ResearchSafe

Telmisartan + GLP-1, has anyone watched their blood pressure drop too far?

Posted by weekendnate in Safety & Side Effects - 1 points, 6 comments.

Been running tirzepatide for about 14 weeks now, down around 18 lbs, and during that window I added telmisartan 40 mg daily mainly for the PPAR-gamma angle and some lingering BP I wanted to control. Around week 8 I started getting lightheaded standing up, kinda foggy in the mornings, and my usual workouts felt flat.

Pulled my home readings and my systolic was sitting in the high 90s, sometimes lower first thing. Got bloodwork done and potassium came back at 5.1, still in range but higher than my baseline of 4.3. Kidneys looked fine, no big red flags.

I know GLP-1s aren't supposed to drop BP much on their own, but combined with an ARB and the weight coming off, I think the stack just overshot. I dropped telmisartan to 20 mg and the dizziness mostly cleared in a few days.

Curious if anyone else layering a GLP-1 with an ARB has watched their numbers slide more than expected, and how you handled the dose. Also worth flagging potassium if you're combining these, it creeps up quietly.

Comments

  • quiet_ironman: I tried semaglutide with losartan for about three months and felt the same wooziness in the mornings, my home cuff showed systolic in the high 80s after I stood up. Dropping the ARB to half the dose helped the dizziness fade within a week, and I added a pinch more salt to my meals to keep the pressure from falling too low. I also watched my potassium creep up a bit, so I got a repeat BMP and kept it in the normal range. Did you check your renin or aldosterone levels when you lowered the telmisar
  • weekendnate: High 80s standing is rough, glad halving the dose plus a little extra sodium worked for you. I didn't run renin or aldosterone, just a standard BMP and basic metabolic panel, but that's a fair point about the renin angle since telmisartan can push it up. I'll ask my doc if it's worth checking next round.
  • grinder265: I never had renin/aldosterone drawn honestly, just the standard BMP. Ngl my endo kinda brushed that off when i brought it up. Did you actually see a meaningful renin shift on losartan or was the BMP enough for you to feel comfortable adjusting on your own?
  • weekendnate: I never had renin or aldosterone pulled either, just the standard panel and a basic metabolic workup. My PCP was comfortable titrating based on symptoms and the BMP trend, especially since potassium was drifting up even at the lower dose. If your endo's brushing it off, I'd push for it anyway, because that ratio tells you way more about whether the ARB is actually the culprit or if something else is going on with volume status from the weight loss.
  • tracker_jade: Yeah honestly the renin/aldosterone split is probably worth checking before tweaking anything else, anecdotally my own BP runs low-ish on telmisartan and that combo would floor me. Did your doc say anything about the potassium creeping up too, or just shrug since you're still in range?
  • weekendnate: Honestly he kind of brushed past the potassium piece and said "still in range so let's just watch it." That felt lazy to me. I pushed back and asked about renin/aldosterone since you're right, that's the cleaner read. Going to push for the aldosterone test next week, and if the BP keeps drifting down on 20 mg I'm gonna ask about going every other day instead of daily.

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