US regulators have given the go-ahead for once-daily low doses of Eli Lilly’s erectile dysfunction drug Cialis, which should provide a further boost to the drug’s already healthy sales.

The US Food and Drug Administration has approved Cialis (tadalafil) in once-daily oral formulations of 2.5mg and 5mg to be used by men who wish to “attempt sexual activity at anytime between doses”. Specifically, Lilly said that the new doses of the drug, which is also available in parts of Europe, “may be most appropriate for men with ED who anticipate more frequent sexual activity, eg twice weekly”.

The approval is based upon data which includes results from three Phase III studies of men with ED who took tadalafil 2.5mg and 5mg once daily “without regard to their timing of sexual activity” and experienced improved erectile function compared with those taking placebo. Cialis 5mg, 10mg and 20mg have been approved in the USA since November 2003 on an as-needed basis and provide effectiveness for 36 hours.

Lilly also noted that the wholesale price for the new doses will be comparable to Cialis for use as needed, around $350 per month. The drug in its original form has been serving the firm well and had third-quarter revenues of $311.4 million, a 27% increase. Lilly gained all of the revenues from the drug when it acquired Icos Corp last January.