Help for ds, who suffers with anxiety, facing apprenticeship interview

[snozzlemaid]

Ds has been suffering with anxiety for a few months and has an interview next week for an apprenticeship.
He's currently taking Sertraline and has beta blockers to take when and if required. The beta blockers don't seem to completely help when he's feeling extremely anxious.
Any one have any idea how to make them most effective? If he takes two he feels completely out of it, so probably not a good idea before an interview. If he took one every day for a few days before would the possible build up help?
He's just finished 6 sessions if CBT and is doing much better generally, but obviously an interview is really going to test him.

I think only a GP or psychiatrist can advise on the medication. However, has he tried mindfulness or simple breathing exercises to help with the anxiety? It might also help him to practise being interviewed in advance - maybe get friends / family / neighbours to role play? You could also ask him if he wants to inform them in advance that he is on this medication so they are aware of why he could be extra nervous or why he may be slightly "out of it". It depends on the employer whether that would work in his favour or against him - but it might at least make him feel less anxious if he knows they are aware of his situation.

Thanks. I don't think he'd be keen to be open as he did that where he was employed before and it all went seriously wrong. No support from manager just abuse for having one day off sick. Then made redundant very soon after. So unfortunately he's not had experience of a supportive manager.
This is for an apprenticeship with a really big company so I'd like to think they would have better HR in place to support him if he started suffering again.