No, you've missed the point again. In the US it available at 10mg in a single dose. Their FDA is fine with that. The OP is in the US. Therefore sending them back to their GP who follows FDA guidance, not BNF, is a bit pointless for the OP. The issues of who is right is a fight between the FDA and the BNF. A question might be what dose do the US use but I would also question why they allow general sale if a prescribed dose is lower. If the OP was in the UK I would agree with you.