Psychosis as a possible side-effect of treatment with glatiramer acetate

Abstract

Multiple sclerosis (MS) is a common neurological disorder in younger adults. After an initial phase, which is characterized by complete or partial remission of neurological deficits (relapsing/remitting form), the illness enters a progressive phase with accumulation of neurological disability. Glatiramer acetate (GA, copolymer 1) is a new drug, which has recently been approved for the treatment of relapsing MS. GA is a synthetic mixture of relatively short polypeptides with a molecular weight between 4.7 and 10 kDa consisting of a random sequence of the four amino acids l-alanine, l-lysine, l-glutamic acid, and l-tyrosine. The substance is supposed to inhibit myelin-reactive T cells, to promote the induction of anti-inflammatory Th2 and CD8+ T cells, thus suppressing autoimmune responses in the CNS. Additional neuroprotective and repair mechanisms may be the result of local accumulation of GA-reactive T cells. In randomized, double-blind, placebo-controlled clinical trials the compound has been shown to reduce the relapse rate and to slow progression of disability in MS (Bornstein et al., 1991; Johnson et al., 2000). Side-effects of the drug were assessed, and GA was claimed as a well-tolerated drug (Johnson et al., 2001). Mild local injection site reactions occur in 90% of patients, while 15% of patients experience an immediate post-injection reaction with flushing, chest tightness, shortness of breath, palpitation and anxiety.