Hi & Welcome. I appreciate your concern for your beloved mother. Based on the history given, she seems to have developed side effects of Amlodipine alone not due to mix up with other medications. This should be brought to the notice of her treating doctor for a possible reduction in the dose or an alternate effective medication to lower her BP. Whereas when taken together a Carvedilol (alpha and beta blocker) and Amlodipine (calcium channel blocker) may have additive effects in lowering her BP & heart rate. She may experience headache, dizziness, lightheadedness, fainting, increased heart beats, palpitations, etc. However, these side effects are mostly seen at the beginning of treatment, following a dose increase, or when treatment is restarted after an interruption. If she gets those side effects as mentioned above her doctor should be consulted as she may need a dose adjustment or more frequent monitoring to safely use both medications. There is no documented interactions between Benzapril (ACE-inhibitor) and the co-prescribed medicines hence it may be continued. Hope these answer your query. Wishing your mother a very good health.