TL;DR: Oral minoxidil is sending my blood pressure to wavy rides and I wonder whether it is of normal occurrence. I will go see a cardiologist too, but decided to post here too.
So, I have been inactive for some time but returned back as I feel that I should ditch oral minoxidil and hop on the topical. Originally I planned to like increase dose of oral minoxidil from 2.5 to 5mg and get a baseline measurement of my BP without any oral minoxidil taken. I waited a few days (90 hours) to wait minoxidil’s BP-related effects to fully be eliminated. Oral minoxidil at 2.5mg roughly is nearly fully eliminated from the body after 48 hours, where only 0.00061035156mg of the original dose remains, ignoring any excipient/passive ingredient impacts however its BP related and antihypertensive effects last much much longer.
2.5mg*(1/2^12), 12 for half lives elapsed (1 half life=4hr, 48/4=12). After 1 half life, 1/2 of initial dose will remain for any drug, for minoxidil it is 4 hours for 1 half life.
When I do NOT take the oral minoxidil my blood pressure so to speak ranges from 10.9-12.8 for systolic and 7.9 to 8.4 for diastolic. and HB (heartbeat) is between 85-99. Sometimes heartbeat goes to low 80s. Preeeetty normal. HOWEVER, When I take 2.5mg oral minoxidil the systolic can reach upwards of 15 meanwhile diastolic can reach to 9.5, sometimes up to 9.7. Yes, 15 and 9.7, these numbers are absolutely unheard of in normotensive patients when at rest. By the way, I forgot to mention but I was at rest before, during and after taking the oral minoxidil for at least solid 40 minutes. After this happens, my systolic blood pressure drops rapidly to around 11 from 15, and diastolic from 9.7 to high 7-ish or approximately 8. a whopping 40mmhg drop for systolic and a whopping 20mmhg drop for diastolic. Immediately afterwards of systolic and diastolic drops, my heart rate goes over 100 (107 I had recorded after taking 2.5mg oral minoxidil pill) which to me seems that my heart attempts to compensate for drop in blood pressure by inducing a reflex tachycardiathat is increasing heart beat to deliver more blood in layman’s terms. Keep in mind I had no heart palpitations and my heart rate is perfectly normal. I did not develop any pericardial effusion and felt as if I had not taken oral minoxidil at all over the course of 2 months where I had taken oral minoxidil at 2.5mg every day at night.