You should go for regular follow-up visits for HIV with your doctor, including regular HIV viral load testing, and prescription refills. Medical records documenting that you have done so, serve as evidence that you have adhered to medical treatment.

If you are alleged to have committed an offence, the strongest evidence that you have adhered to medical treatment is an undetectable HIV viral load test result (from a licenced laboratory in Singapore) at the next medical visit for HIV after the sexual activity in question (which should not be more than 9 months after the sexual activity in question). This is because maintenance of undetectable HIV viral load is not possible unless you have adhered to treatment.