Anyone Taking Midodrine & Zantac Together?

[iheartcats]

My EP is more concerned with me keeping POTS under control and taking my Midodrine for BP/Heart and Zantac for hives/allergies than the minor interaction.

I'm going to my PCP soon and was wondering what, exactly, this means and if there's a blood test I can get or something to make sure I'm not getting too much of the Midodrine? This interaction doesn't make a lot of sense to me...it's not as clear as some interactions.

ranitidine and midodrine (Minor Drug-Drug)

Theoretically, the coadministration with midodrine may result in decreased clearance of drugs that are primarily eliminated by active tubular secretion such as metformin, cimetidine, ranitidine, procainamide, flecainide, quinidine, and triamterene. The proposed mechanism is competitive inhibition of renal excretion by desglymidodrine, the active metabolite of midodrine. However, clinical data are lacking and no supportive experimental evidence exists. Patients receiving midodrine in combination with drugs that undergo active tubular secretion should be monitored for excessive effects of one or both drugs.

[Sunfish]

while it's always a good idea to pay attention to possible interactions between meds - particularly when multiple docs are involved in prescribing - i genuinely don't think you need to be worried about this one. normally i would simply tell you to not worry too much but to run it by your doctor just to make sure, ease your mind, etc. since your doc is already on board i'm going to pretty much agree with him/ her but will try to explain my rationale a bit better.

technical pharmacology jargon aside, the bottom line of the interaction warning is that taking both meds together presents the possibility that the person taking them will get "more" of one (or both). while the actual potential interaction is far more complex, the end result would be the practical equivalent of taking a higher dose of the med(s). for some meds this possibility would be something that would necessitate a lot more caution and - in some cases - might involve monitoring bloodwork. in your case, however - or perhaps more correctly in the case of the meds you're taking - you don't need to worry about anything that complex.

since "excessive effects" of any med is simply fancier lingo for more, or too much, as far as the midodrine is concerned you need only to be concerned with making sure that your blood pressure doesn't get too high....something you theoretically would/ should be doing anyway if you're on midodrine. there's no way that you could have "excessive effects" of midodrine in your bloodstream (or anywhere else in your body) which would not also act to raise your blood pressure, so in short you really don't need to worry about the midodrine side of the occasion at all b/c any concern/ monitoring would be no different than what you & your doctor would/ should already be paying attention to (in terms to how well the midodrine is working for you). per the interaction warning, there is a theoretical chance that you need a bit less midodrine since (& because) you're also taking the zantac/ ranitidine than you otherwise might; in reality this may or may not be the case.

in regard to the zantac, while it doesn't have a hallmark effect that is as obvious, quantifiable, &/or easy to measure (compared to midodrine's effect on blood pressure), it's a drug that is relatively benign in nature & effect so that the possibility that you might be getting "excessive effects" from it - what would be the equivalent of your taking a bit more than what you're technically prescribed & taking - is not anything to be concerned with. without knowing your dose i can all but guarantee that it can be prescribed in doses higher than what you're taking, and generally speaking meds used for heartburn/ reflux aren't dose-adjusted to a high degree of specificity; in other words docs will generally start with a lower dose but not hesitate to jump to twice that if & when necessary with little or no concern of prescribing a dose that's a bit of an overshoot. while all meds should obviously be used & handled properly & none should be dismissed as entirely safe or benign across the board - after all they are all meds, and not sugar pills - the reality is that some do require more diligence as well as a higher specificity when it comes to dosing. in terms of their effect on the symptoms they are intended to treat (as well as the rest of the body), the exact dose of midodrine, for instance, is somewhat more important than the exact dose of zantac; this does NOT mean that zantac is without an upper limit of safety, nor that taking more that what one needs of a med is ever a good idea, but taking a bit more zantac than needed to combat one's heartburn is not a problematic as taking too much midodrine (& thus causing hypertension). so....if you are getting a bit of "excess effect" from your zantac, there is again the chance that you're benefiting & would otherwise need a higher dose or a stronger med; but if this isn't the case & you're instead simply getting what comes down to a bit of extra zantac (relative to your symptomatic needs), it's not something you should be worried about.

while i could probably do some editing in favor of a more concise explanation, hopefully my ramblings will at least explain things well enough to put you more at ease. and help you understand the rationale/ reasoning that's behind what may have felt like lack-of-concern from your doc. let me know if you have any questions.

hope this helps,

melissa

p.s. for what it's worth i have taken both meds simultaneously myself at times in the past. the only reason i don't still is that i require something stronger than zantac to combat the degree of reflux i get with my gastroparesis.

[firewatcher]

Cat-Lady,

If I can remember, I'll ask my Dad (pharmacist.) What he told me when I started Zantac was to watch for loose stools or possibly yeast overgrowth due to the acid reduction. He warned me to take acidophilus or yogurt regularly. I know that Zantac comes in 75mg and 150mg, why not start on the lower dose first?

