It is down to cost and I would challenge it, partly because while there is clinical evidence that Cialis daily dose (2.5mg or 5mg) promotes healing of the nerve bundles and recovery of erectile function, the research found no evidence that Viagra has the same benefit. Plus Viagra 100mg every two days is an awful lot to take which means side effects are more likely.
If the GP won't bend, or it turns out that your CCG has put a ban on Cialis daily, the viagra is better than nothing If side effects are a problem, perhaps cut the tablets in half? The chemist should be able to sell you a pill-cutter.