The 24-year-old was arrested at 3am on Saturday in Weybridge following Harlequins' 21-10 Heineken Cup defeat by Toulouse.
The England scrum-half was released without charge and he paid a fixed penalty fine.
The Rugby Football Union have taken no disciplinary action but Care has accepted a fine from Harlequins for breaking the club's code of conduct.
Care's fine will be donated to the Teenage Cancer Trust unit at University College Hospital in London.
Harlequins director of rugby Conor O'Shea said: "We have a crucial Heineken Cup match at the weekend in Toulouse, so it was important we acted quickly.
"We take it very seriously. However, from the club's point of view a line will be drawn under the incident and we will get on with our preparation for the match.
"Danny has apologised to his team and understands fully what is expected of him."
Care was reprimanded by England's interim head coach Stuart Lancaster, who he has known since his days in the Leeds academy, but no formal action was taken by the RFU.
"It was a silly thing to do - I accept that and apologise completely," Care said.
"We had just played a tough game and I was out with some of the team and friends but should have remembered that, as a professional player, I am on duty throughout the season and need to set a better example to the fans.
"I totally accept the police and club fines."