There is no simplified way to explain it other than to say the effects of Kevzara will wear off in a few weeks after stopping the injections. Then it depends if PMR stays in remission after the injections are stopped and when Kevzara isn't in your system anymore.
Half-life is only part of it. There is also something known as being at "steady state"
"7.7 Biological Half-Life
The half-life will depend on the administered concentration. At 200 mg every 2 weeks, half-life is up to 10 days in patients with rheumatoid arthritis (RA) at steady state. At 150 mg every 2 weeks, half-life is up to 8 days in patients with RA at steady state. After the last steady state dose of 150 and 200 mg, the time to reach nondetectable concentration is 28 and 43 days, respectively." https://pubchem.ncbi.nlm.nih.gov/compound/Sarilumab
@dadcue
Steady state simply means that you are replacing with each dosage you take the same amount you are losing in between dosages. In reality the half-life basic rules are the same regardless of steady state status since half-life is a percent of a starting number and not an absolute amount. In my mind the complicating factors are more the individual variables like age, kidney and liver function, exercise, etc that are what get you to a time range for one half-life and not to a single specific amount of time for everyone. I see half-life as an estimate at best.
I just started four days ago, still on 7 mg of Prednisone. I have felt really weird and spacey since the injection and also experiencing PMR pain in gluts and legs plus skin is itching more than normal. Anybody else experienced any problems when starting Kevzara?
@dadcue
Steady state simply means that you are replacing with each dosage you take the same amount you are losing in between dosages. In reality the half-life basic rules are the same regardless of steady state status since half-life is a percent of a starting number and not an absolute amount. In my mind the complicating factors are more the individual variables like age, kidney and liver function, exercise, etc that are what get you to a time range for one half-life and not to a single specific amount of time for everyone. I see half-life as an estimate at best.
I only know what happened when my Actemra injections were stopped during Covid when supplies were limited to seriously ill Covid patients. It took a few weeks for my symptoms to return. My symptoms returned gradually and eventually I needed to take Prednisone again. It was NOT like a sudden full-on relapse that could happen overnight when I was on prednisone for 12 years.
I was off Actemra for a total of 6 months and needed 15 mg of Prednisone again. What was impressive was what happened when Actemra injections were restarted. I was able to taper off prednisone again quickly. I went from 15 mg to zero again in about 3 weeks after the injections were restarted.
--------------------------------
Another time I was switched to a monthly Actemra infusion to facilitate the surgical fusion of my lumbar spine. The surgeon said I had to be off Actemra for one month before surgery and one month after surgery. I didn't think I could do that when I needed weekly Actemra injections. Since Actemra infusions were every 4 weeks I only had to be able to skip one infusion. I probably could have done that. My inflammation markers started to increase at 7 weeks after my last Actemra infusion but I didn't have any pain.
What was remarkable was that my need for a lumbar fusion was because a synovial cyst formed on my lumbar spine. While I was doing Actemra infusions the synovial cyst was reabsorbed and I no longer needed surgery. The surgeon said that sometimes happens. AI says the "spontaneous resorption" of a lumbar synovial cyst is rare.
"Spontaneous resolution of lumbar synovial cysts is considered an extremely rare event, with only a limited number of cases documented in medical literature. While most symptomatic cases require surgical excision, these cysts can occasionally disappear on their own, often linked to spontaneous rupture, decreased inflammation, or stabilization of the spine."
---------------------
My rheumatologist thought decreased inflammation while I was doing Actemra infusions was the most likely explanation. In any case, the synovial cyst hasn't recurred. My rheumatologist wanted me to stay on Actemra infusions. I was glad because I was getting tired of doing weekly injections.
@dadcue
Steady state simply means that you are replacing with each dosage you take the same amount you are losing in between dosages. In reality the half-life basic rules are the same regardless of steady state status since half-life is a percent of a starting number and not an absolute amount. In my mind the complicating factors are more the individual variables like age, kidney and liver function, exercise, etc that are what get you to a time range for one half-life and not to a single specific amount of time for everyone. I see half-life as an estimate at best.
@jabrown0407
Ok, so let me seee…..
8 wks past last injection of 200mg at a 3 week interval……means I have nothing in my system?
Are we suggesting that because my CRP is elevated, and no Kevzara in my system…I need to restart as a precaution?
Restart at 3 wk intervals which I was in for 4 months before stopping?
