Arimidex side effects kicked in on day three

I'm on my fifth day of Arimidex and haven't noticed any side effects -- yet.

How long (generally) did it take for others to notice SEs on Arimidex?

Tricia

I've been on Arimidex for over a year now.  Before starting it, I read a lot about side effects and did not like what I saw, especially about muscle and bone pain.  On this site I found a fair amount of information about the importance of having good levels of vitamin D, and my oncologist tested me, found that my levels were low and started me on vitamin D supplements.  I also began doing yoga, in addition to my regular daily exercise.  I feel quite sure that both vitamin D supplements and yoga have really helped with the side effects.  Yup, lots of hot flashes, but with the price of fuel in Vermont, it could be worse to have my own personal furnace. I would also love the nights of uninterrupted sleep that I knew in times past.  -- What I do not want is recurrence, and Arimidex has a pretty good record for prevention of recurrence.  

Triciaski, my onco said all the side effects I was likely to feel with Arimidex would be felt within the first 2 months.

Here's what the website "RxList" (http://www.rxlist.com/arimidex-drug.htm) says about the blood levels and speed of onset of the effects of Arimidex:

"Consistent with the approximately 2-day terminal elimination half-life, plasma concentrations approach steady-state levels at about 7 days of once daily dosing and steady-state levels are approximately three- to four-fold higher than levels observed after a single dose of Arimidex."  That means it takes about a week for the concentration of Arimidex to build up in your blood to where it will be during the treatment period.  That "steady-state" level is about 3 or 4 times higher than the concentration that was in the blood after taking just the first pill.

Women often wonder what would happen if they don't take the whole pill, or if they take it every-other-day instead of every day.  Here's what the RxList site says about the recommended dose:

"Mean serum concentrations of estradiol were evaluated in multiple daily dosing trials with 0.5, 1, 3, 5, and 10 mg of Arimidex in postmenopausal women with advanced breast cancer.  Clinically significant suppression of serum estradiol was seen with all doses.  Doses of 1 mg and higher resulted in suppression of mean serum concentrations of estradiol to the lower limit of detection (3.7 pmol/L)."  That means the drug was tested at a whole bunch of different concentrations.  The dose that's recommended on the label (1 mg/day) is the lowest dose that blocked estrogen (estradiol) synthesis completely.  The next-lowest dose (0.5 mg/day) suppressed it "significantly", but not as well as the 1 mg dose.  Higher doses also worked but weren't necessary, since 1 mg worked just as well as they did.

Finally, how long does it take for Arimidex to work?  RxList says:

"The recommended daily dose, Arimidex 1 mg, reduced estradiol by approximately 70% within 24 hours and by approximately 80% after 14 days of daily dosing.  Suppression of serum estradiol was maintained for up to 6 days after cessation of daily dosing with Arimidex 1 mg."  In other words, it starts working pretty quickly to inhibit estrogen (estradiol) synthesis; and the effects on estradiol synthesis last for about a week after we stop taking the drug.

The big question is, how long does it take for the lower estradiol levels to produce the typical SE's?  Some women have said it took only a few days, or even just a single pill; others have said it took a couple of weeks.

I don't think I had any SE's at all for the first 2 weeks on the drug.  I've been taking Arimidex for 8 months now, and if anything, the SE's are diminishing.  I've had the joint and muscle pain and the hot flashes etc., but it has all been just an amplification of what I've felt these past 6 years of menopause anyway.  I should note that I'm taking calcium citrate and Vitamin D3 supplements every day, and my Vitamin D levels are "great" (at the high end of the reference range).

otter

I've been on Arimidex abot 8 months now. My bones ache more than they used to - but in the same old areas where I have arthritis. I can actually predict the weather based on how my bones feel! It's not unbearable for me, so I'm not complaining really. I did notice a feeling of "racing thoughts" and general "speediness" in my mind a couple of months ago........but that could have been due to the extra cup of coffee I was drinking. Did you have your thyroid levels checked? My thyroid became underactive after I finished with surgery and chemo..........be sure your doctor doesn't overlook checking your thyroid. Five years seems soooo long to me - but the alternative (worrying about bc recurrence) is worse, so I'm going to do my best to stick it out. Good luck everyone!

I'm on my 3rd month of Arimidex my hair is thinning, I have some joint pain mostly in my legs and right thumb. I have found that Yoga basic exercising helps, gives me more energy and helps my spirtis.I take Caltrate D and have cut way back on the caffiene, Night sweats are not as bad when I wear light clothing cover with just a sheet and run the ceiling fan and a floor fan.  I just give my husband an extra blanket, I find my eyes get tired easily but a recent eye exam shows little change from my last eyeglass RX to now.  I have periods of depression, the feeling for a good cry will crop up, but I've been able to keep them at bay pretty much.  Sometimes just the usual life stressors build up. I remind myself things could be worse and for some it is. I'm glad I found this discussion group, a lot of my concerns and questions have been answered and I'm not the only one dealing with these SE.

Otter -- Thanks so much for that detailed explanation. It's been one week for me now, and just this evening I was complaining to my sister that my feet are starting to hurt. She asked what kind of hurt, and the best I can describe is as though I did a lot of walking in uncomfortable shoes. I suppose I can expect more of the same in other joints, but I'm glad to hear you think your aches and pains are diminishing. I, too, already have the gamut of menopausal symptoms, including general creakiness, so I'm still hoping the Arimidex will only make things slightly worse.

