Maraviroc dose should be decreased to 150 mg twice daily when co-administered with a PI other than tipranavir/ritonavir (coadministration with fosamprenavir/ritonavir is not recommended). Coadministration of lopinavir/ritonavir (400/100 mg twice daily) and maraviroc (300 mg twice daily) increased maraviroc AUC by 3.95-fold and Cmax by 1.97-fold. Lopinavir/ritonavir concentrations were not measured, but no effect is expected. In adult patients with a creatinine clearance of <80 mL/min, who are also receiving potent CYP3A4 inhibitors, the dose interval of maraviroc should be adjusted to 150 mg once daily. In addition, maraviroc should be used with caution in adult patients with severe renal impairment (CLcr <30 mL/min) who are receiving potent CYP3A4 inhibitors. An increased risk of postural hypotension may occur in patients with severe renal insufficiency who are treated with potent CYP3A inhibitors or boosted protease inhibitors (PIs) and maraviroc due to potential increases in maraviroc maximum concentrations when maraviroc is co-administered with potent CYP3A inhibitors or boosted PIs in these patients.
Celsentri Summary of Product Characteristics, ViiV Healthcare, September 2018.

The CYP3A/Pgp inhibitor lopinavir/ritonavir increased the Cmax and AUC of maraviroc. Coadministration of lopinavir/ritonavir (400/100 mg twice daily) and maraviroc (300 mg twice daily) increased maraviroc AUC, Cmax and Cmin by 3.95-fold, 1.97-fold and 9.24-fold, respectively (n=11). The recommended dose of maraviroc when coadministered with protease inhibitors (except tipranavir/ritonavir) is 150 mg twice daily. No additional maraviroc dose adjustment when coadministered with potent CYP3A inhibitors is required in patients with CrCl 30-80 mL/min. Maraviroc is contraindicated in patients with severe renal impairment (<30 mL/min) or ESRD on regular hemodialysis who are receiving potent CYP3A inhibitors.
Selzentry Prescribing Information, ViiV Healthcare, July 2018.

Coadministration increased maraviroc AUC and Cmax by 295% and 97%. The dose of maraviroc should be decreased to 150 mg twice daily during co-administration with Kaletra 400/100 mg twice daily.
Kaletra Summary of Product Characteristics, AbbVie Ltd, January 2021.

Concurrent administration of maraviroc with Kaletra will increase plasma levels of maraviroc. When coadministered, patients should receive 150 mg twice daily of maraviroc. For further details see complete prescribing information for maraviroc. Coadministration of maraviroc (300 mg twice daily) and lopinavir/ritonavir (400/100 mg twice daily) was studied in 11 subjects. Maraviroc Cmax, AUC and Cmin increased by 97%, 295% and 824%, respectively.
Kaletra Prescribing Information, AbbVie Inc, October 2020.

The effect of lopinavir/ritonavir (400/100 mg twice daily) alone or with efavirenz (600 mg once daily) on the pharmacokinetics of maraviroc (300 mg twice daily) was studied in 12 HIV- subjects. When given with lopinavir/ritonavir, maraviroc AUC was increased by 4.0-fold and Cmax by 2.0-fold. Adding efavirenz reduced the increase in maraviroc exposure by ~50% (2.5-fold increase in AUC, 1.3-fold increase in Cmax). Maraviroc dose should be decreased to 150 mg twice daily when given with lopinavir/ritonavir or lopinavir/ritonavir/efavirenz. 
A study to investigate the combined co-administration of P450 CYP3A4 inhibitors and inducers on the pharmacokinetics of the novel CCR5 inhibitor UK-427,857. Muirhead G, et al. 7th International Congress on Drug Therapy in HIV Infection, Glasgow, November 2004, abstract P284.

Coadministration of maraviroc (300 mg single dose) to HIV+ subjects stable on a lopinavir/ritonavir containing regimen (400/100 mg twice daily with 3TC/d4T, n=5) increased maraviroc AUC by 2.7-fold when compared to historical data. Maraviroc Cmax increased by 80%. 
A novel probe drug interaction study to investigate the effect of selected ARV combinations on the pharmacokinetics of a single oral dose of UK-427,857 in HIV+ subjects. Muirhead G, et al. 12th Conference on Retroviruses and Opportunistic Infections, Boston, February 2005, abstract 663.

PIs + Efavirenz 
Maraviroc dose should be decreased to 150 mg twice daily when co-administered with efavirenz in the PRESENCE of a PI (other than tipranavir/ritonavir where the dose should be 600 mg twice daily). Coadministration of efavirenz (600 mg once daily), lopinavir/ritonavir (400/100 mg twice daily) and maraviroc (300 mg twice daily) increased maraviroc AUC by 2.53-fold and Cmax by1.25-fold. Efavirenz and lopinavir/ritonavir concentrations were not measured, but no effect expected.
Celsentri Summary of Product Characteristics, Pfizer Ltd, ViiV Healthcare, September 2018.

Coadministration of lopinavir/ritonavir (400/100 mg twice daily), efavirenz (600 mg once daily) and maraviroc (300 mg twice daily) increased maraviroc AUC, Cmax and Cmin by 2.53-fold, 1.25-fold and 6.29-fold, respectively (n=11). 
Selzentry Prescribing Information, Pfizer Inc, ViiV Healthcare, July 2018.