Study to Evaluate the Influence of Hydrochlorothiazide on Dermal Photosensitivity and DNA Stability - a Pilot Study (HCTox Study)

NCT04654312 | Completed Phase 1

• 1 other identifier: HCTox
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The clinical trial is designed as a national, prospective, single-center, double-blind, parallel group, randomized, controlled, interventional trial to investigate whether a therapy with HCT compared with placebo can affect dermal photosensitivity and DNA stability.

Conditions

Photosensitivity

Outcome Measures

Primary Outcomes (2)

• Changes in subjects´ minimal-erythema-dose (MED).

  The MED is the minimal erythema dose, meaning the minimal dose of energy (in this case provided by UV-exposition) per area that leads to a clinically visible skin reaction, mainly a slight reddening. The MED is assessed by a clinical tool called the light-stair.

  2 weeks

• Amount of excretion of pyrimidine-dimers (PD) in urine.

  Changes from Baseline Visit to Day 26

  26 days

Secondary Outcomes (2)

• Changes in blood-serum vitamin-D levels.

  26 days

• Changes in blood pressure.

  26 days

Other Outcomes (3)

• Changes in electrolytes (Na+, K+)

  26 days

• Changes in kidney function (eGFR)

  26 days

• Changes in blood count

  26 days

Study Arms (2)

Intervention

EXPERIMENTAL

Intake of HCT 25 mg, 1 tablet/d for 15 days

Drug: Hydrochlorothiazide

Placebo

PLACEBO COMPARATOR

Intake of Placebo, 1 tablet/d for 15 days

Drug: Placebo

Interventions

Hydrochlorothiazide DRUG

Please see arm descriptions

Also known as: HCT

Intervention

Placebo DRUG

Please see arm descriptions

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• The subject is willing and able to participate and provides written informed consent;
• Healthy subjects with no concomitant medical conditions;
• Age ≥ 18 years;
• The subject is willing to take HCT 25 mg a day although not clinically indicated;
• The subject is willing to undergo controlled UV-exposition although not clinically indicated;
• Skin type I - IV.

You may not qualify if:

• History of any cardiac disease;
• History of any dermatologic disease;
• Renal insufficiency (eGFR \<60 ml/min/1.73m²);
• Intake of photosensitive substances, especially intake of HCT;
• Frequent, above-average, UV exposition (naturally or artificially);
• Known hypertension;
• Known electrolyte disbalance;
• Systolic blood pressure at baseline \<100 mmHg;
• Skin type V and VI;
• History of severe diseases, which could endanger the safety of study participant;
• Known unresolved history of alcohol dependency or drug abuse or any other kind of dependencies
• Intake of any of the following medications or substances: Betablockers; nitrates; barbiturates; phenothiazines; tricyclic antidepressants; vasodilatory drugs; ACE-inhibitors; NSAIDs; salicylates; phenytoin; Insulin; oral antidiabetic drugs; vasoconstrictors; glycosides; substances lowering blood-urea levels; substances causing a Long-QT-Syndrome; chinidine; carbamazepine; cyclosporine; cholecalciferol; potassium salts; amantadine; allopurinol; methyldopa; cholestyramine; colestipol; other diuretics; lithium; cytostatic drugs;
• Women in childbearing age and not using medically acceptable effective contraception refer to CTFG: The study population includes female of childbearing potential. Female of childbearing potential have to agree to comply with the applicable contraceptive requirements of the protocol for the duration of the study or having post-menopausal status or be permanently sterilized (at least 6 weeks post-sterilization). Highly effective contraception is defined as a contraceptive method with failure rate of less than 1 % per year when used consistently and correctly and when applicable, in accordance with the product label;
• Subject is pregnant (e.g., positive ß-hCG test) or is breast feeding;
• Hypersensitivity to the active substance, to HCT or any of its excipients.

Sponsors & Collaborators

• Universität des Saarlandes: lead

Study Sites (1)

Saarland University Hospital

Homburg, Saarland, 66421, Germany

Location

Related Publications (1)

• Gotzinger F, Hohl M, Lauder L, Millenaar D, Kunz M, Meyer MR, Ukena C, Lerche CM, Philipsen PA, Reichrath J, Bohm M, Mahfoud F. A randomized, placebo-controlled, trial to assess the photosensitizing, phototoxic and carcinogenic potential of hydrochlorothiazide in healthy volunteers. J Hypertens. 2023 Nov 1;41(11):1853-1862. doi: 10.1097/HJH.0000000000003558. Epub 2023 Sep 13.

  PMID: 37702559 RESULT

Related Links

• Hydrochlorothiazid - Risiko von nichtmelanozytärem Hautkrebs \[Basalzellkarzinom (Basaliom); Plattenepithelkarzinom der Haut (Spinaliom): Rote-Hand-Brief vom 17. Oktober 2018.

MeSH Terms

Conditions

Photosensitivity Disorders

Interventions

Hydrochlorothiazide

Condition Hierarchy (Ancestors)

Skin Diseases; Skin and Connective Tissue Diseases

Intervention Hierarchy (Ancestors)

Chlorothiazide; Benzothiadiazines; Sulfonamides; Sulfones; Sulfur Compounds; Organic Chemicals; Thiazides; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Study Officials

• Felix Mahfoud, MD

  Saarland University Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: National, prospective, single-center, double-blind, parallel group, randomized, controlled, interventional Trial.

Study Record Dates

• First Submitted: November 24, 2020
• First Posted: December 4, 2020
• Study Start: January 18, 2021
• Primary Completion: July 22, 2021
• Study Completion: July 22, 2021
• Last Updated: August 11, 2025

Record last verified: 2021-07

Data Sharing

• IPD Sharing: Will not share

Locations

DE (1)