Plaquenil
In stock
200mg · 400mg
from 10,40 £
In brief
For some people with lupus or rheumatoid arthritis, hydroxychloroquine helps control symptoms by altering the immune response. Its effect builds over time, making it a treatment for ongoing disease control rather than immediate pain relief.
Pharmacology and mode of action
Hydroxychloroquine works by suppressing immune system activity and disrupting cellular processes. It accumulates in lysosomes, inhibiting autophagy and reducing inflammatory responses that drive autoimmune conditions. The pharmacokinetics show slow absorption with effects taking several weeks to manifest fully for rheumatoid arthritis or lupus. Metabolism occurs primarily in the liver, with renal excretion of metabolites.
- Potentially hazardous interactions occur with QT-prolonging drugs like azithromycin, increasing cardiac rhythm risks.
- Antacids reduce absorption significantly when taken within four hours of dosing.
- Though no direct alcohol interaction exists, drinking may worsen gastrointestinal side effects like nausea or stomach cramps.
Long half-life necessitates careful management in patients with kidney impairment where accumulation can occur. This mechanism explains both therapeutic benefits and toxicity risks requiring monitoring.
Approved uses and clinical applications
Plaquenil is licensed in the UK for specific conditions. For autoimmune disorders, it's prescribed for managing rheumatoid arthritis (including juvenile idiopathic arthritis) and systemic or discoid lupus erythematosus, often helping reduce the frequency of flare-ups; it is also licensed for skin conditions aggravated by sunlight. Hydroxychloroquine has also been used for malaria prevention, although this is not a licensed UK indication of Plaquenil. Some rheumatologists also use it off-label for Sjögren’s syndrome and dermatomyositis when considered clinically appropriate.
Among special populations, caution is warranted. During pregnancy, this medicine should be prescribed only if potential benefits outweigh risks - some rheumatologists continue it for stabilising active lupus. For children, autoimmune use requires paediatric specialist oversight according to NICE guidelines. Each case requires careful benefit-risk assessment.
Dosing guidelines and treatment protocols
| Condition | Adult dose | Paediatric dose |
|---|---|---|
| Malaria prevention | 400mg once weekly | 6.5mg/kg weekly (max 400mg) |
| Rheumatoid arthritis | 200-400mg daily | 3-7mg/kg daily (max 400mg) |
| Systemic lupus erythematosus | 200-400mg daily | 3-7mg/kg daily (max 400mg) |
Dosage adjustments may be needed for hepatic or renal impairment. Taking tablets with food improves tolerance by minimising stomach upset, even with standard dosing. For chronic autoimmune conditions, treatment often continues long-term unless toxicity develops. Regular monitoring includes annual ophthalmic examinations to screen for retinal toxicity, particularly after five years of continuous use. Consistent daily administration maintains therapeutic levels for managing rheumatological symptoms effectively.
Contraindications and precautions with Plaquenil
Plaquenil has specific situations where it must not be used. Absolute contraindications include existing maculopathy (retinopathy) of the eye and confirmed allergy to 4-aminoquinoline compounds. Several conditions require careful consideration before starting treatment. Important relative contraindications include G6PD enzyme deficiency, which risks haemolysis, cardiac rhythm abnormalities, psoriasis or porphyria history, and significant impairment of liver or kidney function.
Regular monitoring protocols help mitigate risks. Annual comprehensive eye exams by an ophthalmologist are essential to detect early retinal changes, as subtle damage can occur without initial symptoms. For patients with pre-existing heart conditions or cardiovascular risk factors, baseline and periodic ECGs are recommended to monitor QT interval prolongation. Those with hepatic impairment often require dose adjustments and liver function tests. Individuals with glucose-6-phosphate dehydrogenase deficiency need vigilant monitoring for anaemia symptoms.
Side effects and safety profile of Plaquenil
Common side effects include mild-to-moderate nausea, abdominal pain, headaches and skin rashes. These often resolve as the body adjusts, though persistent symptoms should be discussed with healthcare providers. Gastrointestinal discomfort sometimes leads to treatment discontinuation if dietary modifications or dosing with meals prove ineffective.
The medication carries serious potential risks requiring awareness. Retinal toxicity represents the most significant threat with long-term use, potentially leading to irreversible vision loss if undetected. QT prolongation and cardiomyopathy may develop, particularly in those with cardiac history. Unexpected hypoglycaemia has been documented, especially in diabetic patients or when combined with other glucose-lowering agents. The UK product information warns about cumulative retinal damage and the need for regular eye screening. Psychiatric reactions like mood changes or anxiety occur less frequently but warrant prompt reporting.
Administration and storage guidelines
Correct administration maximises effectiveness and safety. Tablets should be swallowed whole with water – not split or crushed. Consistency matters: establish fixed times for daily doses. If a dose is missed, take it as soon as you remember unless the next dose is due soon; never take a double dose, as this risks toxicity. During travel, maintain routines using phone reminders.
Proper storage preserves medication stability. Keep Plaquenil at controlled room temperature (15-30°C) in the original packaging which protects against moisture and light. Avoid bathrooms or cars where heat and humidity fluctuate significantly. Refrigeration or freezing causes deterioration. When transporting, retain tablets in blister packs rather than decanting. Dispose responsibly via pharmacy take-back schemes - unused medication shouldn't be kept beyond expiry.
Comparing Plaquenil to other treatment options
Several disease-modifying antirheumatic drugs (DMARDs) exist for autoimmune conditions like lupus or rheumatoid arthritis. Here's how Plaquenil compares to common alternatives:
| Medication | Efficacy | Key differences |
|---|---|---|
| Plaquenil (hydroxychloroquine) | High | Safest option during pregnancy, lower toxicity profile |
| Methotrexate | Higher | Requires frequent liver monitoring, alcohol restriction |
| Sulfasalazine | Moderate | Common gastrointestinal side effects |
UK rheumatologists often prescribe Plaquenil first for mild lupus or rheumatoid arthritis due to its favourable safety record. It's particularly recommended for women of childbearing age as it's compatible with pregnancy under specialist supervision. While methotrexate might be slightly more potent, its liver toxicity and alcohol restrictions make Plaquenil preferable when appropriate.
Common patient questions answered
Can I drink alcohol while taking Plaquenil?
Moderate alcohol consumption is generally acceptable, though excessive intake may worsen potential gastrointestinal discomfort. For patients with liver concerns, discuss thresholds with your specialist.
Does Plaquenil cause weight changes?
No significant evidence links Plaquenil to weight gain. Some patients report mild appetite reduction during initial treatment weeks, but this typically stabilises.
Safe usage guidelines
Maximise Plaquenil's effectiveness while minimising risks through proper administration:
- Timing: Take consistently with meals to reduce stomach upset
- Avoid: Antacids within 4 hours of dosing; prolonged sun exposure without protection
- Storage: Keep in original packaging at room temperature (15-30°C)
- Critical: Schedule annual ophthalmology exams - report vision changes immediately
Never adjust your dosage without consulting your rheumatologist. Sudden discontinuation risks disease flares. Always use sunscreen diligently as Plaquenil may increase photosensitivity.
