These can include headaches, dizziness, flushing, nasal congestion, and a bit of blurred vision. Taking Cialis does not mean you are guaranteed to get an erection. For others, one can appear with greater side effects. This type is best if you do not plan to have sex regularly, but want to have the medication on hand. You will still need to be sexually stimulated to be able to get an erection and maintain it. The other part of your decision of Cialis vs Viagra will be your lifestyle. Changes to your vision are more common with Viagra, whilst Cialis more often tends to cause muscle pain.Has a generic version of Cialis been approved? Yes. The following products are equivalent to Cialis: tadalafil tablet;oral Manufacturer: ACCORD HLTHCARE . Tadalafil is in a class of drugs called phosphodiesterase-5 (PDE5) inhibitors and is available in a generic form often called generic Cialis. Tadalafil has been on the .