Posted by ed_uk on February 5, 2005, at 13:31:00
In reply to Tryptophan in the UK, posted by ed_uk on February 4, 2005, at 10:04:24
Hi,
EMS is a condition that was initially thought to be a side effect of tryptophan but was later found to be caused by contaminate tryptophan from Japan rather than the tryptophan itself. Up until yesterday, tryptophan was only available in the UK for patients who had registered with a monitoring service set up by Merck pharmaceuticals. The monitoring service was designed to monitor patients taking tryptophan for EMS. Since no cases of EMS occured, the monitoring service is no longer thought to be necessary. As a result, doctors can now prescribe tryptophan in the same way as all other prescription medicines. Tryptophan is still not available without a prescription in the UK. Also, up until yesterday, Merck would only allow people to take tryptophan if they had been severely depressed for at least two years. This rule no longer applies.
'Eosinophilia-myalgia syndrome.
In late 1989 the first notification linking the eosinophilia-myalgia syndrome with the use of tryptophan-containing products was made in the USA. There followed a number of similar published case reports from the USA, Europe, and Japan. Reviews of tryptophan-associated eosinophilia-myalgia syndrome have noted that by early 1990 over 1500 cases were known in the USA.
In early 1990 the Centers for Disease Control in the USA summarised the features and known reports concerning the syndrome. As the name implies the characteristic features are an intense eosinophilia together with disabling fatigue and muscle pain, although multisystem organ involvement and inflammatory disorders affecting the joints, skin, connective tissue, lungs, heart, and liver have also been recorded. Symptoms have generally developed over several weeks and the syndrome has occurred in patients who had been receiving tryptophan for many years previously with no untoward effect. In most patients slow and gradual improvement in the degree of eosinophilia and other clinical manifestations has followed the withdrawal of tryptophan, but in some patients the disease has progressed despite withdrawal and there have been fatalities. The inflammatory condition has necessitated the use of corticosteroids in some patients.
The eosinophilia-myalgia syndrome has been reported in patients taking both tryptophan-containing prescription products for depression and non-prescription dietary supplements for a number of disorders including insomnia, the premenstrual syndrome, and stress; it does not appear to have occurred in patients receiving amino-acid preparations containing tryptophan as part of total parenteral nutrition regimens. The recognition of this syndrome led to the withdrawal of tryptophan-containing products or severe restrictions being imposed upon their use in many countries during 1990.
Various theories were proposed as to the reason for the association of tryptophan with this syndrome. Confusion existed because the reports implicated a very wide range of products from different manufacturers. More recent evidence, however, appears to have confirmed that contaminated tryptophan has originated from a single manufacturer in Japan. Bulk tryptophan is imported from Japan for manufacture into finished pharmaceutical dosage forms and it was noted in one of these reports that a single product was often found to contain two or more lots of powdered tryptophan that were blended together during the production of tablets or capsules. Many trace contaminants have been found in batches of tryptophan associated with the syndrome. One contaminant has been identified as 1,1´-ethylidenebis(tryptophan). Its inclusion in bulk tryptophan powder appeared to coincide with alterations in the manufacturing conditions that involved a change in the strain of Bacillus amyloliquefaciens used in the fermentation process and a reduction in the amount of charcoal used for purification. Other investigations indicated the presence of bacitracin-like peptides in batches of the contaminated tryptophan. However, further work has provided only weak support for an association between the syndrome and any one particular contaminant and the causative agent remains to be confirmed. Nonetheless, since the syndrome only appeared to be associated with tryptophan from one manufacturer, tryptophan preparations were reintroduced in the UK in 1994.'
The tryptophan product available in the UK is called Optimax. Now that Optimax is considered to be safe, the monitoring service has been discontinued and psychiatrists are allowed to prescribe Optimax without restrictions.
Ed.
poster:ed_uk
thread:453062
URL: http://www.dr-bob.org/babble/20050202/msgs/453622.html