SIDE EFFECTS
A variety of adverse reactions may develop during the initial phase (weekly
injections) of therapy or during maintenance treatment. Adverse reactions are
observed most frequently when the cumulative dose of Gold Sodium Thiomalate
administered is between 400 and 800mg. Very uncommonly, complications occur
days to months after cessation of treatment.
Cutaneous reactions: Dermatitis is the most common reaction.
Any eruption, especially if pruritic, that develops during treatment with
Gold Sodium Thiomalate should be considered a reaction to gold until
proven otherwise. Pruritus often exists before dermatitis becomes apparent,
and therefore should be considered a warning signal of impending cutaneous reaction.
The most serious form of cutaneous reaction is generalized exfoliative dermatitis
which may lead to alopecia and shedding of nails. Gold dermatitis may be aggravated
by exposure to sunlight or an actinic rash may develop.
Mucous membrane reactions: Stomatitis is the second most common
adverse reaction. Shallow ulcers on the buccal membranes, on the borders of
the tongue, and on the palate or in the pharynx may occur as the only adverse
reaction, or along with dermatitis. Sometimes diffuse glossitis or gingivitis
develops. A metallic taste may precede these oral mucous membrane reactions
and should be considered a warning signal.
Conjunctivitis is a rare reaction.
Renal reactions: Gold may be toxic to the kidney and produce
a nephrotic syndrome or glomerulitis with hematuria. These renal reactions are
usually relatively mild and subside completely if recognized early and treatment
is discontinued. They may become severe and chronic if treatment is continued
after onset of the reaction. Therefore, it is important to perform a urinalysis
before every injection, and to discontinue treatment promptly if proteinuria
or hematuria develops.
Hematologic reactions: Blood dyscrasia due to gold toxicity is
rare, but because of the potential serious consequences it must be constantly
watched for and recognized early by frequent blood examinations done throughout
treatment. Granulocytopenia; thrombocytopenia, with or without purpura; hypoplastic
and aplastic anemia; and eosinophilia have all been reported. These hematologic
disorders may occur separately or in combinations.
Nitritoid and allergic reactions: Reactions of the “nitritoid
type” which may resemble anaphylactoid effects have been reported. Flushing,
fainting, dizziness and sweating are most frequently reported. Other symptoms
that may occur include: nausea, vomiting, malaise, headache, and weakness.
More severe, but less common effects include: anaphylactic shock, syncope,
bradycardia, thickening of the tongue, difficulty in swallowing and breathing,
and angioneurotic edema. These effects may occur almost immediately after injection
or as late as 10 minutes following injection. They may occur at any time during
the course of therapy and if observed, treatment with Gold Sodium Thiomalate
should be discontinued.
Miscellaneous reactions: Gastrointestinal reactions have been
reported, including nausea, vomiting, anorexia, abdominal cramps and diarrhea.
Ulcerative enterocolitis, which can be severe or even fatal, has been reported
rarely.
There have been rare reports of reactions involving the eye such as iritis,
corneal ulcers, and gold deposits in ocular tissues. Peripheral and central
nervous system complications have been reported rarely. Peripheral neuropathy,
with or without, fasciculations, sensorimotor effects (including Guillain-Barré
syndrome) and elevated spinal fluid protein have been reported. Central nervous
system complications have included confusion, hallucinations and seizures. Usually
these signs and symptoms cleared upon discontinuation of gold therapy.
Hepatitis, jaundice, with or without cholestasis, gold bronchitis, pulmonary
injury manifested by interstitial pneumonitis and fibrosis, partial or complete
hair loss and fever have also been reported.
Sometimes arthralgia occurs for a day or two after an injection of Gold Sodium
Thiomalate; this reaction usually subsides after the first few injections.
Management Of Adverse Reactions
Treatment with Gold Sodium Thiomalate should be discontinued immediately when
toxic reactions occur. Minor complications such as localized dermatitis, mild
stomatitis, or slight proteinuria generally require no other therapy and resolve
spontaneously with suspension of Gold Sodium Thiomalate. Moderately severe skin
and mucous membrane reactions often benefit from topical corticosteroids, oral
antihistaminics, and soothing or anesthetic lotions.
If stomatitis or dermatitis becomes severe or more generalized, systemic corticosteroids
(generally, prednisone 10 to 40 mg daily in divided doses) may provide symptomatic
relief.
For serious renal, hematologic, pulmonary, and enterocolitic complications,
high doses of systemic corticosteroids (prednisone 40 to 100 mg daily in divided
doses) are recommended. The optimum duration of corticosteroid treatment varies
with the response of the individual patient. Therapy may be required for many
months when adverse effects are unusually severe or progressive.
In patients whose complications do not improve with high-dose corticosteroid
treatment, or who develop significant steroid-related adverse reactions, a chelating
agent may be given to enhance gold excretion. Dimercaprol (BAL) has been used
successfully, but patients must be monitored carefully as numerous untoward
reactions may attend its use. Corticosteroids and a chelating agent may be used
concomitantly.
Gold Sodium Thiomalate should not be reinstituted after severe or idiosyncratic
reactions.
Gold Sodium Thiomalate may be readministered following resolution of mild reactions,
using a reduced dosage schedule. If an initial test dose of 5 mg Gold Sodium
Thiomalate is well-tolerated, progressively larger doses (5 to 10 mg increments)
may be given at weekly to monthly intervals until a dose of 25 to 50 mg is reached.
DRUG INTERACTIONS
No information provided.