Minoxidil-induced syncope
A 29-year-old man with no significant medical history reported to the doctors with the complaint of fainting. He reported syncope twice within the span of 3 months. Additionally, he previously experienced dizziness which felt close to fainting while getting up from his seat on the train. Moreover, throughout the 3 months, he felt lethargic while doing his daily work.
Syncope: Investigations
The doctors ran some tests to determine the cause of the syncope. However, all the reports came out normal.
History
He was an otherwise healthy individual who exercised four times a week. Moreover, he wasn’t on any other medication. Upon examination, the doctors observed that his blood pressure was significantly low for someone his age (104/62 mm Hg). The other measures including pulse and heart sounds were normal.
During the clinical assessment, he said that he takes taking Minoxidil, an over-the-counter medication used to prevent thinning of hair and baldness in males.
“Since the man had never had problems with passing out or low blood pressure before, and his symptoms began when he started using the minoxidil, it appeared to be the most likely culprit”
SAID DR. SIMON DUBREY, THE CARDIOLOGIST WHO TREATED THE MAN AT HILLINGDON HOSPITAL IN UXBRIDGE, ENGLAND, AND THE CO-AUTHOR OF THE REPORT.
Minoxidil
Minoxidil is primarily a potent vasodilator, hence used as an oral anti-hypertensive. However, doctors observed that it also increased hair thickness, so it was introduced as a topical medication to treat hair loss.
The side effect of fainting associated with the topical use of this medication in the 29-year-old alarmed the doctors. Low blood pressure and syncope can be anticipated with the oral use of the medication. However, the effect is not the same when used topically.
Eventually, the doctors concluded that the strength of topical Minoxidil he was using was 12.5% which is known as “extra-strength”. The usual concentrations available OTC are 2% and 5%. With this increased strength, the frequency of application was once per day, which caused increased absorption from the scalp in one go. Moreover, at this strength, it was able to bypass metabolism in the liver and directly affect the heart and blood vessels. Thereby, reducing blood pressure and causing syncope.
Treatment
The doctors discontinued the topical Minoxidil, after which his fainting spells ceased with no further complications.
