You might suggest that he discuss this with his doctor. I would bet that one of the ED drugs(Viagra, Cialis or Levitra) would probably help him to obtain an erection more readily and maintain it longer.
If premature ejaculation is an ongoing problem then Paxil can be effective to help with this. While not one its FDA indications for use, it is a well known side effect of Paxil (and other SSRI antidepressants) that it delays the time to orgasm. This can be useful in that particular situation.
I hope this information helps. If you have further questions then let me know and I will be happy to get back with you.
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Thank You and Best Regards,
Anthony Bray MD