According to European Directive 93/42/EEC, instructions for use must include information about performances and any undesirable side effects (Annex I, 13.6 [b]) and also, where appropriate, specific and useful information to avoid special risks (Annex I, 13.6 [e]).
Information you need to include
In light of the above, instructions for use must explicitly list any undesirable side effects irrespective of their rate of occurrence. The same applies to warnings and precautions that users can take to avoid possible side effects and risks.
Risks must be specified
Merely including warnings and precautions to take is not enough. Instructions for use must at least specify the risks that these measures are supposed to mitigate, given that controlling possible hazards through careful handling can never lower the probability of occurrence to zero.