How soon do Tamoxifen side effects start?

LL99LL

Hi everyone,

For those of you who've been on Tamoxifen, can you let me know how long it took for you to start having side effects? I started taking it 5 days ago and I've been very lucky so far to not have any problems. I'm asking because I'm going to start another medication, unrelated to breast cancer, which has some of the same side effects as Tamoxifen. The second medication was prescribed by a different dr who said it should be clear whether I'm having Tamoxifen side effects by day 4 or 5. So the dr said to add the second medication after 5 days on Tamoxifen. That seems like it might be too short of a turn around. If I do end up having side effects, I'd really like to be able to figure out which medication is causing what. (By the way, both drs have said there are no drug interactions between these two meds to worry about.)

Thanks for sharing your thoughts.

gb2115

It took a month for the hot flashes to start, a couple of months for my period cycle to change, 6 months for the dry mouth and taste changes to start, and I am now (18 months) having tendon pain that I am keeping an eye on. I disagree with your doctor saying you will know by day 5. My understanding (and experience) is that the side effects build over time.

Rah2464

I agree with gb2115. It does take a little bit. Although I had mild nausea the first two days, and vivid dreams the first week. Those subsided. Hot flashes were about a month out for me as well.

Egads007

Day 5 and my feet felt like they’d been beaten with a baseball bat when I got out of bed. By week 3 I was having horrible leg muscle spasms and gyn probs. Most of my SEs dissapeared after starting a weight bearing exercise regime. Made all the diff for me, and think it’s worth a shot. Hoping your SEs are little to none! :

KCMC

Hi, I have been on Tamoxifen for over 8 months now and I am just having muscle spasms in my legs at night, so that would be month 7. Gyn issues didn't start till after a few months, hot flashes almost immediately, vivid dreams at the beginning, nausea a few months in.

LL99LL

Wow, thanks so much to all of you for this helpful info. I didn’t realize it could take months for new side effects to start. I’ll hold off a little while longer on starting the other medication and I’ll keep in mind that if I get new side effects down the road, they may well be due to the tamoxifen. By the way, some of you mentioned having gyn issues. Can you let me know what you mean by that? I’m assuming you mean gynecological but not sure what you mean beyond that.

Thanks again

KCMC

Hi, yes gynecological issues. My "lady parts" are dry due to the lack of estrogen. I made an appointment with my gynecologist and was very frank with him. He suggested I use coconut oil to moisurize my vaginal area inside and out and have sex frequently because Tamoxifen can cause vaginal atrophy. I also came down with a nasty UTI that turned into a kidney infection, my dr thinks this was caused by the Tamoxifen and wants me to follow up with a urologist. There is a thread on here that is called I want my Mojo back. Flip through this thread and I am sure it will mention other gynecological issues, which reminds me I have terrible discharge which is suppose to be normal. I have to use panty liners all the time.

https://community.breastcancer.org/forum/150/topic...

Rah2464

Gyn issues as opposed to Gin issues. I would rather have those

Sorry feeling a little silly this morning. We just have to laugh at some of these things.

gb2115

For my GYN issues have been changes in the length of time between periods. Since 5/17 it's been roughly every 6-6.5 weeks. I hit the 7 week mark earlier this week, without the low cramping I normally get before a period, so I'm wondering when (? if) it's going to show up again. When I saw Onc in July she told me my period could still go away.

Discharge too, but not anything that can't be managed.

ata

Hello sisters with the leg cramps on Tamoxifen. I have them too but I sleep with the compression socks now and the cramps are short lasting, it is possible for me to deal with it when it happens to me. They don't wake me up with pain anymore. On the market are different types of them, in here you can see how to choose and use compression stocking.

https://www.webmd.com/dvt/choose-compression-stockings#1

ske510

Hello LL,

I started Tamoxifen a week ago (Oct 24). I had nausea during the first 3 days and fatigue. After a week those side effects have diminished for me. Today after showering I noticed a little more hair on top of drain.😲 Since our start dates are pretty close to each other I was wondering if you were having any issues with hair loss?

gb2115

Just to throw this out there, I went through a massive hair shed in the spring after starting tamoxifen---I thought it was the tamoxifen but someone on here pointed out that can be a natural result of being post-surgical. I shed for a couple of months then it went back to normal.

Ashweb901

I haven’t started tamo yet but I hear an average of a couple threemonths.

wallycat

I had my cyp2d6 checked and am an intermediate metabolizer. It took me about 6-8 months before the hell took over. I'm not sure which was worse, the tamoxifen or the arimidex but I had side effects with both of them.

For constipation (never, ever, ever had this until tamoxifen), I started taking magnesium supplements, which also helped with the leg cramps. I added Potassium supplement when the leg cramps hit all time high and frequency.