Plaquenil

Plaquenil [pla´kwĕ-nil]

trademark for a preparation of hydroxychloroquine, an antiinflammatory and antiprotozoal agent used for treatment of malaria, lupus erythematosus, rheumatoid arthritis, and giardiasis.

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hydroxychloroquine sulfate

Plaquenil

Pharmacologic class: 4-aminoquinolone

Therapeutic class: Antimalarial, antirheumatic, anti-inflammatory (disease-modifying)

Pregnancy risk category C

FDA Boxed Warning

• Familiarize yourself completely with contents of the manufacturer's package insert before administering or prescribing this drug.

Action

Unknown. Thought to interfere with inhibition of protein synthesis and DNA replication, leading to parasitic death.

Availability

Tablets: 200 mg (155 mg base); 200 mg hydroxychloroquine sulfate is equivalent to 155 mg of hydroxychloroquine base

⊘Indications and dosages

➣ Malaria prophylaxis (dosages expressed as mg of base)

Adults: 310 mg P.O. q week, starting 1 to 2 weeks before entering endemic area and continuing for 4 weeks after leaving area

Children: 5 mg/kg P.O. q week, starting 1 to 2 weeks before entering endemic area and continuing for 4 weeks after leaving area

➣ Acute malarial attack (dosages expressed as mg of base)

Adults: Initially, 620 mg P.O., then 310 mg 6 hours, 24 hours, and 48 hours later

Children: Initially, 10 mg/kg P.O., then 5 mg/kg 6 hours, 24 hours, and 48 hours later

➣ Rheumatoid arthritis

Adults: 400 to 600 mg/day P.O. for 4 to 12 weeks, then reduced by 50%

➣ Systemic lupus erythematosus

Adults: 400 mg P.O. once or twice daily for several months, then reduced to 200 to 400 mg daily, depending on response

Contraindications

• Hypersensitivity to drug or chloroquine
• Retinal or visual field changes
• Long-term therapy in children

Precautions

Use cautiously in:
• hepatic or renal impairment, G6PD deficiency, psoriasis, bone marrow depression, alcoholism
• obese patients
• pregnant or breastfeeding patients
• children.

Administration

• Give with food or milk.
• For malaria prophylaxis, schedule doses on same day each week.

Route	Onset	Peak	Duration
P.O.	Unknown	2-4.5 hr	Unknown

Adverse reactions

CNS: anxiety, apathy, confusion, fatigue, headache, psychoses, mood swings, irritability, neuromyopathy, peripheral neuritis, seizures

CV: ECG changes, hypotension

EENT: visual disturbances, retinopathy, keratopathy, ototoxicity, tinnitus

GI: nausea, vomiting, diarrhea, abdominal cramps, anorexia

Hematologic: leukopenia, agranulocytosis, aplastic anemia, thrombocytopenia

Hepatic: jaundice, hepatotoxicity

Musculoskeletal: muscle weakness

Skin: dermatoses, rash, pruritus, pigmentation changes, pleomorphic skin eruption, worsened psoriasis, alopecia, bleaching of hair

Other: weight loss

Interactions

Drug-drug. Aluminum salts, kaolin, magnesium salts: decreased hydroxychloroquinine absorption

Cimetidine: decreased hepatic metabolism of hydroxychloroquinine

Hepatotoxic drugs: increased risk of hepatotoxicity

Drug-diagnostic tests. Granulocytes, hemoglobin, platelets: decreased values

Drug-behaviors. Sun exposure: exacerbation of drug-induced dermatoses

Patient monitoring

☞ Monitor for signs and symptoms of overdose, such as nausea, vomiting, drowsiness, visual disturbances, cardiovascular collapse, and seizures.
• Watch for adverse reactions.

Patient teaching

• Advise patient to take with food or milk.
☞ Instruct patient to immediately report such adverse reactions as vision changes, nausea, vomiting, drowsiness, mental changes, mood swings, headache, ringing in ears, muscle weakness, rash, bleeding, bruising, and yellowing of skin and eyes.
• In long-term therapy, advise patient to have regular eye exams.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.

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Plaquenil ®

Hydroxychloroquine sulfate, see there