Safety of Low-Dose Oral Minoxidil in Patients With Hypertension and Arrhythmia: A Multicenter Study of 264 Patients

Summation and recommendations for the safe and effective use of topical and oral minoxidil

BACKGROUND

Topical minoxidil, approved for the treatment of androgenetic alopecia, also has efficacy in many other hair loss disorders, its use is limited due to the need for at least daily application. Oral minoxidil, in doses below those likely to lower blood pressure (so called "low dose oral minoxidil") has increasingly been used off label to treat a variety of hair loss conditions but without any standard recommended best practices.

OBJECTIVES

To provide a review of how experts in hair loss use the available literature on topical and low dose oral minoxidil to educate and treat safely and effectively patients with hair loss.

METHODS

Dermatologists with expertise in hair disorders met by teleconference and email to review the literature and share their direct experience with topical and oral minoxidil.

RESULTS

Provision of basic knowledge of the key aspects of the use of topical or oral minoxidil to insure safe and effective use of either in treating hair loss.

High-dose Oral Minoxidil for the Treatment of Androgenetic Alopecia

Low-dose oral minoxidil (≤5mg daily) has emerged as an effective off-label treatment for androgenetic alopecia, outperforming topical minoxidil in terms of adherence. However, the optimal dose has not yet been determined, and high doses may cause systemic adverse effects. This retrospective study of 57 patients evaluated the safety and efficacy profile of oral minoxidil at higher doses (>5mg). Results showed an overall improvement in hair density between 10-30% in most patients, although with variable responses. A total of 17.5% of patients experienced significant improvements (>50%), while another 17.5% improved <10%. A quarter of the patients (24.6%) developed adverse effects, such as hypertrichosis (17.5%) and tachycardia (3.5%). Although it is a promising therapeutic option, higher doses of oral minoxidil require further studies to optimize its use and better understand its safety and efficacy profile.

Characterization and Management of Adverse Events of Low-Dose Oral Minoxidil Treatment for Alopecia: A Narrative Review

Low-dose oral minoxidil (LDOM) has emerged as a widely used off-label treatment for different types of alopecia, showing a favorable safety profile and effectiveness. Despite its growing use, it is essential to understand the possible associated adverse events (AEs) and their appropriate management to optimize this therapy. The aim of this article was to comprehensively review the AEs of LDOM treatment, describing their frequency, risk factors, affected anatomical sites, and management strategies. A search in the PubMed and EMBASE databases was performed for studies published before 31 December 2024, reporting the treatment of any type of hair loss with oral minoxidil. The most frequent AE is hypertrichosis, occurring in approximately 15% of patients, with a higher incidence in women and patients with higher doses. Fluid retention affects 1.3-10% of patients, particularly women, and typically occurs within 1-3 months of treatment. Other cardiovascular AEs, such as tachycardia or dizziness, occur in fewer than 5% of cases and are usually mild and transient. Severe AEs, including pericardial effusion, are extremely rare and often linked to compounding errors comprising an excessive dose. Management strategies include dose reduction, pharmacological interventions like diuretics for edema, and lifestyle measures such as sodium restriction. In most cases, AEs resolve without the need for treatment discontinuation. The favorable safety profile of LDOM makes it a valuable therapeutic option for alopecia, though careful patient selection, dose titration, and monitoring are essential to minimize risks.

Efficacy and safety of low-dose oral minoxidil in the management of androgenetic alopecia

INTRODUCTION

Treating alopecia can be challenging. The available treatments are topical minoxidil, low-dose oral minoxidil (LDOM), and 5-α reductase inhibitors like finasteride and dutasteride. Only topical minoxidil and finasteride 1 mg daily are FDA-approved, while the rest are used off-label. Recent research has suggested that oral minoxidil may be a safe and effective treatment for both female androgenetic alopecia (female AGA) and male androgenetic alopecia (male AGA).

AREAS COVERED

In this review, we explore the pharmacokinetics, mechanism of action, safety, and efficacy of oral minoxidil. Additionally, we discuss its effectiveness compared to other treatments available for female AGA and male AGA.

EXPERT OPINION

LDOM has demonstrated a favorable efficacy and safety profile in several trials. Subsequently, its use for the treatment of male AGA and female AGA is increasing. However, its use remains off-label, and through increased usage, we will get a better idea of the best dosage and monitoring guidelines. LDOM has also been used with some effectiveness in other forms of hair loss.