Reminder, fully active at 80 yo, and no inflammation symptoms except a chronic knee. Still hike, bike, walk when I golf, comfortably handle a 4.5 mile walk at 19 min mile with elevation chg.
Thxxxxx everyone
I only know what happened when my Actemra injections were stopped during Covid when supplies were limited to seriously ill Covid patients. It took a few weeks for my symptoms to return. My symptoms returned gradually and eventually I needed to take Prednisone again. It was NOT like a sudden full-on relapse that could happen overnight when I was on prednisone for 12 years.
I was off Actemra for a total of 6 months and needed 15 mg of Prednisone again. What was impressive was what happened when Actemra injections were restarted. I was able to taper off prednisone again quickly. I went from 15 mg to zero again in about 3 weeks after the injections were restarted.
--------------------------------
Another time I was switched to a monthly Actemra infusion to facilitate the surgical fusion of my lumbar spine. The surgeon said I had to be off Actemra for one month before surgery and one month after surgery. I didn't think I could do that when I needed weekly Actemra injections. Since Actemra infusions were every 4 weeks I only had to be able to skip one infusion. I probably could have done that. My inflammation markers started to increase at 7 weeks after my last Actemra infusion but I didn't have any pain.
What was remarkable was that my need for a lumbar fusion was because a synovial cyst formed on my lumbar spine. While I was doing Actemra infusions the synovial cyst was reabsorbed and I no longer needed surgery. The surgeon said that sometimes happens. AI says the "spontaneous resorption" of a lumbar synovial cyst is rare.
"Spontaneous resolution of lumbar synovial cysts is considered an extremely rare event, with only a limited number of cases documented in medical literature. While most symptomatic cases require surgical excision, these cysts can occasionally disappear on their own, often linked to spontaneous rupture, decreased inflammation, or stabilization of the spine."
---------------------
My rheumatologist thought decreased inflammation while I was doing Actemra infusions was the most likely explanation. In any case, the synovial cyst hasn't recurred. My rheumatologist wanted me to stay on Actemra infusions. I was glad because I was getting tired of doing weekly injections.
@dadcue As for rare, I have nothing less than a dozen rare medical conditions, including being allergic to all NSAIDs as well as being allergic to Tylenol. If I ever become allergic to wine it's all over.
What I realize is biologics are not as simple to calculate half lives, and any calculated value based on research is only an estimate, not a fact I would bet on. Half lives of antibiotics are easier to understand and calculate. Not sure what the difference is and really don't care. Looking for medical-life balance in my golden years and it's elusive. I did not retire to have medical problems consume my work hours.
@dadcue As for rare, I have nothing less than a dozen rare medical conditions, including being allergic to all NSAIDs as well as being allergic to Tylenol. If I ever become allergic to wine it's all over.
What I realize is biologics are not as simple to calculate half lives, and any calculated value based on research is only an estimate, not a fact I would bet on. Half lives of antibiotics are easier to understand and calculate. Not sure what the difference is and really don't care. Looking for medical-life balance in my golden years and it's elusive. I did not retire to have medical problems consume my work hours.
I don't have any allergies ... thank God for that because I have more than enough to worry about. I'm also glad I no longer have to decide how much Prednisone to take every day.
My rheumatologist decides my Actemra dose and the infusion center gives me a choice within a week or two either way for when I take it. I have done 3 weeks between infusions but not more than 7 weeks but usually every 4 weeks.
The infusion center nurse says my rheumatologist wants me to have 50 mg of Benadryl and 650 mg of Tylenol a half hour before every infusion to decrease the chance for a reaction so I take that too. 👍
@jabrown0407
Ok, so let me seee…..
8 wks past last injection of 200mg at a 3 week interval……means I have nothing in my system?
Are we suggesting that because my CRP is elevated, and no Kevzara in my system…I need to restart as a precaution?
Restart at 3 wk intervals which I was in for 4 months before stopping?
Reminder, fully active at 80 yo, and no inflammation symptoms except a chronic knee. Still hike, bike, walk when I golf, comfortably handle a 4.5 mile walk at 19 min mile with elevation chg.
Thxxxxx everyone
@tweetypie13 No, I am suggesting five half life's equals whatever. I don't know what that calculates out to be. I am not willing to support your 8 weeks data. You maybe accurate, I simply can not commit. I am not medically trained and I am not an authority.
