Indications

Zinc Acetate Dihydrate capsule therapy is indicated for maintenance treatment of patients with Wilson's disease who have been initially treated with a chelating agent.

Composition

Pharmacology

Wilson's disease (hepatolenticular degeneration) is an autosomal recessive metabolic defect in hepatic excretion of copper in the bile, resulting in accumulation of excess copper in the liver, and subsequently in other organs, including the brain, kidneys, eyes, bone, and muscles. In this disease, hepatocytes store excess copper, but when their capacity is exceeded copper is released into the blood and is taken up in extrahepatic sites, such as the brain, resulting in motor disorders (ataxia, tremors, speech difficulties) and psychiatric manifestations (irritability, depression, deterioration of work performance). Redistribution of excess copper in hepatocytes leads to hepatocellular injury, inflammation, necrosis, and eventual cirrhosis. Patients may present clinically with predominantly hepatic, neurologic, or psychiatric symptoms. The disease has been treated by restricting copper in the diet, and the use of chelating agents to bind free copper to reduce its toxicity and facilitate its excretion. The purpose of initial treatment of symptomatic patients with a chelating agent is to detoxify copper. Once the patient's symptoms have stabilized clinically, maintenance treatment begins. Clinical measures are used to determine whether the patient remains stable.

Dosage & Administration

The recommended adult dose is 50 mg as zinc three times daily. Since 25 mg t.i.d. is also an effective dose in children 10 years of age or older or in women who are pregnant, it may be advisable to use a dose of zinc to 25 mg three times a day, as long as the patient is compliant with therapy. The dose can be raised to 50 mg t.i.d. if monitoring indicates a lessening of control. Patients should take zinc acetate on an empty stomach, at least one hour before or two to three hours after meals.

Contraindications

Zinc Acetate Capsules are contraindicated in patients with known hypersensitivity to any of the components of the formulation.

Side Effects

The following adverse reactions associated with the use of zinc acetate were identified from postmarketing reports. Because these reactions were reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Gastrointestinal disorders: gastric irritation. Investigations: elevations of serum alkaline phosphatase, amylase, and lipase lasting from weeks to months suggesting pancreatitis; the levels usually return to high normal within the first one or two years of zinc therapy.

Pregnancy & Lactation

Pregnancy : Studies in pregnant women have not shown that zinc acetate or zinc sulfate increases the risk of fetal abnormalities if administered during all trimesters of pregnancy. If this drug is used during pregnancy, the possibility of fetal harm appears remote. Because studies cannot rule out the possibility of harm, however, zinc acetate should be used during pregnancy only if clearly needed. While zinc acetate should be used during pregnancy only if clearly needed, copper toxicosis can develop during pregnancy if anti-copper therapy is stopped. Lactation : Zinc does appear in breast milk and zinc-induced copper deficiency in the nursing baby may occur. Therefore, it is recommended that women on zinc therapy not nurse their babies.

Precautions & Warnings

Zinc acetate is not recommended for the initial therapy of symptomatic patients because of the delay required for zinc-induced increase in enterocytic metallothionein and blockade of copper uptake. Symptomatic patients should be treated initially, using chelating agents. During initial therapy, neurological deterioration may occur as stores of copper are mobilized. Once initial therapy has been completed, and the patient is clinically stable, maintenance treatment with zinc acetate can be considered, but patients may be continued on initial therapy as clinically indicated.

Therapeutic Class

Storage Conditions

Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.