Side Effects of Chloroquine Phosphate Tablets

Chloroquine phosphate tablets can be used to treat chloroquine-sensitive forms of malaria—including *Plasmodium falciparum*, *P. vivax*, and *P. malariae*—and for suppressive prophylaxis against malaria symptoms. They are also indicated for the treatment of extraintestinal amebiasis, connective tissue diseases, and photosensitivity disorders. However, chloroquine phosphate tablets have associated adverse effects. So, what are the side effects of chloroquine phosphate tablets? Let’s explore them below.

Adverse Effects of Chloroquine Phosphate Tablets

1. When used to treat malaria, oral administration of chloroquine phosphate tablets may commonly cause dizziness, headache, visual disturbances (e.g., blurred vision or photopsia), decreased appetite, nausea, vomiting, abdominal pain, diarrhea, pruritus, skin rash, and even exfoliative dermatitis, tinnitus, and irritability. Most of these reactions are mild and resolve spontaneously upon discontinuation of the drug.

2. When treating paragonimiasis, clonorchiasis, or connective tissue diseases, higher doses and longer treatment durations may lead to more severe adverse effects, including ocular toxicity. Characteristic findings include diffuse white granular deposits on the cornea, which typically resolve after drug discontinuation.

3. Prolonged use may cause mild retinal edema and pigment deposition, resulting in scotomata and impaired vision—effects that are irreversible.

4. Chloroquine phosphate may impair hearing. In pregnant women, high-dose exposure can cause congenital deafness, intellectual disability, hydrocephalus, and limb deformities in the fetus.

5. It may suppress the sinoatrial node, leading to cardiac arrhythmias and shock; in severe cases, Adams-Stokes syndrome may occur, potentially resulting in death.

6. Chloroquine phosphate tablets may induce drug-induced psychosis, leukopenia, purpura, rash, dermatitis, photoallergic or exfoliative dermatitis, psoriasis, premature graying or alopecia, neuromuscular pain, and mild, transient headache.

The above outlines the known adverse effects of chloroquine phosphate tablets. As a prescription-only medication, chloroquine phosphate must be used strictly under medical supervision; self-administration is strongly discouraged to avoid adverse reactions. We hope this information has been helpful to you.