@tweetypie13 No, I am suggesting five half life's equals whatever. I don't know what that calculates out to be. I am not willing to support your 8 weeks data. You maybe accurate, I simply can not commit. I am not medically trained and I am not an authority.
@stonewheel
Started Kevzara March 2025 @ abt 8 mg prednisone.
Off all prednisone by 7/15/2025
11/5/2025 chged Kevzara to every 3 weeks because of low WBC.
Jan 2026, blood work normal, stayed at Kevzara 3 week intervals.
Last Kevzara shot 2/22/2026…….stopped cold and no side effects.
Note: I was not, and am not, on any other medications for any other conditions .
I am now 2 months since last shot, blood work shows elevated CRP (10.8). I am not feeling it, 🤞, Dr wants me to restart Kevzara, I’m asking to retest in another 2 months. Wait and see, if a problem reach out to him. Note, I have not heard back yet. 🤞
I only know what happened when my Actemra injections were stopped during Covid when supplies were limited to seriously ill Covid patients. It took a few weeks for my symptoms to return. My symptoms returned gradually and eventually I needed to take Prednisone again. It was NOT like a sudden full-on relapse that could happen overnight when I was on prednisone for 12 years.
I was off Actemra for a total of 6 months and needed 15 mg of Prednisone again. What was impressive was what happened when Actemra injections were restarted. I was able to taper off prednisone again quickly. I went from 15 mg to zero again in about 3 weeks after the injections were restarted.
--------------------------------
Another time I was switched to a monthly Actemra infusion to facilitate the surgical fusion of my lumbar spine. The surgeon said I had to be off Actemra for one month before surgery and one month after surgery. I didn't think I could do that when I needed weekly Actemra injections. Since Actemra infusions were every 4 weeks I only had to be able to skip one infusion. I probably could have done that. My inflammation markers started to increase at 7 weeks after my last Actemra infusion but I didn't have any pain.
What was remarkable was that my need for a lumbar fusion was because a synovial cyst formed on my lumbar spine. While I was doing Actemra infusions the synovial cyst was reabsorbed and I no longer needed surgery. The surgeon said that sometimes happens. AI says the "spontaneous resorption" of a lumbar synovial cyst is rare.
"Spontaneous resolution of lumbar synovial cysts is considered an extremely rare event, with only a limited number of cases documented in medical literature. While most symptomatic cases require surgical excision, these cysts can occasionally disappear on their own, often linked to spontaneous rupture, decreased inflammation, or stabilization of the spine."
---------------------
My rheumatologist thought decreased inflammation while I was doing Actemra infusions was the most likely explanation. In any case, the synovial cyst hasn't recurred. My rheumatologist wanted me to stay on Actemra infusions. I was glad because I was getting tired of doing weekly injections.
@dadcue I was on Actemra infusions for 5 years. It was a game changer for me. I was able to work as a Physican Assistant in a fast paced urgent care doing 12+ hour shifts.
I got C-Diff and had a bowel rupture which caused a catastrophic illness. 4 month hospital stay. It was after all of this that I paid attention to one of the side effects of Actemra is bowel rupture which rare. I was not able to resume the Actemra due to that side effect. Hence the Kevzara. If I had to do all over again I’m not so sure I still wouldn’t have used Actemra because it improved my quality of life three fold.
Pray it continues to help you, Lord knows I miss it making me better for the five years it did.
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@dadcue
Steady state simply means that you are replacing with each dosage you take the same amount you are losing in between dosages. In reality the half-life basic rules are the same regardless of steady state status since half-life is a percent of a starting number and not an absolute amount. In my mind the complicating factors are more the individual variables like age, kidney and liver function, exercise, etc that are what get you to a time range for one half-life and not to a single specific amount of time for everyone. I see half-life as an estimate at best.
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1 ReactionI just started four days ago, still on 7 mg of Prednisone. I have felt really weird and spacey since the injection and also experiencing PMR pain in gluts and legs plus skin is itching more than normal. Anybody else experienced any problems when starting Kevzara?
@jabrown0407
I only know what happened when my Actemra injections were stopped during Covid when supplies were limited to seriously ill Covid patients. It took a few weeks for my symptoms to return. My symptoms returned gradually and eventually I needed to take Prednisone again. It was NOT like a sudden full-on relapse that could happen overnight when I was on prednisone for 12 years.
