As someone who takes 17 different medicines on a daily basis. I often wonder about side effects and whether they clash. I feel GP surgeries should check patients with several ailments and their medications. Perhaps there needs to be a website such as this one where you can enter all your medications and find out the benefits (if there any) and the pitfalls of taking all your medications together. I am convinced there are many of us still taking medicine that was meant to be taken for just a short time.
Go and ask your pharmacist! I am a community pharmacist and this is what I do every day. They really won't mind if you have questions about your medicines. Do you always go to the same pharmacy? There are lots of benefits of sticking to the same place, so they have all your records and can check for safety each time you collect meds. The pharmacist can guide you through your meds and knows when to refer to the GP when appropriate. We will never tell you to stop taking anything and can't make any changes to your prescription, but are a great source of advice, and have studied pharmacy for 5 years in total, so are well placed to answer queries, supply medicines for self-care where minor ailments are concerned, and can be helpful explaining things! Good luck!
Forgot to add, re your concerns about your doctor reviewing your medicines - they do this annually as routine, or even more frequently if you are elderly or taking over a certain number. In addition, if you are on medicines requiring specific monitoring, you will be reviewed every time you request a new repeat prescription.
I would definitely not totally rely only on doctors to tell you ABSOLUTELY everything you need to know - they're only human and have so so much to do in such little time for so many. They can vary in opinion regarding some things too. It is first up to us to be alert, aware and responsible by continually taking an active part in caring for our bodies. There is a wealth of good information out there, unlike in the olden days, provided it is from the right sources and common sense is used.