Everyone has the right to privacy, including people who use drugs.
In accordance with this right, States should:
i. Adopt legislative, administrative, and other measures to prevent arbitrary and unlawful interference with the privacy, family life, home, and correspondence of people who use drugs.
ii. Ensure the protection of the right to privacy in relation to criminal investigations for drug-related offences.
iii. Adopt legislative and other measures to prevent the disclosure of individuals’ personal health data, including drug test results and drug dependence treatment histories, without their free and informed consent.
iv. Ensure that welfare conditionalities and administrative requirements to access rights and benefits do not unlawfully, unnecessarily, or disproportionately infringe the privacy of those who use drugs.
In addition, States may:
v. Utilise the available flexibilities in the UN drug control conventions to decriminalise the possession, purchase, or cultivation of controlled substances for personal consumption.
Here is where you will see the cited reference for the Commentary feature.