What are the side effects from weening off of propranolol 160mg?

Palpitations: In your age group (26), palpitations and fast heart rate are the symptoms one would expect. In older people (>60 for women), one might occasionally see angina develop but not at your age. Slow weaning prevents all of the above - I'm referring to abrupt cessation.

Varies: This is dependent upon the problem which merited the treatment with a beta blocking drug. If one has dysautonomia, hyperthyroidism, cardiac arrhythmias or vasodepressor syncope, ones heart rate might become abnormally high, arrhythmias might return or syncope (fainting) might recur. Before tapering off a beta blocker, one should check with ones doctor to discuss it.