Generally, STDs are treated with antibiotics. If you’re prescribed antibiotics to treat an STD, it's important that you complete the course of your antibiotics, even if the symptoms go away earlier. To avoid further complications, never take or share someone else's medicine to treat your illness. Having said that, some doctors may choose to provide additional antibiotics to be given to your partner so that you can both be treated at the same time.

Reference: http://www.mayoclinic.org/diseases-conditions/sexually-transmitted-diseases-stds/diagnosis-treatment/treatment/txc-20180605/