Purple Vomit from Medications: Direct Answer
None of the medications listed (baby aspirin, Lipitor, carvedilol, cinacalcet, iron, folic acid, gabapentin, hydralazine, Protonix, Requip, sevelamer, valproic acid, or Effexor) are known to cause purple-colored vomit, either individually or in combination.
Evidence-Based Analysis
Known Causes of Colored Vomit
The medical literature documents only three substances that cause distinctly colored (bluish) vomit, and none of them are present in your medication list 1:
- Copper sulfate - causes blue/bluish-green vomit
- Boric acid - causes blue vomit
- Paraquat - causes blue vomit
These are all acute poisonings rarely seen in Western emergency departments 1.
Iron Supplementation Considerations
Iron supplements can darken vomit to black or dark brown, but not purple 2. The mechanism involves:
- Iron oxidation in gastric acid producing dark hematin-like compounds
- This appears as black or tarry material, not purple coloration
- Chronic low-dose aspirin (75-100 mg daily) can cause iron deficiency anemia in 20% of elderly patients through chelating metabolites, potentially leading to gastrointestinal symptoms 2
Medication-Induced Vomiting (Without Color Change)
Several medications in your list commonly cause vomiting as an adverse effect, but without altering vomit color 3, 4:
- Valproic acid - causes gastrointestinal disturbances including vomiting 3
- Iron supplements - frequently cause nausea and vomiting 2
- Cinacalcet - commonly causes nausea and vomiting
- Hydralazine - can cause gastrointestinal upset
Critical Clinical Pitfall
Purple vomit is not a recognized medication side effect and warrants immediate investigation for other causes:
- Food dyes (red/blue combinations in foods or beverages)
- Beets or other purple foods
- Upper gastrointestinal bleeding (which appears red, brown, or black - never purple)
- Non-pharmaceutical toxic ingestions 1
Management Approach
If purple vomit is observed 1:
- Obtain detailed dietary history - specifically ask about purple/red/blue foods or beverages consumed in the past 24 hours
- Rule out toxic ingestion - specifically copper sulfate, boric acid, or paraquat if occupational or intentional exposure is possible
- Assess for gastrointestinal bleeding - though this would not appear purple
- Do not attribute the color to prescribed medications - as none cause this presentation
The absence of purple vomit as a documented side effect in extensive antiemetic and adverse drug reaction literature 5, 4, 6 strongly supports that the color originates from dietary sources rather than the medication regimen.