Which of the following is NOT a side effect of physiostigmine?

Physostigmine is a reversible inhibitor of acetylcholinesterase, which enhances the levels of acetylcholine at cholinergic synapses. Its action leads to a variety of side effects that reflect increased cholinergic activity in the body. The correct answer is that hypertension is not a typical side effect associated with physiostigmine.

Bradycardia, for instance, can occur as a result of increased acetylcholine activity on the heart, leading to a decrease in heart rate. Salivation is another common side effect, as stimulation of cholinergic pathways promotes secretions, including saliva. Urinary retention is typically due to enhanced bladder tone and the contraction of the detrusor muscle, which physiostigmine can also promote.

In contrast, hypertension is generally not associated with the administration of physiostigmine. Instead, the cholinergic effects promote vasodilation and a reduction in blood pressure. This makes hypertension an unlikely side effect, distinguishing it from the other symptoms mentioned.