CAMOQUIN HYDROCHLORIDE
Clinical safety rating
cautionComprehensive clinical and safety monograph for CAMOQUIN HYDROCHLORIDE (CAMOQUIN HYDROCHLORIDE).
Amodiaquine hydrochloride is a 4-aminoquinoline compound that acts as a blood schizonticide. It inhibits heme polymerase, leading to accumulation of toxic heme-iron complexes in the parasite's food vacuole, disrupting membrane function and parasite replication.
| Metabolism | Primarily metabolized in the liver by CYP2C8 to the active metabolite desethylamodiaquine. Also undergoes N-oxidation and conjugation. |
| Excretion | Primarily hepatic metabolism (approx. 60-70%) with metabolites excreted in bile and feces; renal excretion of unchanged drug accounts for <5% of the dose. Fecal elimination accounts for ~20-30% of the dose, with minor biliary contribution. |
| Half-life | Terminal elimination half-life ranges 9–21 days (mean ~14 days) due to extensive tissue binding; clinical context: steady-state achieved after 4–6 weeks, prolonged half-life allows weekly dosing for malaria prophylaxis. |
| Protein binding | Approximately 90% bound to plasma proteins, mainly albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Mean Vd ~100–300 L/kg (extremely large due to extensive tissue sequestration, especially in erythrocytes and liver); indicates deep tissue distribution. |
| Bioavailability | Oral bioavailability is approximately 75–85% (first-pass metabolism limited). |
| Onset of Action | Oral: 1–2 hours for detectable plasma levels; clinical antimalarial effect typically within 24–48 hours for acute attacks. |
| Duration of Action | Single oral dose: antimalarial effect persists for 14–21 days due to long half-life; full suppressive prophylaxis with weekly dosing. |
| Molecular Weight | 428.8 |
600 mg base (1 g salt) orally once weekly for prophylaxis; 600 mg base (1 g salt) initially followed by 600 mg base at 6, 24, and 48 hours for treatment of malaria.
| Dosage form | TABLET |
| Renal impairment | No specific guidelines; use with caution in severe renal impairment (CrCl <30 mL/min) due to potential accumulation. |
| Liver impairment | No specific guidelines; contraindicated in severe hepatic impairment (Child-Pugh class C) due to risk of toxicity. |
| Pediatric use | 5 mg base/kg (8.3 mg salt/kg) orally once weekly for prophylaxis; 10 mg base/kg (16.6 mg salt/kg) initially, followed by 5 mg base/kg at 6, 24, and 48 hours for treatment. |
| Geriatric use | Use with caution; consider lower initial doses and monitor for QT prolongation and neuropsychiatric effects due to age-related changes in clearance. |
| 1st trimester | Avoid in first trimester due to teratogenic potential (animal studies show skeletal malformations). |
| 2nd trimester | Use only if clearly needed; no well-controlled human studies, potential risk of fetal harm. |
| 3rd trimester | Use with caution near term; possible association with hemolytic anemia in G6PD-deficient fetus. |
Clinical note
Comprehensive clinical and safety monograph for CAMOQUIN HYDROCHLORIDE (CAMOQUIN HYDROCHLORIDE).
| Placental transfer | Crosses placenta; fetal concentrations similar to maternal. |
| Breastfeeding | Excreted into breast milk in small amounts; theoretical risk of hemolysis in G6PD-deficient infants; monitor infant for jaundice. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Amodiaquine (CAMOQUIN HYDROCHLORIDE) is not recommended due to limited data but animal studies show no teratogenicity at therapeutic doses. Second/third trimester: Generally considered safe for malaria treatment; no evidence of increased malformations. Overall risk category C: Risk cannot be ruled out. |
| Fetal Monitoring | Monitor for maternal hepatic toxicity (LFTs), blood dyscrasias (CBC), and severe cutaneous adverse reactions. Fetal monitoring includes ultrasound for growth restriction if used long-term. |
| Fertility Effects | No known adverse effects on fertility in males or females based on limited data. |
■ FDA Black Box Warning
Amodiaquine hydrochloride is associated with hepatotoxicity and agranulocytosis. Use is contraindicated in patients with previous adverse reactions to amodiaquine. Prolonged use for prophylaxis is not recommended due to risk of severe hepatic injury and blood dyscrasias.
| Serious Effects |
Hypersensitivity to amodiaquine or 4-aminoquinolinesPre-existing liver diseaseG6PD deficiencyPorphyria
| Precautions | Monitor liver function tests; discontinue if signs of hepatotoxicity (elevated transaminases, jaundice). Risk of agranulocytosis, neutropenia; monitor CBC. Caution in patients with G6PD deficiency (risk of hemolysis). Can cause QT prolongation; avoid in patients with pre-existing QTc prolongation or with other QT-prolonging drugs. Reduce dose in severe hepatic impairment. Use in pregnancy only if potential benefit outweighs risk (no adequate studies). |
| Food/Dietary | No specific food restrictions; however, administration with fatty meals may enhance absorption. Avoid grapefruit juice due to potential CYP2C8 inhibition. Maintain adequate hydration and caloric intake. |
| Clinical Pearls | Camoquin hydrochloride (amodiaquine) is an antimalarial agent related to chloroquine. It is active against erythrocytic stages of Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae. Not effective against exo-erythrocytic forms. Hepatic metabolism via CYP2C8; genetic variants may affect toxicity. Monitor for hepatotoxicity and agranulocytosis, especially with prolonged use. Contraindicated in patients with liver disease or history of psychosis. Use with caution in G6PD deficiency due to risk of hemolysis. |
| Patient Advice | Take exactly as prescribed; do not stop early even if feeling better. · May cause nausea; taking with food or milk can help reduce stomach upset. · Avoid alcohol while on this medication due to increased risk of hepatotoxicity. · Report any yellowing of skin or eyes, dark urine, severe fatigue, or unusual bleeding/bruising immediately. · Use effective contraception during treatment and for at least 1 month after the last dose. · Do not take with fever or other antimalarials unless directed by your physician. |
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