GOLD SODIUM THIOMALATE (thye-oh-mah'late) Myochrysine Classifications: gold compound Prototype: Aurothioglucose Pregnancy Category: C
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50 mg/mL injection
Water-soluble gold compound similar to aurothioglucose in actions and uses. Has immunomodulatory and antiinflammatory effects.
Action mechanism unclear. Drug appears to act by suppression of phagocytosis, altered immune responses, and possibly by inhibition
of prostaglandin synthesis.
Has immunomodulatory and antiinflammatory effects.
Selected patients (adults and juveniles) with acute rheumatoid arthritis.
Psoriatic arthritis, Felty's syndrome.
History of severe toxicity from previous exposure to gold or other heavy metals; severe debilitation; SLE, Sjögren's
syndrome in rheumatoid arthritis; renal disease; hepatic dysfunction, history of infectious hepatitis or hematologic disorders;
uncontrolled diabetes or CHF. Safe use during pregnancy (category C) and lactation is not established.
History of drug allergies or hypersensitivity, hypertension.
Rheumatoid Arthritis Adult: IM 10 mg wk 1, 25 mg wk 2, then 2550 mg/wk to a cumulative dose of 1 g (if improvement occurs, continue at 2550 mg
q2 wk for 220 wk, then q34 wk indefinitely or until adverse effects occur) Child: IM 10 mg test dose, then 1 mg/kg/wk or 2.55 mg for wk 1 and 2, followed by 1 mg/kg q14 wk (max: single dose 50 mg)
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Intramuscular
- Agitate vial before withdrawing dose to ensure uniform suspension.
- Give deep into upper outer quadrant of gluteus maximus with patient lying down. Patient should remain recumbent for at least
30 min after injection because of the danger of "nitritoid reaction" (transient giddiness, vertigo, facial flushing,
fainting).
- Observe for allergic reactions.
- Store in tight, light-resistant containers at 15°30° C (59°86° F). Do not use if any darker
than pale yellow.
CNS: Dizziness, syncope, sweating, flushing. CV: Bradycardia. GI: Hepatitis, metallic taste, stomatitis, nausea, vomiting. Hematologic:
Agranulocytosis, aplastic anemia, eosinophilia (all rare). Urogenital: Nephrotic syndrome, glomerulitis with hematuria, proteinuria.
Skin: Transient pruritus, erythema, dermatitis, fixed drug eruption, alopecia, shedding of nails, gray to blue pigmentation of skin (chrysiasis). Special Senses: Gold deposits in ocular tissues, photosensitivity. Body as a Whole: Peripheral neuritis, angioneurotic edema, interstitial pneumonitis, anaphylaxis (rare). Respiratory: Pulmonary fibrosis.
Drug:
antimalarials, immunosuppressants, penicillamine,
phenylbutazone increase risk of blood dyscrasias.
Absorption: Slowly and irregularly absorbed from IM site. Peak: 36 h. Distribution: Widely distributed, especially to synovial fluid, kidney, liver, and spleen; does not cross bloodbrain barrier; crosses
placenta. Metabolism: Not studied. Elimination: 6090% of dose ultimately excreted in urine; also eliminated in feces; traces may be found in urine for 6 mo. Half-Life: 3168 d.
Assessment & Drug Effects
- Lab tests: Prior to each injection, urinalysis for protein, blood, and sediment. Withhold drug and notify physician promptly
if proteinuria or hematuria develops. Also do baseline Hgb and RBC, WBC count, differential count, platelet count before initiation
of therapy and at regular intervals.
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Note: Rapid reduction in hemoglobin level, WBC count below 4000/mm3, eosinophil count above 5%, and platelet count below 100,000/mm3 signify possible toxicity.
- Interview and examine patient before each injection to detect occurrence of transient pruritus or dermatitis (both are common
early indications of toxicity), stomatitis (sore tongue, palate, or throat), metallic taste, indigestion, or other signs and
symptoms of possible toxicity. Interrupt treatment immediately and notify physician if any of these reactions occurs.
- Observe for allergic reaction, which may occur almost immediately after injection, 10 min after injection, or at any time
during therapy. Withhold drug and notify physician if observed. Keep antidote dimercaprol (BAL) on hand during time of injection.
Patient & Family Education
- Therapeutic effects may not appear until after 2 mo of therapy.
- Notify physician of rapid improvement in joint swelling; this is indicative that you are closely approaching drug tolerance
level.
- Use protective measures in sunlight. Exposure to sunlight may aggravate gold dermatitis.
- Notify physician at the appearance of purpura or ecchymoses; this is always an indication for doing a platelet count.
- Know possible adverse reactions and report any symptom suggestive of toxicity immediately to physician.
- Do not breast feed while taking this drug without consulting physician.