Management of Vomiting in Patients Living with HIV on Antiretroviral Therapy
For patients living with HIV who experience vomiting while on antiretroviral therapy, a stepwise approach using antiemetics with preemptive prescribing is recommended to ensure medication adherence and prevent treatment interruption.
First-line Management
- Preemptive prescribing of antiemetics is recommended when initiating or modifying ARV regimens commonly associated with nausea and vomiting to improve regimen continuity and adherence 1
- Metoclopramide (10mg three times daily) is recommended as first-line therapy for ARV-associated vomiting based on the strongest available evidence 1, 2
- Dopamine antagonists such as prochlorperazine or haloperidol are effective alternatives if metoclopramide is not tolerated 1
- Ensure adequate hydration and electrolyte replacement while managing vomiting to prevent complications 1
Second-line Options
- 5-HT3 receptor antagonists (e.g., ondansetron) should be added if first-line therapy fails to control symptoms 1, 2
- For persistent vomiting, consider combination therapy with agents from different drug classes (dopamine antagonists plus 5-HT3 antagonists) 1
- Around-the-clock administration rather than PRN dosing is strongly recommended for persistent vomiting 1
Special Considerations for ARV Therapy
- Assess for potential drug-drug interactions between antiemetics and ARV medications before prescribing 1
- For patients taking dolutegravir, avoid simultaneous administration with polyvalent cations (aluminum, calcium, iron, magnesium) found in antacids as they can reduce absorption of the ARV 1
- For patients on rilpivirine, avoid proton pump inhibitors as they can reduce absorption of this ARV 1
- If vomiting persists despite antiemetic therapy, consider ARV regimen modification after consultation with an HIV specialist 3, 4
Addressing Underlying Causes
- Rule out non-ARV causes of vomiting including opportunistic infections, electrolyte abnormalities, and other medications 1
- Consider gastroparesis as a potential cause of persistent nausea and vomiting in PLHIV 3, 4
- For patients with severe vomiting affecting oral intake, alternative administration routes (such as gastrostomy tube) may be considered in extreme cases to maintain ARV therapy 5
Monitoring and Follow-up
- Monitor for extrapyramidal side effects with metoclopramide, prochlorperazine, or haloperidol, which can occur up to 48 hours after administration 2
- For patients experiencing akathisia with dopamine antagonists, administer diphenhydramine and consider switching to ondansetron, which is not associated with this side effect 2
- Assess adherence to ARV therapy regularly, as nausea and vomiting are common reasons for discontinuation of HAART 3, 4
Common Pitfalls to Avoid
- Never discontinue ARV therapy without providing adequate antiemetic support, as interruptions can lead to viral resistance 1, 6
- Avoid sedating antiemetics (like promethazine) unless sedation is specifically desired, as they may affect quality of life and daily functioning 2
- Do not overlook the possibility of anticipatory nausea and vomiting, which may require behavioral interventions in addition to antiemetics 4
- Avoid adding a single antiemetic at a time for severe vomiting; instead, use multiple concurrent agents with different mechanisms of action 1