I wasn't referring to simple dyskinesias caused by dopamine receptor antagonism, but actual neuronal death, MPTP, the similarly acting toxin, for example, was discovered accidentally, after a guy decided to knock himself up some of a synthetic opioid, an analog of pethidine (meperidine in the US), and whilst doing a batch, he shortcutted the process by heating to accelerate the reaction, resulting in a decarboxylation/dehydration reaction, turning the synthetic opioid, MPP, into MPTP, methylphenyltetrahydropyridine (forget the numbering system, CBF to look it up right now, I'm tired), which when he, and some other users shot it up, basically went and instantly permafried his nigrostriatal tract, leaving him more or less paralysed, due to an incredibly severe form of chemically-induced parkinsons. It appears from its history of use, that HPP+, the nasty haldol metabolite is less toxic, but certainly appears to be pretty bad news longterm. Ziprasidone is known for causing Q-T wave interval prolongation (interference with part of the electrophysiological depolarization-repolarization of pacemaker cells controlling the heart rate, as shown via ECG), you could try other neuroleptics, if you don't want off them altogether.
Or what about a muscle relaxer? a couple of things that helped me with myoclonic muscle twitches, although the docs labelled that a tic, I disagree, but nevertheless, one of us has to be right...were clonidine, and tizanidine, the former mainly a hypotensive agent used to treat high blood pressure, although also used as a calming agent in AD(H)D, similar to guanfacine, tizanidine is another relative of those two, less hypotensive potency but much more of a myorelaxant. Worked wonders for me, all those three work by acting as agonists of the alpha2 adrenoreceptor, one of the adrenergic autoreceptors (autoreceptors are presynaptic receptors acting for the vast majority of cases as negative feedback loops serving to decrease neurotransmitter release when stimulated, thus clonidine and friends act to decrease noradrenaline release)
I find it has a whole lot of benefits, since getting scripted it, less overloading tendency, less overstimulation, and much, much less motor twitching/myoclonus. Got scripted tizanidine as well, due to a longterm muscle spasm problem in my screwy leg and that just added to the effectiveness, although the latter is relatively short acting, and unsuitable in cases of severe liver disease)
