In patients with a history of postural hypotension who are receiving low-dose oral minoxidil (LDOM) for androgenetic alopecia, the use of ambulatory blood pressure monitoring before the initial dose might be worth observing. A before-after study was conducted in patients with androgenetic alopecia who were eligible for LDOM treatment in real clinical practice. Results of the analysis were published recently in the Journal of the American Academy of Dermatology.
The researchers sought to evaluate the variation in blood pressure (BP) and heart rate (HR) following the initial intake LDOM. All participants underwent ambulatory blood pressure monitoring every 20 minutes for 24 hours on 2 different days: at baseline and on the day of the first intake of minoxidil 5 mg, which was administered at 4:00 PM in all participants. Since the hypotensive effect of minoxidil becomes maximum at 2 hours and the plasma half-life of the agent is 4 hours, mean systolic BP (mSBP), mean diastolic BP (mdBP), and mean HR (mHR) were measured at 2-hour and 4-hour intervals before and following the intake of LDOM.
Among a group of 10 otherwise healthy men, a total of 20 APBM measurements were performed. The mean age of the men was 27.8 years (range, 24 to 32 years).
Results of the study showed that no statistically significant differences were observed between the baseline and LDOM measurements in 24-hour mSBP, mDBP, and mHR. Between 2 hours and 4 hours before and after LDOM intake, however, a nonsignificant reduction in both mSBP and mDBP was reported, when compared with the same intervals at baseline. The reduction was higher in the initial 2 hours following LDOM intake, then began to normalize after 4 hours.
Participants with high SBP (ie, >130 mm Hg) in the 2 hours before LDOM administration experienced a significantly higher reduction in the 2 hours following intake, compared with patients with normal SBP (-11.7 mm Hg vs -4.8 mm Hg, respectively; P =.14).
A participant reported lightheadedness at 1 hour after taking LDOM, with a reduction in his BP observed. It resolved spontaneously with no additional clinical relevance. Tachycardia was not reported in any of the participants.
The researchers noted that those participants with high SBP demonstrated a higher reduction in SBP than did those with normal SBP; this is consistent with theories that LDOM has minimal or no hypotensive effect in normotensive patients.
The investigators concluded that the “administration of minoxidil 5 mg in normotensive patients produced a slight reduction in blood pressure, in line with previous studies.” The reduction was higher in the initial 2 hours after LDOM intake and in those individuals with high BP. The use of ambulatory blood pressure monitoring before an initial dose of LDOM “could be interesting in patients with [a] personal history of postural hypotension.”
Jimenez-Cauhe J, Saceda-Corralo D, Hermosa-Gelbard A, et al. Before-after study with 24-hour ambulatory blood pressure monitoring after the first dose of 5 mg oral minoxidil. J Am Acad Dermatol. Published online August 13, 2022. doi:10.1016/j.jaad.2022.06.1205