depression pills side affect or depression symptom

hi there
i have a problem that my mum has that i want to discuss
she was suffering from major depression and for the past couple months after change of medicine she has been prescribed amitriptyline(50mg) and zolpidem(10mg)for sleeping taking 1 each every night. since she was depressed her tongue has been very sensitive and was back to normal but past a week it has become very sensitive again- when she eats food (that is mild enough for a child to eat) she finds it extremely chilly and salty as well as fizzy drinks cause the tongue to sting and hurt.
whether this is a depression symptom or reaction to medication is something i need ur help in. we have tried salty water gargles but it hasnt worked however is there any home remedy for this?
i will appreciate ur help