can antihistamines affect the level of your thyroid please.

[vickilou]

I have been taking the odd one now and again when I visit friends with cats, but just lately when I take them, in the next few days I seem to get very depressed and cant shake it off. The suns out for goodness sake and I should be happy, but no, I don't seem to able to shake this down in the dumps feeling. A chemist once told my husband that he would not give them to him, because they react with the thyroxine, and then I asked my doctor and they said that was rubbish. So I have been taking them now and again when I visit my friends, and now im miserable. Would like to know if anyone knows the answer, or if they have same problem taking antihistamines.

[RedApple Administrator]

Hi Vickilou, which sort of antihistamine are you taking? Can you tell us the chemical name, or if not, the brand name?

[RedApple Administrator in reply to RedApple]

I will add my own experience here, in case it's of help.

BT (Before Thyroid), I had never ever needed to take antihistamines. Since being on thyroid medication, I have to use them almost daily for one reason or another.

What I have found so far is:

Loratadine and Certirizine have no obvious effect on my thyroid levels, or my mental state.

I first started taking loratadine (sold under brand name Clarityn), but they seemed to 'run out' rather quickly and although they are supposed to be 'one a day', I often needed two a day (one every twelve hours) to relieve symptoms.

Certirizine (sold under brand names Zirtec and Piriteze) seems to last longer for me, and I rarely have to take more than one a day. So I most often use those now.

The other one I use is chlorphenamine. These are sold under the brand name Piriton, and are short acting, needing to be taken every 4-6 hours. These can make you drowsy, so I tend to only use these at night if possible. I do think they have some effect on mental state, and may possibly affect thyroid levels too, although I obviously have never been able to measure my thyroid hormone levels to be sure about that

Interestingly, the wiki article on chlorphenamine says this:

Although not generally approved as an antidepressant or anti-anxiety medication, chlorphenamine appears to have these properties as well.

However, it's important to be aware that people react differently to antidepressant medications, and what helps one person can actually work negatively on another. So, if this is the antihistamine that you're taking, maybe this provides a clue for you.

When I was suffering from bad insomnia, I tried the OTC product called Nytol. These are sold in the UK as sleeping aids, but are in fact 'sedating antihistamines'. (In the US, they are still sold as antihistamines, but in the UK, only as sleep aids).

These had a very,very bad effect on my mental state. I tried one a night and by the third day had sunk into a very depressed state. I will never take one of those again, ever. Did they affect my thyroid hormone levels? I have no idea. I simply know they negatively affected my mental state.

Hopefully something in there will be helpful!

[vickilou in reply to RedApple]

Hi Red Apple, the one im taking is boots own Loratadine, and trust me to be different. Ive had under active thyroid since I was 6, but only started getting allergic reactions since I was 10, when I suddenly became very allergic to horses, which was very annoying because I used to go riding every weekend. But the constant runny nose and very itchy eyes put paid to that. It wasn't till much later in life I started getting the reaction to pets too, although not all pets, I have a dog and as long as I wash my hands after making a fuss of him, I don't seem to suffer, but other peoples dogs and cats really make me suffer unless I take the Loratadine, however just recently been getting very down in the dumps a day or so after taking them. Its just typical that these affect me and not other people, as I just seem to have a knack at being akward lol. But thank you very much for the info, and perhaps if I tried another brand this might help.

[Fruitandnutcase]

Hi Vickylou

I take Loratadine every now and again with my levothyroxine and Carbimazole and I haven't noticed any problems. My husband who has no health problems takes Loratadine too - more often than I do - and they don't make him depressed or down.

Liz

Liz

[Coppernob]

Ïve taken Piriton the last two nights (for suspected interstitial cystitis). It seems to reduce the symptoms and help me sleep as well - great! But I've been tired and quite depressed the next day - Damn! Think I'll try (non-drowsy) Loratidine tonight and see if that's better.

Very interested to note that Nytol is an antihistamine as that also makes me horribly depressed. (Wonder what the mechanism is...)

[humanbean in reply to Coppernob]

There are two kinds of Nytol - a herbal kind (hops, valerian, passionflower) and the one-a-night kind which has a sedating anti-histamine as the main ingredient.

[RedApple Administrator in reply to humanbean]

The sedating antihistamine in Nytol is Diphenhydramine. As mentioned in my post further up this thread, it had a *very* bad effect on my mental state. Some people seem to be ok with it though.

[humanbean in reply to RedApple]

Yes, I use diphenhydramine occasionally and have the same problem you have. I keep my use to an absolute minimum but there are nights when desperation kicks in and I still use it.

Unfortunately for me, melatonin, which I've also tried has an even worse effect on my mental state even in minute doses.

And herbal products do nothing for me at all. As someone who has suffered from insomnia since childhood, I get very frustrated at the lack of choice there is.

[RedApple Administrator in reply to Coppernob]

The Nytol that I referred to in my post above, is the antihistamine version, not the herbal one. The active ingredient in the Nytol antihistamine version is Diphenhydramine

en.wikipedia.org/wiki/Diphe...