What are the next steps in managing a post-Lower Segment Caesarean Section (LSCS) patient diagnosed with Plasmodium vivax malaria who has completed 3 days of IV artesunate (inj flacigo) treatment?

Management of Post-LSCS Patient with P. vivax Malaria After 3 Days of IV Artesunate

After completing 3 days of IV artesunate for P. vivax malaria, immediately transition to oral chloroquine (if chloroquine-sensitive region) or an artemisinin-based combination therapy (ACT) to complete blood-stage treatment, followed by primaquine 15-30 mg daily for 14 days to prevent relapse—but only after confirming G6PD status. 1, 2

Immediate Next Steps

1. Complete Blood Schizontocidal Treatment

• Switch to oral therapy once the patient is clinically improved and able to take oral medications 1
• Chloroquine remains the treatment of choice for P. vivax in chloroquine-sensitive areas: 600 mg base, then 600 mg at 24 hours, then 300 mg at 48 hours (total 1,500 mg over 3 days) 1
• Alternative option: Complete a full course of an ACT if chloroquine resistance is suspected or confirmed in your region 1, 3
• Artesunate alone provides excellent blood schizontocidal effect but must be followed by additional therapy 4

2. Mandatory G6PD Testing Before Primaquine

• G6PD testing is absolutely mandatory before administering primaquine to prevent life-threatening hemolysis 1, 2
• This is particularly critical in Asian populations where severe G6PD deficiency is more common 1
• Do not delay G6PD testing—this is a critical safety step that cannot be omitted 2

3. Primaquine for Radical Cure (Hypnozoite Eradication)

For G6PD-normal patients:

• Standard dose: 15 mg base daily for 14 days 1, 2, 5
• High-standard dose: 30 mg base daily for 14 days (0.5 mg/kg/day) is increasingly recommended and provides 80% risk reduction of relapse 1, 2
• Primaquine should be started concurrently with or immediately after blood schizontocidal treatment 2, 5
• Co-administration with chloroquine enhances primaquine efficacy by boosting blood levels 1, 2

For patients with mild-moderate G6PD deficiency (30-70% activity):

• Modified regimen: 45 mg base once weekly for 8 weeks 1, 2
• This reduces hemolysis risk while maintaining anti-hypnozoite efficacy 2

Absolute contraindications to primaquine:

• Pregnancy (this patient is post-LSCS, so defer primaquine if breastfeeding) 1, 2
• Severe G6PD deficiency 1, 2
• Infants less than 6 months 2

4. Monitoring Requirements

Parasitemia monitoring:

• Check blood smear on day 3 (expect 75% reduction from baseline) and day 7 (expect negative result) 1
• If parasitemia persists or increases, consider treatment failure or resistance 1

Post-artesunate delayed hemolysis (PADH) monitoring:

• Monitor hemoglobin, haptoglobin, and lactate dehydrogenase at days 7,14,21, and 28 1
• This complication can occur even after successful parasite clearance 1

Primaquine-related hemolysis monitoring:

• Watch for dark urine, jaundice, fatigue, particularly in the first week 2
• In G6PD-deficient patients on modified regimens, monitor closely for hemolysis 1, 2

Critical Pitfalls to Avoid

1. Never omit primaquine in P. vivax malaria

• Without primaquine, 50% of patients will experience relapse from dormant liver hypnozoites 1, 6
• Relapse typically occurs within 3 weeks if primaquine is inadequate or omitted 4

2. Never give primaquine without G6PD testing

• Administration without knowing G6PD status risks severe hemolytic anemia 1, 2
• In one study, 31% of G6PD-deficient patients required primaquine discontinuation due to significant hematocrit decrease 6

3. Never use artesunate monotherapy

• Artesunate alone (without follow-up treatment) leads to treatment failure and promotes resistance 4
• Always complete with full course of chloroquine or ACT 1

4. Special consideration for breastfeeding post-LSCS patients

• Primaquine is contraindicated during breastfeeding 2
• If breastfeeding, defer primaquine until after weaning, or test infant's G6PD status and counsel on risks
• Chloroquine is safe during breastfeeding 1

Clinical Improvement Timeline

• Fever should resolve within 14-48 hours of starting treatment 1, 2, 4
• Parasitemia should clear within 36-48 hours with artesunate 4
• If symptoms persist beyond 72 hours, repeat blood smear and consider alternative diagnosis or treatment failure 1