Maraviroc
Mechanism :
Maraviroc, a CCR5 antagonist, selectively and reversibly binds to the chemokine (C-C motif receptor 5 [CCR5]) coreceptors located on human CD4 cells. CCR5 antagonism prevents interaction between the human CCR5 coreceptor and the gp120 subunit of the viral envelope glycoprotein, thereby inhibiting gp120 conformational change required for CCR5-tropic HIV-1 fusion with the CD4 cell and subsequent cell entry.
Indication :
- Treatment of only CCR5-tropic HIV-1 infection
Contraindications :
Patients with severe renal impairment (CrCl <30 mL/minute) or end-stage renal disease (ESRD) who are taking concomitant potent CYP3A inhibitors or inducers.
Dosing :
HIV-1 infection:
Children ≥2 years and ≥10 kg and Adolescents:
Oral:
Weight <30 kg: Not recommended.
Weight ≥30 kg: 300 mg twice daily; dose recommended when maraviroc administered concomitantly with other medications that are not potent CYP3A inhibitors or inducers, including tipranavir/ritonavir,
nevirapine,
raltegravir, all NRTIs and
enfuvirtide.
Adverse Effect :
Arthritis, cough, rash, fever, dizziness, appetite disorder, herpes infection, bronchitis, sinusitis, constipation, apocrine and eccrine gland disorder, paresthesia/dysesthesia, renal/urinary disorder, depression, disturbed consciousness, peripheral neuropathies, pruritus, sensory abnormalities, folliculitis, hypertension, lipodystrophy.
Interaction :
St john's wort: Decreases the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
Carbamazepine: Decreases the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism.
Erythromycin base: Increases the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism.
Rifampin and Rifabutin: Decreases the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism.
Hepatic Dose :
Maraviroc is metabolized by the liver, hence concentrations are likely to be increased in patients with liver disease. Use with caution in patients with liver disease. Patients with moderate hepatic impairment also receiving a concomitant potent CYP3A4 inhibitor should be monitored closely for adverse events.