Tricia

Today is day 3 for me.  The only thing I have noticed are temperature issues.  I seem to have a 2 hour cycle. First I am cold, mostly in hands and feet, then about an hour later I am warm.  Not really a hot flash, just a warm wave--not totally unpleasant at first.  Then before I know it I am cold again.  During the day I am aware of the changes but it doesn't seem to bother me.  At night, however, I awake every 2 hours.  I wake up when I am cold. Go back to sleep. Then wake up again in 2 hours with night sweats.  It's sort of annoying.  In the past I just had night sweats about once a night.

I am 46, just post-menopausal.  My onco has me on high doses of calc, D, B-12, and folic acid supps. Hopefully that will help.

I hate sitting around waiting for SE's to happen. Makes me feel like a sitting duck!  I have heard so many stories--here and in real life--about the bone aches on Arimidex that I am nervous, but so far so good, although it may be too early to tell.

After radiation I had dry skin, dry hair, dry everything, still do, so I don't think for me that has to do with Arimidex. I think the temp changes do though.

Prior to my surgery I was a gym rat, there every day.  Since surgery, I was inactive for over a  month. Only now I am back at the gym, but lower body only, and walking.  I have the green light to go ahead with upper body next week once my compression sleeve and gauntlet arrive.  So I am hoping exercising will help too.

Katherine

Hi

I am glad someone is discussing this. Long story short I am having trouble with knee strength. I have to push myself up from chairs and I walk like an old lady, Benjamin Buttons. I do not want to take any more meds. I am trying to walk more butI have no spring in my step, I just drag along. I did not expect this and I have only been doing this for 3 mos, but have been stiff all 3. No other side effects, just old age!!!! Any advise?

wondering7

Thanks Otter for the link and for your very informative post on Arimidex. As usual you have provided a factual, easy to understand interpretation of the material.

Hi Ladies found new black box warnings and Arimidex was the second one posted.

Here is the link to all of the changed Black Box warnings the first post didn't come out to well.

http://www.fda.gov/medwatch/safety/2008/dec08.htm

I've only read two so far but was surprised to see Arimidex listed. Good luck to all of you on Arimidex, pray you can all get through the se's

I also have problems with knee strength, and several times, thought I would fall due to my knees caving in.  My sister broke her leg when she went through this a couple of years ago and it took 2 years to heal.  So please be careful!!!  Use a walker or a cane or something to give you some support.  My feet are killing me.  Seems like the bones on the top of my foot are terribly sore all the time.  Other than the bone pain, my other side affects seem bearable.   Cora

Arimedex kicked my butt for almost 2 monthes!  Hot flashes 24/7 or so it seemed!  Joint pain so bad that I started moving less!  Too many sleepless nights!  HOWEVER, after reading about all the side effects, I took some drastic action!  I talked to my husband about all my negative feelings and how in my head I knew nothing was wrong with me...needed to convince him I wasn't crazy! and that it wasn't him!... but that meds were trying to shut me down.  So, I stated religiously taking vitamin D with my muti vitamin.  Walking with friends everyday (1/2 hour -45 minutes) and with him every night even when I didn't feel like it!  I sleep with a sheet and he gets the blanket. Sometimes he gets two blankets because I need the fan! I sleep probably 5 out of 7 nights now (completely reasonable) and hot flashes are close to non existant...though I do wear sleeveless year round.  Bone pain is a phantom pain and can be worked through...I suffer from rhumatoid arthritis and I work through that the same way!  Just keep moving and you can triumph! I want 20 more years at least to see grand kids grow up... so just set a goal and stay on your meds and don't give up!

I am day 5 into Armidex but was having joint pain starting before that the ONC said was due to taxotere.  Now getting more and more sore each day.  Nothing seems to touch it and now started with hot flashes again which I thought I was done with.  I am still exercising - spinning, biking and running when I don't think my knees are going to buckle but everything is an effort.  I hope this goes away soon.  My SO wants me to see my regular doc this week and I will but I just don't want to take any more meds.  I did add Vitamin D to my regimen so will see if that helps as others have mentioned.  I hope this board keeps going as I want to see how everyone fairs on the Arimedex down the line.  Thanks for sharing.

Bobbi

Thanks Elisabeth - my Onc said I can't take Tamoxifen because of the greater risk of blood clots and I had a DVT and then lung clots about 5 years ago.  I was on blood thinner for 6 months and was told if I ever have another clot it's blood thinner for life so my onc and of course, me have been trying to avoid anything that would cause risk of a clot.  I think that's why I try to stay active.  I see our dx our very similar and that you are now on tamoxifen - good luck with that and I will check some of the other posts.

Bobbi

I had an ooph in April and switched from Tamoxifen to Arimidex in August.  Was doing just fine ... the hot flashes increased with the Rx change, but were beginning to subside again.  Ditto on the sleepless nights.  A little joint and muscle ache, but nothing to write home about.  I began taking Glucosamine and exercising more.

Unfortunately, then the carpal tunnel set in.  I didn't realize it was related to the Arimidex at first since it also coincided with a new job.  Pretty soon I was miserable ... pain and numbness in my hand all the time; lots of simple tasks were difficult; etc.  I took a holiday from Arimidex while I consulted with a hand specialist (who dx me with "classic," moderate carpal tunnel -- unlikely to resolve on its own -- and recommended I do the surgery).  Then, the symptoms started to fade.  Now, about 6 weeks into my holiday, the symptoms are completely gone.  Not the Arimidex, eh? 

New onc suggested I go back to Tamoxifen.  She reasoned that my risk of recurrence is low, so my absolute benefit from Arimidex over Tamoxifen is also low.  Therefore, I should also weigh the quality of life factors.  I started the Tamoxifen last night.  I hope this is the right decision!