The reasoning: treatment principles (National Drug Policy on Malaria; orientation only, confirm current guidelines)
| Situation | Regimen (principle) |
|---|---|
| *P. vivax* | Chloroquine 25 mg base/kg over 3 days + primaquine 0.25 mg/kg/day × 14 days (radical cure); avoid primaquine in pregnancy, infants < 6 months (programme thresholds vary), G6PD deficiency (test where available; weekly regimen under supervision in mild deficiency per guidance) |
| *P. falciparum* (most of India) | ACT‑SP: artesunate 4 mg/kg/day × 3 days + sulfadoxine–pyrimethamine on day 1, + single‑dose primaquine on day 2 (gametocytocidal: 0.75 mg/kg in India's longstanding policy, while WHO recommends a single low dose of 0.25 mg/kg; follow the current national guideline) |
| P. falciparum (north‑eastern states) | ACT‑AL (artemether–lumefantrine) × 3 days + single‑dose primaquine, because of SP resistance |
| Mixed infection | ACT + 14‑day primaquine |
| Pregnancy | Pv: chloroquine (no primaquine); Pf: ACT in 2nd/3rd trimesters; 1st trimester per current guideline (quinine + clindamycin historically; WHO now permits AL) |
| Severe malaria | Injectable artesunate (2.4 mg/kg IV/IM at 0, 12, 24 h, then daily) → full oral ACT; pre‑referral rectal or IM artesunate at community level |