Third study of Oral Minoxidil in Pediatric Patients: A study of 192 Adolescents

Good safety of Oral Minoxidil in 192 Adolescents.

Authors from Australia set out to retrospectively reviewed the records of all patients aged between 13 and 18 years old who were seen at their clinic over a 20 year period and treated with LDOM or sublingual minoxidil (SLM) for a minimum of 3 months. Data on the patients’ minimum and maximum dosages, treatment formulation, duration, concurrent medication, reported outcomes adverse effects were documented.

192 patients  were included in the review  - including 80 male patients and 112 female patients.  101 had a diagnosis of androgenetic alopecia (AGA) and 91 had a diagnosis of alopecia areata (AA) or alopecia totalis (AT).

160 received oral minoxidil; 32 received sublingual minoxidil

The mean age at presentation was 16 years 3 months. Unfortunately we do not know the age range or distribution of ages. 37 patients received systemic minoxidil monotherapy and 32 were prescribed SLM.

The decision on oral minoxidil vs sublingual was selected based on patient preference, physician recommendation and price. SLM is being studied by Dr Sinclair and others. It should be noted that SLM has greater bioavailability than LDOM at similar doses and bypasses hepatic metabolism.

Many patients used other medications too. Concurrent systemic medications included a range of treatments for alopecia areata such as prednisolone, methotrexate, azathioprine, baricitinib, tofacitinib, ciclosporin and a range for treatments for AGA such as spironolactone, finasteride,  bicalutamide, flutamide and cyproterone.

The mean treatment duration was 20.12 months (range=3-87 months).

The mean starting dose of LDOM or SLM was 0.43 mg/day (range=0.1-1mg/day). In all cases, the minoxidil dose was increased at subsequent visits of between 2-3 monthly intervals but not reduced. The mean final  dose was 0.99mg/day (range=0.15-5mg/day). Most adolescent patients in this study received 0.5 mg or 1 mg.

Adverse effects were reported in 65 patients. That works out to around 34 %. (LDOM=56 or 35 %, SLM=9 or 28 %). The most frequently reported treatment related adverse events were hypertrichosis (n=22 or 11.4 % ), postural hypotension (n=16 or 8.3 %), nausea (n=6 or 3.1 %), headaches (n=6 or 3.1 %), and palpitations/tachycardia (n=5 or 2.6 %). In these cases, symptoms were mild and did not lead to discontinuation of therapy or dose adjustment. There were no serious adverse events and no notable differences in adverse event frequency or type between LDOM and SLM.

 

Comment and Discussion

 This is an interesting study. The authors concluded that LDOM or SLM in adolescents has an acceptable safety and tolerability profile. Hypertrichosis was the most commonly observed adverse event in 11 %. Headaches and nausea occur in some adolescents as does postural hypotension. It’s not clear how often shedding occurs but in other studies it was an issue in 4 % of children.

Below are the side effects reported in the three studies of oral minoxidil in children to date. Jergen et al was a study of 8 patients age 2-10 using oral minoxidil for loose anagen syndrome. Nicolas-Ruanes et al was a study of 45 patients age 10 to 17 using oral minoxidil for androgenetic hair loss or telogen effluvium. The current study by John et al, was a study of 192 patients age 13-18 using oral or sublingual minoxidil for androgenetic alopecia or alopecia areata.

It's not clear how best to dose teenagers. The authors started 0.1 to 1 mg but it would have been helpful to have more insight into dosing. I start 0.25 mg in teenagers age 10-14 years and 0.5 mg in patients 14-17 years and then increase from there.  That starting dose keeps us at around 0.01 mg per kg. Generally we increase faster in males than females and many adolescent males 16-18 years are using 1 mg to 2 mg.

REFERENCE

John JM et al. Safety and tolerability of low-dose oral minoxidil in adolescents: A retrospective review. J Am Acad Dermatol . 2022 Jul 5;S0190-9622(22)02245-9.

Nicolas-Ruanes et al. Low-dose oral minoxidil for treatment of androgenetic alopecia and telogen effluvium in a pediatric population: A descriptive study. J Am Acad Dermatol . 2022 Apr 26;S0190-9622(22)00696-X.

Jerjen R et al. Low-dose oral minoxidil improves global hair density and length in children with loose anagen hair syndrome. Br J Dermatol. 2021;184(5):977-978.