Trientine

INDICATIONS AND USAGE Trientine hydrochloride capsules are indicated in the treatment of patients with Wilson's disease who are intolerant of penicillamine. Clinical experience with trientine hydrochloride capsules is limited and alternate dosing regimens have not been well-characterized; all endpoints in determining an individual patient's dose have not been well defined. Trientine hydrochloride capsules and penicillamine cannot be considered interchangeable. Trientine hydrochloride capsules should be used when continued treatment with penicillamine is no longer possible because of intolerable or life endangering side effects. Unlike penicillamine, trientine hydrochloride capsules are not recommended in cystinuria or rheumatoid arthritis. The absence of a sulfhydryl moiety renders it incapable of binding cystine and, therefore, it is of no use in cystinuria. In 15 patients with rheumatoid arthritis, trientine hydrochloride capsules was reported not to be effective in improving any clinical or biochemical parameter after 12 weeks of treatment. Trientine hydrochloride capsules are not indicated for treatment of biliary cirrhosis.

CLINICAL PHARMACOLOGY Introduction Wilson's disease (hepatolenticular degeneration) is an autosomal inherited metabolic defect resulting in an inability to maintain a near-zero balance of copper. Excess copper accumulates possibly because the liver lacks the mechanism to excrete free copper into the bile. Hepatocytes store excess copper but when their capacity is exceeded copper is released into the blood and is taken up into extrahepatic sites. This condition is treated with a low copper diet and the use of chelating agents that bind copper to facilitate its excretion from the body. Clinical Summary Forty-one patients (18 male and 23 female) between the ages of 6 and 54 with a diagnosis of Wilson's disease and who were intolerant of d-penicillamine were treated in two separate studies with trientine hydrochloride. The dosage varied from 450 to 2,400 mg per day. The average dosage required to achieve an optimal clinical response varied between 1,000 mg and 2,000 mg per day. The mean duration of trientine hydrochloride therapy was 48.7 months (range 2 to 164 months). Thirty-four of the 41 patients improved, 4 had no change in clinical global response, 2 were lost to follow-up and one showed deterioration in clinical condition. One of the patients who improved while on therapy with trientine hydrochloride experienced a recurrence of the symptoms of systemic lupus erythematosus which had appeared originally during therapy with penicillamine. Therapy with trientine hydrochloride was discontinued. No other adverse reactions, except iron deficiency, were noted among any of these 41 patients. One investigator treated 13 patients with trientine hydrochloride following their development of intolerance to d-penicillamine. Retrospectively, he compared these patients to an additional group of 12 patients with Wilson's disease who were both tolerant of and controlled with d-penicillamine therapy, but who failed to continue any copper chelation therapy. The mean age at onset of disease of the latter group was 12 years as compared to 21 years for the former group. The trientine hydrochloride group received d-penicillamine for an average of 4 years as compared to an average of 10 years for the non-treated group. Various laboratory parameters showed changes in favor of the patients treated with trientine hydrochloride. Free and total serum copper, SGOT, and serum bilirubin all showed mean increases over baseline in the untreated group which were significantly larger than with the patients treated with trientine hydrochloride. In the 13 patients treated with trientine hydrochloride, previous symptoms and signs relating to d-penicillamine intolerance disappeared in 8 patients, improved in 4 patients, and remained unchanged in one patient. The neurological status in the trientine hydrochloride group was unchanged or improved over baseline, whereas in the untreated group, 6 patients remained unchanged and 6 worsened. Kayser-Fleischer rings improved significantly duri

DOSAGE AND ADMINISTRATION Systemic evaluation of dose and/or interval between dose has not been done. However, on limited clinical experience, the recommended initial dose of trientine hydrochloride capsules is 500 to 750 mg/day for pediatric patients and 750 to 1,250 mg/day for adults given in divided doses two, three or four times daily. This may be increased to a maximum of 2,000 mg/day for adults or 1,500 mg/day for pediatric patients age 12 or under. The daily dose of trientine hydrochloride should be increased only when the clinical response is not adequate or the concentration of free serum copper is persistently above 20 mcg/dL. Optimal long-term maintenance dosage should be determined at 6 to 12 month intervals (see PRECAUTIONS , Laboratory Tests ). It is important that trientine hydrochloride capsules be given on an empty stomach, at least one hour before meals or two hours after meals and at least one hour apart from any other drug, food, or milk. The capsules should be swallowed whole with water and should not be opened or chewed.

ADVERSE REACTIONS Clinical experience with trientine hydrochloride has been limited. The following adverse reactions have been reported in a clinical study in patients with Wilson's disease who were on therapy with trientine hydrochloride: iron deficiency, systemic lupus erythematosus (see CLINICAL PHARMACOLOGY ). In addition, the following adverse reactions have been reported in marketed use: dystonia, muscular spasm, myasthenia gravis. Trientine hydrochloride is not indicated for treatment of biliary cirrhosis, but in one study of 4 patients treated with trientine hydrochloride for primary biliary cirrhosis, the following adverse reactions were reported: heartburn; epigastric pain and tenderness; thickening, fissuring and flaking of the skin; hypochromic microcytic anemia; acute gastritis; aphthoid ulcers; abdominal pain; melena; anorexia; malaise; cramps; muscle pain; weakness; rhabdomyolysis. A causal relationship of these reactions to drug therapy could not be rejected or established. To report SUSPECTED ADVERSE REACTIONS, contact Endo at 1-800-828-9393 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

WARNINGS Patient experience with trientine hydrochloride is limited (see CLINICAL PHARMACOLOGY ). Patients receiving trientine hydrochloride should remain under regular medical supervision throughout the period of drug administration. Patients (especially women) should be closely monitored for evidence of iron deficiency anemia.

CONTRAINDICATIONS Hypersensitivity to this product.

OVERDOSAGE There is a report of an adult woman who ingested 30 grams of trientine hydrochloride without apparent ill effects. No other data on overdosage are available.