Pregabalin with cetirizine or loratidine

Hi to everyone.

I’ve been on pregabalin for my anxiety and pain for a good 9 months and it’s a great drug, had no issues with side effects at all until recently. I’ve started on antihistamines for hayfever with summer approaching and they seem to be reacting with pregabalin. I’m getting extremely lethargic, dizzy, and horrible fatigue attacks where I just have to go to sleep. I have health anxiety and was convincing myself I’m getting chronic fatigue syndrome but then my partner thought about the antihistamines.

So my questions is has anyone experienced this themselves? Is there an actual interaction as I can’t realky find anything online and I am hoping it is an interaction and I’m not just getting sudden side effects to pregab itself out of the blue as it’s been an amazing drug for me.

According to the interactions checker on Drugs.com there is no known interaction between Preg and Loratidine.

However, there is a Moderate interaction warning between Preg and Cetirizine:

Using cetirizine together with pregabalin may increase side effects such as dizziness, drowsiness, and difficulty concentrating. Some people, especially the elderly, may also experience impairment in thinking, judgment, and motor coordination. You should avoid or limit the use of alcohol while being treated with these medications. Also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medications affect you. Talk to your doctor if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

You could talk to the pharmacist who can advise on this but I would be putting my money on that being the cause if it's come out of nowhere, happened near to starting them and there is nothing going on in your life to ramp up any anxiety.

Cetirizine is a drowsy one anyway so I always avoid that and go with Loratidine.