It isn't a 'first-aid' kit, it's a "Emergency Medical Kit" and it contains medicines and tools that are best not touched by non-medicals. Dr's, Nurses and Paramedics are trained in the use of the contents. Flight attendants, with just six weeks training, are not.
I am surprised that Cryanair doesn't carry 'first-aid' kits with basically the same stuff as I have in my car. They must have the need for basic plasters (band-aids), gauze, tape and scissors (although the later might never make it through security).
From another forum I found this as being standard on one Network airline:
First Aid Kit:
Adhesive bandage compresses, 1-inch
Antiseptic swabs
Ammonia inhalants
Bandage compresses, 4-inch
Triangular bandage compresses, 40-inch
Arm splint, noninflatable
Leg splint, noninflatable
Roller bandage, 4-inch
Adhesive tape, 1-inch standard roll
Bandage scissors
Emergency Medical Kit:
Blood pressure cuff
Stethoscope
Tourniquet (rubber)
Air ways
Antiseptic Wipes
Epinephrine 1:1,000
Syringes
Needles
Latex gloves (pair)
Diphenhydramine for injection
Dextrose for injection
Nitroglycerin tablets
Self-inflating resuscitation device (masks)
CPR masks
IV admin. set
Alcohol sponges
Adhesive tape
Scissors
Saline solution
Analgesic
Antihistamine tablets
Atropine
Aspirin tablets
Bronchodilator
Lidocaine