To investigate the pharmacokinetic drug-drug interaction potential of fixed dose antiretroviral therapies, i.e. ATRIPLA, COMPLERA, STRIBILD, TRIUMEQ, or any approved antiretroviral protease inhibitor in combination with (preferably) TRIUMEQ, on the exposure to riociguat in HIV patients on a stable dose of one of these therapies.

• To Assess the safety and tolerability of riociguat treatment in combination with these fixed-dose antiretroviral therapies.

Inclusion Criteria:

• Male or female patients aged >=18 to <65 years with a confirmed diagnosis of HIV receiving a stable regimen of ATRIPLA, COMPLERA, STRIBILD, TRIUMEQ, or any approved antiretroviral protease inhibitor such as atazanavir, darunavir, indinavir, ritonavir, and saquinavir in combination with (preferably) TRIUMEQ consistent with the most recent prescribing information documents for at least 6 weeks before concomitant administration of a single oral dose of 0.5 mg riociguat
• No clinical evidence of pulmonary hypertension
• Written informed consent

Exclusion Criteria:

• Severe diseases for which it can be assumed that the pharmacokinetics or effects of the study drug will not be normal
• History of coronary artery disease
• Symptomatic postural hypotension (e.g. dizziness, lightheadedness)
• History of bronchial asthma or any other airway disease
• Renal impairment with creatinine clearance <15 mL/min
• Severe hepatic impairment (Child-Pugh class C)
• Systolic blood pressure below 100 mmHg