What Are The Side-effects Of Isoptin?

Question: Hi I am researching the possible drug interactions and/or side-effects of the following:
Current meds -
Isoptin 240 mg x1daily (20+years). Was ceased by patient for a couple of days as BP dropped significantly to 105/44 consistently from her normal extreme of elevated BP despite medication changes to address.
Zimstat 40 mg (1/2 @ night)
Aldactane 25 mg (1/2 daily)
Dithiazide 25 mg (1/2 x twice daily)
Cartia 1

These were medications that were taken for long period but have been stopped in last 3-4 weeks:
Diabex XR 500 mg 1@ night - this has now been replaced with insulin injection XXXXXXX press 1 mg TDS - ceased 1 month ago
Lisax 20 mg - ceased 2 days ago
Nexium - ceased about 2-3 weeks ago

My elderly mother has been on this cocktail of medications for a very long time. Despite her hypertension and Diabetes is in very good health and is diligent in self care ( eats well, supplements, exercise)
In the last few months she has had some random symptoms that come and go intermittently.
The first was bowel motion changes: usually loose stool and evacuating 4-5 times first thing in morning (Chronic IBS) and sudden shift to chronic constipation ( no motion for up to 7 days. This occurred for about three weeks and was addressed with organic herbal preparations and now settled to good stool twice to three times daily. Then chest pain with severe shortness of breath and odeoma in legs and hospital admittance with diagnosis of fluid on lungs. Fluid treated and discharged and now all good.
The latest has been what she describes as throat closing and feeling as if choking. Can't swallow can't breathe, gets distresses and it worsens and breathing restricted further. She says that if she can burp it relieves it and she can breathe again and her choking subsides. This has occurred not only whilst eating, it can be when drinking and even without food or drink!
She has now had 4 diagnostic tests including Barium Swallow/Fluroscopy and Marshmallow test, an Ultrasound of throat and thyroid and Panendoscopy.
Results show all clear. The only findings were internal nodules on thyroid but Specialist did not believe this would cause choking as no protrusions evident. Symptoms ceased for about 4 weeks and now has returned.
She has been eating small meals, no irritant foods, head down and focused whilst eating and finds that very soon after eating she feels full, can't eat anywhere near as much as she used to and eats Very slowly.
She has lost considerable weight, feeling very tired and fatigued, anxious now about eating and potential consequences and so increased stress.
Could the long-term use of Nexium for her past indigestion be a reason for her experiencing a recurrence due to the suppression of HCl and stomach/pancreatic enzymes? Or maybe the long -term use of Isoptin ( rare-side-effect listed as indigestion- burping etc)?
Thanks in advance