Drug to drug interactions are certainly something to be aware of, as are food to drug interactions (don't take ANY meds [especially ANS effective] with acidic juices like orange or grapefruit!) and also herbal to herbal/drug interactions. In looking up Turmeric and the studies, I found that many may not get any effect if it is in capsule form. It is far more active in warm liquid or oil and if you mix it with Piperine (a pepper derivative) it increases it's effectiveness by 2000% (not a typo!) Be careful!

Tiny steps, one at a time and keep a symptom log! Our systems OVER-react to everything, why should meds be any different?

[firewatcher]

OK, just talked to my Dad (Personal Doctor of Pharmacy! very handy!) and he looked it up in his books. According to what he could find, Zantac could increase the effect of Midodrine by 20%, causing supine hypotension and OI if you get up too suddenly. This has NOT been reported by any doctor or found in any studies, but could possibly happen due to chemistry and renal clearance issues.

So, along with routine BP monitoring, get up slowly and be aware of what COULD happen (but has not been reported.) Of course WE react very strangely to medication anyway, so that is routine advice for all of us.

Hope it helps.

Jennifer

[Sunfish]

jennifer -

you're definitely lucky to have your own personal pharmacist.....i can think of more than one time over the years when i could have used my own! that said, though, i'm confused by your second post & am wondering if there might be an accidental typo? what i'm wondering about is the statement you have bolded, specifically that "Zantac could increase the effect of Midodrine by 20%, causing supine hypotension and OI if you get up too suddenly." the first part, specifically that "Zantac could increase the effect of midodrine by 20%" is exactly what cat lady was asking about; the second half of the statement, however, is what i'm questioning b/c it's essentially stating that extra midodrine will have an effect OPPOSITE to what midodrine's effect generally is (rather than accentuating or increasing it's characteristic effect(s). i'm not sure if i'm being clear or making much sense, but an "increased effect of midodrine" would by its very nature have the potential of causing supine HYPERtension rather than hypotension. and since the underlying mechanism of midodrine is designed to treat orthostatic hypotension, it doesn't follow that an increased effect would have any potential of causing OI/ OH; it would be a DEcrease in the effect of midodrine that would have the potential of causing OI rather than an INcreaserather contradictory.

just trying to keep the original poster - as well as any others who might be reading now or in the future - from more confusion &/or undue concern. b/c in order to hold true to anyone's basic understanding of midodrine the bold statement either (1) has a typo or (2) begs a good deal of additional explanation (to how a - potentially - heightened effect of midodrine causes it to do the exact opposite of what it's designed for in the first place.)

thanks!

melissa

[firewatcher]

jennifer -

you're definitely lucky to have your own personal pharmacist.....i can think of more than one time over the years when i could have used my own! that said, though, i'm confused by your second post & am wondering if there might be an accidental typo? what i'm wondering about is the statement you have bolded, specifically that "Zantac could increase the effect of Midodrine by 20%, causing supine hypotension and OI if you get up too suddenly." the first part, specifically that "Zantac could increase the effect of midodrine by 20%" is exactly what cat lady was asking about; the second half of the statement, however, is what i'm questioning b/c it's essentially stating that extra midodrine will have an effect OPPOSITE to what midodrine's effect generally is (rather than accentuating or increasing it's characteristic effect(s). i'm not sure if i'm being clear or making much sense, but an "increased effect of midodrine" would by its very nature have the potential of causing supine HYPERtension rather than hypotension. and since the underlying mechanism of midodrine is designed to treat orthostatic hypotension, it doesn't follow that an increased effect would have any potential of causing OI/ OH; it would be a DEcrease in the effect of midodrine that would have the potential of causing OI rather than an INcreaserather contradictory.

just trying to keep the original poster - as well as any others who might be reading now or in the future - from more confusion &/or undue concern. b/c in order to hold true to anyone's basic understanding of midodrine the bold statement either (1) has a typo or (2) begs a good deal of additional explanation (to how a (potentially) heightened effect of midodrine causes it to do the exact opposite of what it's designed for in the first place.

thanks!

melissa

Don't know. I will confirm it with my Dad. One of us got confused. He was reading out of books they keep in the back of the pharmacy, so I will confirm which is which.

thanks!

[firewatcher]

Just a little update, my Dad (pharmacist) was very certain that the pharmacy guide he was reading from said supine HYPO-tension, not hypertension...which we both agree seems wrong if Zantac makes Midodrine MORE effective. So he is going to double check this with another reference when he gets to work on Tuesday. I'll let you know once he confirms. Good catch Melissa.

[Angelika_23]

I'm just reading this, but bear with me...

Zantac is a GERD drug, not an allergy drug. You are taking this for allergy, hives? My son takes it twice a day for his acid reflux. Did you possibly mean Zyrtec?

