Maraviroc is a substrate of CYP3A4. Data indicates that it does not induce CYP3A4, or inhibit CYP3A4 and other CYP enzymes. Side effects that can be potentially porphyrinogenic are nausea and insomnia. Abdominal pain, another common side effect, can be confused with an acute porphyria attack.

Maraviroc is used in combination with other antiretroviral medicinal products, indicated for treatment-experienced adult patients infected with only CCR5-tropic HIV-1 detectable. Common side effects that can be confused with an acute porphyria attack are abdominal pain and nausea. Other common side effects are anorexia, depression and insomnia.

Maraviroc is a substrate of CYP3A4 (Abel 2008, SPC). In vitro studies have shown that CYP3A4 is the major enzyme responsible for the metabolism of maraviroc and that CYP2C9, CYP2D6 and CYP2C19 do not contribute significantly to the metabolism of maraviroc (SPC). The half-life elimination is 14-18 hours. In vitro studies have shown that maraviroc do not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 at clinically relevant concentrations (Hyland 2008, SPC). In vivo studies showed that maraviroc have no clinically relevant effect on the pharmacokinetics of midazolam, ethinylestradiol and levonorgestrel or urinary 6β-hydroxycortisol/cortisol ratio. This indicates that maraviroc has low potential to inhibit or induce CYP3A4 in vivo (Abel 2008, SPC).