Diagnosis>Organ System>

CLINICAL

• Often caused by medications: antiretrovirals (esp. RTV, other PIs, AZT), high-dose TMP-SMX, macrolides, opiates.
• Prevention or treatment of nausea important to improve adherence to therapy.
• Initiation of ART: nausea greatest in 1st 1-2 wks of ART. Consider prn antiemetic when starting some regimens.
• Nausea/vomiting may be a sign of a life-threatening reaction to ART: ABC hypersensitivity; NVP hepatotoxicity; lactic acidosis (d4T, ddI, AZT); pancreatitis w/ ddI, especially if combined with d4T (contraindicated), ribavirin (contraindicated) or TDF (reduce dose of ddI).
• Metabolic causes: adrenal insufficiency, uremia, hypercalcemia
• CNS disease: mass lesions, meningitis
• GI disease: gastritis, gastroparesis, reflux esophagitis, PUD, lymphoma, KS, hepatobiliary disease (including drug-induced hepatitis), pancreatitis
• Misc: opiate withdrawal, pregnancy

DIAGNOSIS

• Review medications and consider drug-related effects, especially life-threatening conditions (above).
• Check urine or serum HCG if pregnancy a possibility.
• Check lactic acid level if taking NRTI, esp. d4T, ddI, AZT.
• Consider measuring liver enzymes, creatinine, electrolytes, calcium, amylase/lipase.
• Consider cosyntropin stimulation test (especially with hyperkalemia, wt. loss, eosinophilia, orthostatis/hypotension).
• Consider GI and/or CNS imaging.

TREATMENT

• If pt has life-threatening ART-related side effect, stop ART.
• If Sx occurs with initiation of ART, remind pt that they may improve within 1-2 wks and consider offering symptomatic treatment.
• If Sx do not improve significantly or if symptomatic Rx inadequate, consider changing ART.
• Higher doses of RTV associated with more GI Sx than lower doses. In CASTLE study diarrhea and nausea occurred in 2% and 4% of pts taking ATV/r + TDF/FTC vs. 11% and 8% taking LPV/r twice-daily + TDF/FTC.
• NRTIs: ddI - take on empty stomach. Others - take w/ or w/o food (may be better tolerated w/ food, especially AZT).
• NNRTIs: EFV - take on empty stomach initially, to decrease CNS side effects. ETR - take w/ food. NVP - take w/ or w/o food.
• PIs: IDV - take on empty stomach. ATV, DRV/r, LPV/r solution, NFV, RTV, SQV/r, TPV/r - take w/ food. FPV, IDV/r, LPV/r tabs - take w/ or w/o food (may be better tolerated w/ food).

• Prochlorperazine (Compazine) 5-10 mg PO q6-8h prn, 25 mg PR twice-daily prn, 5-10 mg IM q3-4h prn
• Promethazine (Phenergan) 12.5-25 mg PO, PR, or IM q4-6h prn
• Trimethobenzamide (Tigan) 300 mg PO, 200 mg PR, 200 mg IM q6-8h prn
• Metoclopramide (Reglan) 10 mg PO q6h prn. For ART-associated Sx, consider 10 mg PO 30-60 min before ART.
• Ondansetron (Zofran) 8 mg PO 3 times-daily
• Dronabinol (Marinol) 2.5 mg PO twice-daily. If persistent CNS Sx, reduce to 2.5 mg/d. If tolerated, may increase to 10-20 mg/d.
• Lorazepam (Ativan) 1-3 mg PO q4-6h, max 4 mg/d
• Note: prochlorperazine, promethazine, trimethobenzamide, and metoclopramide can cause sedation and dystonic/extrapyramidal reactions.
• Ondansetron and newer 5-HT3 receptor antagonists are expensive. They are used alone or with dexamethasone for chemotherapy-induced nausea and vomiting.
• Marijuana has appetite-stimulating and antiemetic properties. Medicinal use legal only in CA and AZ.
• Lorazepam and other benzodiazepines used only for anxiety-associated nausea and vomiting, usually w/ chemotherapy.

Drug Comments

REFERENCES

REFERENCED WITHIN THIS GUIDE

• Didanosine
• Indinavir
• Lactic Acidosis
• Nutrition Care and Support
• Post-exposure prophylaxis
• Tenofovir
• Wasting