Posted by Sunnely on July 16, 2000, at 21:41:01
In reply to melarill, posted by laurai on July 16, 2000, at 16:44:47
> I haven't slept in 10 days.
> The only thing that works at this point is Melarill and
> my doctor is afraid of TD.Laurai,
Virtually all older antipsychotics have been reported to cause TD including Mellaril (thioridazine). It appears that there is less risk of TD with the newer antipsychotics although there are now case reports coming in with risperidone use.
The dose and duration of antipsychotic use has a direct correlation with the development of TD. In a study done by Kane and others, 1988 - the incidence (rate of occurrence of new cases in a specified time) of TD increases as the length of antipsychotic treatment increases. For the first several years, this progression is linear as follows:
5% after 1 year
10% after 2 years
15% after 3 years
19% after 4 years
26% after 6 years
TD developing in a person taking Mellaril is not the only major concern with the use of this drug. The other potentially serious problem pertains to its effect on the heart. Mellaril has been shown to cause electrocardiogram (ECG) abnormality (prolong QTc interval) which can lead to potentially fatal irregular heart rhythm known as "torsades des pointes" and sudden death.
The US FDA has recently asked the maker of Mellaril, Novartis, to update the labeling for Mellaril to warn of potentially life-threatening side effects. As as a result, Mellaril is now indicated only for patients with schizophrenia who either cannot tolerate other antipsychotic drugs or who fail to respond to them, Novartis said.
In addition to changing Mellaril's label, Novartis will also send letters to about 360,000 US doctors and 60,000 pharmacies apprising them of the FDA's new position on the drug, and asking them to share the information with their patients. The letters will also advise that "switching to a different antipsychotic agent should be considered."
This warning should also apply to mesoridazine (Serentil) which is an active metabolite of Mellaril.
On a similar note, pimozide (Orap), another antipsychotic drug which is also approved for treatment of Tourette's syndrome, has also been reported to cause this potentially serious ECG abnormality. Dosage recommendation for this drug should be strictly complied with.
The FDA is very particular about drugs causing this potentially serious and fatal ECG abnormality. Three drugs were recently removed from the US market due to reports of sudden deaths from their use: Seldane (terfenadine), Hismanal (astemizole) both are nonsedating antihistamines, and Propulsid (cisapride) for GERD (gastroesophageal reflux disease). I believe there were over 100 sudden deaths reported with the use of Seldane and about 80 from Propulsid. One very promising antipsychotic, sertindole (Serlect), did not make it to the US shores because of findings of prolonged QTc during its clinical trials. This drug is available in the U.K as Serdolect (with ECG monitoring). Another very promising antipsychotic, Ziprasidone (Zeldox) is on holding pattern due to similar concern.
It should be noted that the tricyclic antidepressants (TCAs) have also been reported to cause similar ECG abnormality (prolonged QTc). However, anyone on tricyclic antidepressant should not abruptly stop their medication but periodic ECG tracing should be done. Also, if you are taking other meds along with Mellaril or TCAs, check with your doctor or pharmacist for any potentially serious drug-drug interactions. BTW, as a necessary precaution, avoid grapefruit juice.
Unless you have a diagnosis of schizophrenia and has been stable with Mellaril, you should not be taking this drug for other reasons. If your doctor practices in the US, he/she will soon receive a "Dear Doctor" letter from Novartis advising him/she of the heart warning.
References:
1) Kane JM, et. al: Tardive dyskinesia: Prevalence, incidence, and risk factors. Journal of Cllinical Psychopharmacology 1988;8(Suppl.):52S-56S.
2) News Labeling for Novartis' Mellaril Reflects Restricted Use, July 13, 2000, Reuters Health Information.
poster:Sunnely
thread:40661
URL: http://www.dr-bob.org/babble/20000708/msgs/40686.html