I was off Actemra for a total of 6 months and needed 15 mg of Prednisone again. What was impressive was what happened when Actemra injections were restarted. I was able to taper off prednisone again quickly. I went from 15 mg to zero again in about 3 weeks after the injections were restarted.
--------------------------------
Another time I was switched to a monthly Actemra infusion to facilitate the surgical fusion of my lumbar spine. The surgeon said I had to be off Actemra for one month before surgery and one month after surgery. I didn't think I could do that when I needed weekly Actemra injections. Since Actemra infusions were every 4 weeks I only had to be able to skip one infusion. I probably could have done that. My inflammation markers started to increase at 7 weeks after my last Actemra infusion but I didn't have any pain.
What was remarkable was that my need for a lumbar fusion was because a synovial cyst formed on my lumbar spine. While I was doing Actemra infusions the synovial cyst was reabsorbed and I no longer needed surgery. The surgeon said that sometimes happens. AI says the "spontaneous resorption" of a lumbar synovial cyst is rare.
"Spontaneous resolution of lumbar synovial cysts is considered an extremely rare event, with only a limited number of cases documented in medical literature. While most symptomatic cases require surgical excision, these cysts can occasionally disappear on their own, often linked to spontaneous rupture, decreased inflammation, or stabilization of the spine."
---------------------
My rheumatologist thought decreased inflammation while I was doing Actemra infusions was the most likely explanation. In any case, the synovial cyst hasn't recurred. My rheumatologist wanted me to stay on Actemra infusions. I was glad because I was getting tired of doing weekly injections.
@jabrown0407
Ok, so let me seee…..
8 wks past last injection of 200mg at a 3 week interval……means I have nothing in my system?
Are we suggesting that because my CRP is elevated, and no Kevzara in my system…I need to restart as a precaution?
Restart at 3 wk intervals which I was in for 4 months before stopping?
Reminder, fully active at 80 yo, and no inflammation symptoms except a chronic knee. Still hike, bike, walk when I golf, comfortably handle a 4.5 mile walk at 19 min mile with elevation chg.
Thxxxxx everyone
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Helpful -
Hug
1 Reaction@dadcue As for rare, I have nothing less than a dozen rare medical conditions, including being allergic to all NSAIDs as well as being allergic to Tylenol. If I ever become allergic to wine it's all over.
What I realize is biologics are not as simple to calculate half lives, and any calculated value based on research is only an estimate, not a fact I would bet on. Half lives of antibiotics are easier to understand and calculate. Not sure what the difference is and really don't care. Looking for medical-life balance in my golden years and it's elusive. I did not retire to have medical problems consume my work hours.
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Like -
Helpful -
Hug
2 Reactions@jabrown0407
I don't have any allergies ... thank God for that because I have more than enough to worry about. I'm also glad I no longer have to decide how much Prednisone to take every day.
My rheumatologist decides my Actemra dose and the infusion center gives me a choice within a week or two either way for when I take it. I have done 3 weeks between infusions but not more than 7 weeks but usually every 4 weeks.
The infusion center nurse says my rheumatologist wants me to have 50 mg of Benadryl and 650 mg of Tylenol a half hour before every infusion to decrease the chance for a reaction so I take that too. 👍
-
Like -
Helpful -
Hug
1 Reaction@tweetypie13 No, I am suggesting five half life's equals whatever. I don't know what that calculates out to be. I am not willing to support your 8 weeks data. You maybe accurate, I simply can not commit. I am not medically trained and I am not an authority.
@jabrown0407 I am grateful for any crumb that gets me asking the right questions for the Dr.
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1 Reaction@tweetypie13
Thank you for sharing. I knew you had stopped Krvzara but wasn’t sure how.
My wish for you is that your pain doesn’t return so you can continue to temain off Kevzara.
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1 Reaction@dadcue I was on Actemra infusions for 5 years. It was a game changer for me. I was able to work as a Physican Assistant in a fast paced urgent care doing 12+ hour shifts.
I got C-Diff and had a bowel rupture which caused a catastrophic illness. 4 month hospital stay. It was after all of this that I paid attention to one of the side effects of Actemra is bowel rupture which rare. I was not able to resume the Actemra due to that side effect. Hence the Kevzara. If I had to do all over again I’m not so sure I still wouldn’t have used Actemra because it improved my quality of life three fold.
Pray it continues to help you, Lord knows I miss it making me better for the five years it did.