Does oral minoxidil affect blood pressure? Small Study in Males Suggests Effects are Very Small

Does Oral Minoxidil affect Blood Pressure?

A new study examined whether oral minoxidil affects blood pressure.

Patients were assessed with ambulatory BP monitoring (ABPM), every 20 minutes for 24 hours, at 2 different days: at baseline and the day of the first intake of a 5-mg dose of minoxidil (administered at 4 PM in all patients). Mean systolic BP (mSBP), mean diastolic blood pressure (mDBP), and mean heart rate (mHR) were calculated for 2- and 4-hour intervals before and after the intake of LDOM.

A total of 20 ABPM measurements were performed in 10 otherwise healthy men, with a mean age of 27.8 years (range, 24-32).

Key Results

1) There was no statistically significant differences were found between baseline and mean 24 hr LDOM measurements in mSBP, -mDBP, and -mHR.

2) 2 hours after the 5 mg dose, there was a non significant reduction in systolic BP (from 123.6 to 121.6, p = 0.45)

3) 2 hours after the 5 mg dose, there was a significant reduction in diastolic BP (from 76.7 to 71.9, p = 0.04)

4) 2 hours after the 5 mg dose, there was a non-significant reduction in heart rate (from 78.7 to 74.5, p = 0.07)

5) There were no significant differences at the 4 hour time point

6) None of the 10 patients had tachycardia

7) Patients with high blood pressure had biggest drops in blood pressure after oral minoxidil

8) One patient had lightheadedness after LDOM administration – at the 1 hour mark. It resolved spontaneously

Conclusions

LDOM appears to have minimal affects on blood pressure. There can be slight changes in diastolic blood pressure at 2 hours but they are minor and return to normal at 4 hours.  This study did not show evidence of tachycardia. The authors did note that some of the biggest changes in blood pressure did occur in those with high blood pressure to start with suggesting that perhaps LDOM may have blood pressure lowering effects in those with high blood pressure but much more limited effects in those with normal blood pressure.

Finally the study reminds us that some patients could report lightheadedness. This may simply need monitoring and does not always require stopping the dose.

REFERENCE

Jimenez-Cauhe J 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. 2022 Dec;87(6):e235-e237. doi: 10.1016/j.jaad.2022.06.1205. Epub 2022 Aug 13.