hydroxychloroquine, Plaquenil

 Indications

Treatment of uncomplicated malaria in geographic areas

where chloroquine-resistance is not reported. Prophylaxis

of malaria in geographic areas where chloroquine-

resistance is not reported. Treatment of acute

and chronic rheumatoid arthritis. Treatment of chronic

discoid lupus erythematosus and systemic lupus erythematosus.

Action

Inhibits protein synthesis in susceptible organisms by

inhibiting DNA and RNA polymerase. Therapeutic

Effects: Death of plasmodia responsible for causing

malaria. Also has anti-inflammatory properties. Spectrum:

Active against chloroquine-sensitive strains of:

Plasmodium falciparum, Plasmodium malariae, a-

Plasmodium ovale, and Plasmodium vivax.

Pharmacokinetics

Absorption: Highly variable (31–100%) following

oral administation.

Distribution: Widely distributed; high concentrations

in RBCs; crosses the placenta; excreted into breast

milk.

Metabolism and Excretion: Partially metabolized

by the liver to active metabolites; partially excreted unchanged

by the kidneys.

Half-life: 40 days.

TIME/ACTION PROFILE (blood levels)

ROUTE ONSET PEAK DURATION

PO rapid† 1–2 hr days–weeks

†Onset of antirheumatic action may take 6 wk.

Contraindications/Precautions

Contraindicated in: Hypersensitivity to hydroxychloroquine

or chloroquine; Previous visual damage

from hydroxychloroquine or chloroquine.

Use Cautiously in: Concurrent use of hepatotoxic

drugs; Hepatic impairment or alcoholism; Use of high

doses (5 mg/kg base), duration of use 5 yr, renal

impairment, concurrent use of tamoxifen or macular

disease (qrisk of retinopathy); G6PD deficiency; Psoriasis;

Porphyria; Bone marrow depression; Obesity (determine

dose by ideal body weight); OB, Lactation:

Avoid use unless treating/preventing malaria or treating

amebic abscess; Geri:prenal function mayqrisk of

adverse reactions; Pedi: Safety and effectiveness for

chronic use not established.

Adverse Reactions/Side Effects

CNS: SEIZURES, SUICIDAL THOUGHTS/BEHAVIORS, aggressiveness,

anxiety, dizziness, fatigue, headache, irritability,

nightmares, personality changes, psychoses.

EENT: corneal deposits, nystagmus, retinopathy, tinnitus,

vertigo, visual disturbances. CV: HF, TORSADE DE

POINTES, heart block, QT interval prolongation. Endo:

hypoglycemia. GI: HEPATOTOXICITY, abdominal pain,

anorexia, diarrhea,qliver enzymes, nausea, vomiting. 

Derm: DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC

SYMPTOMS (DRESS), ERYTHEMA MULTIFORME, STEVENS-

JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS,

acute generalized exanthematous pustulosis, alopecia,

hair color changes, hyperpigmentation, photosensitivity,

pruritus, rash, urticaria. Hemat: AGRANULOCYTOSIS,

APLASTIC ANEMIA, leukopenia, thrombocytopenia. Metab:

pweight. Neuro: ataxia, dyskinesia, dystonia,

neuromyopathy, peripheral neuritis, tremor. Resp:

PULMONARY HYPERTENSION, bronchospasm. Misc: ANGIOEDEMA.

Interactions

Drug-Drug: Concurrent use of other QT intervalprolonging

drugs mayqrisk of torsade de pointes.

Mayqthe risk of hepatotoxicity when administered with

hepatotoxic drugs. Mayqrisk of hypoglycemia when

used with antidiabetic agents. Use with mefloquine

mayqrisk of seizures. Antacids may bind to andpthe

absorption of hydroxychloroquine; separate administration

by 4 hr. Cimetidine mayqlevels; avoid concurrent

use. Urinary acidifiers mayqrenal excretion.

Mayqlevels of digoxin or cyclosporine.

Route/Dosage

200 mg hydroxychloroquine sulfate155 mg of hydroxychloroquine

base.

Malaria

PO (Adults): Prophylaxis—400 mg sulfate (310 mg

base) once weekly; start 2 wk prior to entering malarious

area; continue for 4 wk after leaving area. Treatment—

800 mg sulfate (620 mg base), then 400 mg

sulfate (310 mg base) at 6 hr, 24 hr, and 48 hr after

initial dose.

PO (Children 31 kg): Prophylaxis—6.5 mg/kg

sulfate (5 mg/kg base) (not to exceed 400 mg sulfate

[310 mg base]) once weekly; start 2 wk prior to entering

malarious area; continue for 4 wk after leaving

area. Treatment—13 mg/kg sulfate (10 mg/kg base)

(not to exceed 800 mg sulfate [620 mg base]) initially,

then 6.5 mg/kg sulfate (5 mg/kg base) (not to exceed

400 mg sulfate [310 mg base]) at 6 hr, 24 hr, and 48

hr after initial dose.

Rheumatoid Arthritis

PO (Adults): 400–600 mg sulfate (310–465 mg

base) per day in 1–2 divided doses; once adequate response

obtained, maypdose to maintenance dose of

200–400 mg sulfate (155–310 mg base) per day in

1–2 divided doses.

Lupus Erythematosus

PO (Adults): 200–400 mg sulfate (155–310 mg

base) per day in 1–2 divided doses.

Availability (generic available)

Tablets: 200 mg sulfate (155 mg base). Cost: Generic—$

14.88/100.