I need advice about discrimination of a mental condition at work

I'n not going to name any names but my problem is this........
An employee has been suffering from Anxiety and Panic attacks, they have had some counselling but the feeling of anxiety is still there. Forward to 6 months later... Employer tells employee they have to attend first aid course on how to administer medication to children, the employee has a known phobia of anything medical and it causes panic attacks. The employee says that she can't cope with attending the course and later is called to the office to discuss the employees "refusal" to do the course. Employee states she isn't refusing she just physically and emotionally cannot do the course. A panic attack now starts to raise its head, the employer says that the employee has had support and should now be better. (The course is not essential to job as others are able to administer the medication.) The employee is now crying but the employers shows no sympathy. I have told employee to get in touch with her union representative as I feel this is discrimination of an employee who has a mental disability. I feel there is a lack of empathy, support and understanding of what a mental disability is. Is there anything else I can advise her to do.