone with concerns to consult their healthcare professional.

Global Relevance and Future Research

While previous research from the UK, Denmark, and the USA indicated this link, the Australian study confirms its relevance in a country with one of the highest skin cancer rates globally. Researchers hope for access to more diverse data, including younger populations, to broaden their findings and further improve public health outcomes.

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Sources

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