Sorry, I'm just confused,

Angela

[firewatcher]

I'm just reading this, but bear with me...

Zantac is a GERD drug, not an allergy drug. You are taking this for allergy, hives? My son takes it twice a day for his acid reflux. Did you possibly mean Zyrtec?

Sorry, I'm just confused,

Angela

There are 4 to 5 Histamine receptors (H1, H2, H3 and H4.) Zyrtec and "classic" anti-histamines are H1 blockers: they do not stop the release of histamine, they block it's binding to it's receptor which then blunts the inflammatory response. Zantac is an H2 histamine receptor blocker, by combining H1 and H2 blockers, you further blunt the effect of histamine. They have a few other H3 and H4 blockers but they are for far more specific uses. So Zantac is an anti-histamine as well. My allergist routinely suggests Zantac for hives.

[firewatcher]

OK, my source (my Dad is a Dr. of Pharmacy) has looked into the chemistry of both drugs and cross referenced his research with all the books in the pharmacy and here is his answer:

Zantac COULD cause an increase in the effectiveness of Midodrine due to impaired renal clearance, though it has NOT been reported clinically, it has been mentioned theoretically, which would cause supine HYPERtension, not hypotension.

In normal people speak: it means together they may cause supine hypertension but NO ONE has EVER reported it happening...yet. Again, we react differently to meds than most, so if you take them both, just monitor your reaction and make sure your doctor and pharmacist knows.

Hope this helps

[iheartcats]

OK, my source (my Dad is a Dr. of Pharmacy) has looked into the chemistry of both drugs and cross referenced his research with all the books in the pharmacy and here is his answer:

Zantac COULD cause an increase in the effectiveness of Midodrine due to impaired renal clearance, though it has NOT been reported clinically, it has been mentioned theoretically, which would cause supine HYPERtension, not hypotension.

In normal people speak: it means together they may cause supine hypertension but NO ONE has EVER reported it happening...yet. Again, we react differently to meds than most, so if you take them both, just monitor your reaction and make sure your doctor and pharmacist knows.

Hope this helps

Thank you so much for looking this up - I've been watching the page excitedly.

I take my biggest dose in the AM of Midodrine (10MG) and have been trying to remember to take my BP at least once in the AM during the first hour of taking it (since 3-4 hours after taking Midodrine I've heard it's mostly out of the system). My BP comes in at what it usually does with it...120/80 to 135/90. My EP said not to worry about spikes of anything 140/95 or lower and I've not reached that.

So the good news is it's theorteical, and I've not experienced anything out of the ordinary at least when I've taken it recently. The problem is you don't know when BP is spiking (no real symptoms, hidden issue) so I'll try to take it more the next few days.

I'm on 75MG twice a day. I may talk to my doctor about taking 150mg once at NIGHT since I only take Midodrine between 7am-5pm. If I took Zantac at night (say 8pm when I take Zyrtec) that may lessen the chance of interaction?

[firewatcher]

Thank you so much for looking this up - I've been watching the page excitedly.

I take my biggest dose in the AM of Midodrine (10MG) and have been trying to remember to take my BP at least once in the AM during the first hour of taking it (since 3-4 hours after taking Midodrine I've heard it's mostly out of the system). My BP comes in at what it usually does with it...120/80 to 135/90. My EP said not to worry about spikes of anything 140/95 or lower and I've not reached that.

So the good news is it's theorteical, and I've not experienced anything out of the ordinary at least when I've taken it recently. The problem is you don't know when BP is spiking (no real symptoms, hidden issue) so I'll try to take it more the next few days.

I'm on 75MG twice a day. I may talk to my doctor about taking 150mg once at NIGHT since I only take Midodrine between 7am-5pm. If I took Zantac at night (say 8pm when I take Zyrtec) that may lessen the chance of interaction?

Probably not since it is a renal clearance issue. It will remain in your system longer because the kidneys won't clear it as quickly as one by itself. Just watch it and check it regularly for several weeks. There ARE symptoms of high BP: headache, ringing in ears, etc. Just keep drinking so that your kidneys continue to do what they do, but you probably do that anyway. Keep us posted!

[flop]

I'm on 75MG twice a day. I may talk to my doctor about taking 150mg once at NIGHT since I only take Midodrine between 7am-5pm. If I took Zantac at night (say 8pm when I take Zyrtec) that may lessen the chance of interaction?

The interaction is that the Zantac may reach higher levels than usual in your system (because the kidneys pee it out more slowly). I would be reassured that you are on the lower dose of Zantac so a bit extra zantac in your system will still be a lot less zantac than someone taking the full dose (150mg twice daily).

For 2 years I took Midodrine and Zantac 150mg twice daily - I wasn't aware that there was a potential interaction (neither leaflet said anything) and didn't have any problems from taking both together.

If your BP isn't going too high then there is no need to worry.

Flop