Chloroquine side effects
Reading File
Finding Sources
Searching PubMed
chloroquine AND adverse effects
Searching the Web
chloroquine prescribing information adverse reactions FDA label
Reading File
Reading File
Reading File
Common side effects of chloroquine, especially at treatment doses, include:
- Nausea, vomiting, abdominal upset or diarrhea
- Headache, dizziness
- Itching (pruritus), rash, or hives
- Blurred vision or visual disturbance
- Skin, nail-bed, or mouth-pigment darkening with longer-term use
Important but less common effects
- Eye toxicity: Retinal damage can cause persistent visual-field changes or loss of vision, particularly with prolonged use or a high cumulative dose. Report blurred vision, difficulty reading, missing areas of vision, or altered color vision promptly. Regular eye assessment is appropriate during extended therapy. Lippincott Illustrated Reviews: Pharmacology, pp. 1171-1172; Kanski's Clinical Ophthalmology, p. 2342.
- Heart rhythm effects: Chloroquine can prolong the QT interval, raising the risk of dangerous arrhythmias. The risk is higher with other QT-prolonging medicines or low potassium/magnesium. A 2024 systematic review/meta-analysis also evaluated this association (PubMed PMID 38922589).
- Neurologic effects: Mood or behavioral changes, confusion, seizures, and rarely psychosis can occur.
- Low blood sugar: Sweating, shaking, hunger, dizziness, or faintness may signal hypoglycemia.
- Blood, muscle, liver effects: Rarely, blood-cell abnormalities, muscle weakness, cardiomyopathy, or liver injury can occur.
Get urgent medical help for fainting, palpitations, chest pain, seizures, severe confusion, severe rash/swelling, or sudden vision changes. Overdose is an emergency: chloroquine has a narrow safety margin and may rapidly cause low blood pressure, dangerous arrhythmias, seizures, coma, and cardiac arrest. Goodman & Gilman’s The Pharmacological Basis of Therapeutics, p. 1316.
Do not stop a prescribed course without contacting the prescriber, but seek advice promptly if you develop concerning symptoms.
Why hypoglycemia
Reading File
Finding Sources
Searching PubMed
chloroquine AND hypoglycemia
Searching the Web
chloroquine hypoglycemia mechanism insulin secretion FDA chloroquine label
Chloroquine can lower blood glucose because it has an insulin-like glucose-lowering effect. The mechanism is not fully settled, but it appears to:
- Increase insulin secretion from pancreatic beta cells
- Reduce insulin breakdown/clearance, so insulin remains active longer
- Possibly improve how strongly tissues respond to insulin
This can happen even in people without diabetes, and is more likely or more severe if someone is also taking insulin or diabetes tablets, has poor food intake/vomiting, kidney or liver impairment, or has malaria itself. The FDA labeling warns that chloroquine-related hypoglycemia can be severe enough to cause loss of consciousness, with or without antidiabetic treatment, as summarized by DailyMed.
Symptoms include sweating, tremor, hunger, dizziness, palpitations, confusion, blurred vision, or fainting. If these occur, take a fast sugar source if the person is awake and able to swallow, check glucose if possible, and seek urgent medical help for severe symptoms, confusion, seizure, or unconsciousness.
This is a shared conversation. Sign in to Orris to start your own chat.