Drug reference

Primaquine

8-aminoquinoline antimalarial · Antimalarial (Hypnozoiticide)

Also known as Primaquine phosphate

START

Quantitative G6PD test FIRST; then 0.25–0.5 mg/kg/day base ×14 days with schizonticide

TYPICAL MAX

30 mg base/day (radical cure)

STOP IF

Haemolysis (dark urine, falling Hb), severe methaemoglobinaemia

WATCH

G6PD status before therapy, Hb/haemolysis signs, methaemoglobin if cyanosis

CDSCO approvedSchedule HJan AushadhiATC P01BA03

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 2h · absorption
PEAK: 2.5h · Cmax
t½: 6h · parent t½
DURATION: 1d · daily dosing

EXCRETION

Hepatic CYP2D6/MAO; renal metabolites

route + CYP

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

Contraindicated in pregnancy — defer radical cure, use weekly chloroquine prophylaxis until delivery

FDA category + note

Top interactionssee all 12 →

QuinacrineSevereTextbookHarrison 22e · p1741
AdalimumabSevereDatabaseDDInter
AmiodaroneSevereDatabaseDDInter
AmisulprideSevereDatabaseDDInter

Available in India

42 branded formulations and 1 fixed-dose combination. Look up specific brands in the Drugs workspace.

Jan Aushadhi — generic available at GoI pharmacies

Mechanism

Active metabolites generate reactive oxygen species disrupting mitochondrial function of Plasmodium liver-stage hypnozoites and gametocytes; the only widely used agent achieving radical cure of P. vivax/ovale and gametocytocidal activity.

Indications

Radical cure / anti-relapse of P. vivax and P. ovale malariaGametocytocidal (transmission-blocking) in P. falciparumPneumocystis jirovecii pneumonia (with clindamycin, alternative regimen)

Dosing

Adult: P. vivax/ovale radical cure: 0.25–0.5 mg/kg/day (≈15–30 mg base) for 14 days (with chloroquine/ACT). P. falciparum gametocytocidal: single 0.25 mg/kg. Test G6PD first.
Pediatric: 0.25–0.5 mg/kg/day base ×14 days (G6PD-tested).
Renal adjustment: No established adjustment; caution in significant impairment.
Hepatic adjustment: No specific adjustment; caution.
Geriatric: No specific adjustment; check G6PD.
Max dose: 30 mg base/day (radical cure); single 0.25 mg/kg for falciparum gametocytocidal

Pharmacokinetics

Onset

Antirelapse over the 14-day course

Peak effect

Cmax ~2–3 h

Duration

Course-based

Half-life

~4–7 h (parent)

Bioavailability

~96% (well absorbed)

Protein binding

~20%

Metabolism

Hepatic (CYP2D6 critical for activity; MAO to carboxyprimaquine)

Excretion

Renal (small unchanged); metabolites

Contraindications

Severe G6PD deficiency (haemolysis) — test before use
Pregnancy (unknown fetal G6PD status)
Concomitant other haemolytic/marrow-suppressive drugs
Hypersensitivity to primaquine

Side effects

Common

GI upset, abdominal cramps (take with food)HeadacheMild methaemoglobinaemiaPruritus

Serious

Acute haemolytic anaemia (G6PD deficiency)
Severe methaemoglobinaemia (NADH-methaemoglobin reductase deficiency)
Agranulocytosis/leukopenia (rare)
Cardiac arrhythmia (rare)

Pregnancy & lactation

Pregnancy

Contraindicated in pregnancy — defer radical cure, use weekly chloroquine prophylaxis until delivery

Lactation

Avoid unless infant G6PD-normal documented; small amounts in milk

Drug interactions

Quinacrine

Severe

Textbook

Increased toxicity of primaquine, potentially leading to severe adverse effects.

Not specified in the text, but likely contraindication or very cautious use with close monitoring.

Source: Harrison 22e · p1741

Adalimumab

Severe

Database