Table 2.

Potential Drug Reactions and Interactions Between Antiretroviral Therapy and Antiobesity Medications

Medication	Maximum Dosea	Mechanism of Action	Side Effects	ART Interactions
Orlistat	120 mg TID	Pancreatic/gastric lipase inhibitor	↓ fat-soluble vitamin absorption, steatorrhea, fecal incontinence	Avoid: Loss of virologic control reported in patients taking ATV/r or EFV [S178, S179].
Phentermine/Topiramate	7.5 mg/ 46 mg QD	Norepinephrine releasing agent/ GABA receptor modulation	Insomnia, dry mouth, constipation, paraesthesia, dizziness, dysgeusia	Caution: Topiramate is a mild CYP3A4 inducer, but clinical relevance is unlikely [S180].
Lorcaserin	10 mg BID	5HT2c receptor agonist	Headache, nausea, dry mouth, dizziness, fatigue, constipation Caution if also taking: SSRI, SNRI/ MAOI, St. John’s wort, triptans, buproprion, dextromethorphan	None
Naltrexone/ Bupropion	8 mg/90 mg, 2 tabs BID	Dopamine/norepi-nephrine reuptake inhibitor/opioid antagonist	Nausea, constipation, headache, vomiting, dizziness	Caution: Bupropion CYP2B6 metabolized [S181]. EFV or RTV use may decrease concentrations. Clinical monitoring and standard bupropion doses recommended.
Liraglutide	3 mg daily	GLP-1 agonist	Nausea, vomiting, pancreatitis	None

Abbreviations: ART, antiretroviral therapy; ATV/r, ritonavir-boosted atazanavir; BID, twice daily; CYP2B6, cytochrome P450 2B6; CYP3A4, cytochrome P450 3A4; EFV, efavirenz; GABA, gamma-aminobutyric acid; GLP-1, glucagon-like peptide-1; MAOI, monoamine oxidase inhibitor; NNRTI, non-nucleoside reverse transcriptase inhibitor; PI, protease inhibitor; QD, once daily; RTV, ritonavir; SNRI, serotonin and norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TID, three times daily.

^aPlease see prescribing information for specific details including starting dose and dose titration.