Dofetilide
Severe
Database
Clinical effect not specified
Source: DDInter
Drug reference
Tafenoquine
8-Aminoquinoline antimalarial (radical cure) · Antimalarial
START
Radical cure: 300 mg PO single dose with food (after CQ/CQ-eq course); prophylaxis 200 mg/day x3 then weekly
TYPICAL MAX
300 mg single dose (radical cure)
STOP IF
Severe haemolysis / symptomatic methaemoglobinaemia / hypersensitivity
WATCH
G6PD quantitative testing BEFORE dosing; Hb / urine colour; psychiatric
CDSCO approvedSchedule HATC P01BA07
KDIGO 2024 + manufacturer label
- ONSET
- 4h · absorption
- PEAK
- 13h · Tmax
- t½
- 2w · t½ ~14 d
- DURATION
- 1w · weekly
EXCRETION
Mainly biliary/faecal; minor renal
route + CYP
INTERACTIONS
5 major
SEVERE in our sources
PREGNANCY
Contraindicated (limited data; theoretical fetal haemolysis if fetus G6PD-deficient).
FDA category + note
Top interactionssee all 6 →
- DofetilideSevereDatabaseDDInter
- Nitrous AcidSevereDatabaseDDInter
- PrilocaineSevereDatabaseDDInter
- Methaemoglobin Inducing DrugsSevereDatabaseKimi deep-research + Cla
Mechanism
8-aminoquinoline with active metabolites that produce reactive oxygen species lethal to Plasmodium hypnozoites in the liver — provides radical cure of P. vivax / P. ovale relapsing malaria; activity against hepatic and erythrocytic stages.
Indications
Radical cure of Plasmodium vivax malaria (after chloroquine treatment of the acute infection, in G6PD-normal adults)Prophylaxis of malaria (alternative to mefloquine/atovaquone-proguanil for travellers)
Dosing
- Adult
- Radical cure: 300 mg PO single dose (after chloroquine course). Prophylaxis: 200 mg PO once daily for 3 days starting 3 days before travel, then 200 mg once weekly while in malarious area, then 200 mg once 7 days after leaving.
- Pediatric
- ≥16 y: as adult; <16 not established.
- Renal adjustment
- Not studied in severe renal impairment.
- Hepatic adjustment
- Not studied in moderate–severe impairment.
- Geriatric
- Limited data.
- Max dose
- 300 mg single dose (radical cure); 200 mg/day or 200 mg/week (prophylaxis)
Pharmacokinetics
Onset
Hypnozoite kill over days
Peak effect
~12–15 h (Tmax with food)
Duration
~weeks (long terminal half-life supports weekly dosing)
Half-life
~14–15 days
Bioavailability
Increased ~50% with food
Protein binding
>99%
Metabolism
Hepatic CYP2D6 minor, plus other CYPs
Excretion
Mainly biliary/faecal; minor renal
Contraindications
- G6PD deficiency (severe haemolysis risk; quantitative testing required)
- Severe hypersensitivity
- Caution: psychiatric disorders, breastfeeding G6PD-deficient infants
Side effects
Common
Nausea/vomitingHeadacheDizzinessMethaemoglobinaemia (asymptomatic)Decreased haemoglobin
Serious
- Severe haemolytic anaemia (G6PD-deficient)
- Symptomatic methaemoglobinaemia (esp. NADH-MetHb-reductase deficiency)
- Psychiatric events (anxiety, abnormal dreams)
- Hypersensitivity / SJS
Pregnancy & lactation
Pregnancy
Contraindicated (limited data; theoretical fetal haemolysis if fetus G6PD-deficient).
Lactation
Avoid breastfeeding G6PD-deficient infants; otherwise weigh risk.
Drug interactions
Nitrous Acid
Severe
Database
Clinical effect not specified
Source: DDInter
Prilocaine
Severe
Database
Clinical effect not specified
Source: DDInter
Methaemoglobin Inducing Drugs
Severe
Database
Additive methaemoglobinaemia
Avoid combination
Source: Kimi deep-research + Cla
Other 8 Aminoquinolines
Severe
Database
Duplicate therapy + additive haemolysis
Do not co-administer
Source: Kimi deep-research + Cla
Oct2
Moderate
Database
Tafenoquine inhibits OCT2 / MATE
Monitor metformin levels / clinical effect
Source: Kimi deep-research + Cla
6 additional unreviewed or low-confidence interactions hidden because their provenance or source detail is insufficient.
Related guidelines
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Textbook-sourced·Sources: KD Tripathi 7e, Goodman & Gilman 14e, Harrison 22e, Katzung·Updated: 2026-05-20·Cockpit curated: 2026-05-20