Drug therapy - Schizophrenia (essay help - introduction)

Hi ambergraver,

There is quite a bit of confusion in your post, but I'll do my best to clear things up. Not a bad effort though!

Drug Classes

First off is to understand that neuroleptic is a synonym for anti-psychotic, it isn't a separate class of drug. Neuroleptic is generally an older less used term and anti-psychotic is more commonly used in psychiatry these days.

Anti-psychotics/neuroleptics are traditionally divided into typical (first generation older agents) and atypical (second generation newer agents) drug classes. The main difference between these categories is their side effect profile, although more modern evidence is stating that the older agents aren't as bad as we initially thought they were (don't worry about that at your level though).

In terms of the side effect differences the main ones to comment on would be movement disorders (e.g. tardive dyskinesia and parkinsonism), specifically what are called extra-pyramidal side effects (EPSEs). You theoretically get less EPSEs with newer atypical agents.

Drugs and Drug Naming

You're using brand names when you are discussing drugs and you should be using generic chemical names. For example Clozaril is a brand of clozapine, but clozapine is the actual active drug. Prolixin again is a brand name of the drug fluphenazine. You're basically saying Coke and Pepsi when you should be saying Cola.

Clozapine and fluphenazine also aren't great examples of typical and atypical agents as they aren't used much in the UK. The best examples to use for each category are;

Typical agents - Haloperidol, chlorpromazine, flupentixol

Atypical agents - Olanzapine, quetiapine, risperidone, aripiprazole and amisulpride.

Clozapine is kind of an in-between drug and the therapy of last resort, so whilst it is an atypical agent it is a special one sort of in a category of its own.

Mechanism of Action

All anti-psychotics have D2 receptor blocking (antagonist) action and this is where their therapeutic action theoretically occurs. You're right that cloazpine is the dirtiest drug (chemically speaking) as it interacts with serotonin and acetylcholine receptors. Amisulpride is the cleanest action with the least serotonergic action. In reality almost every anti-psychotic drug interacts with dopamine, serotonin and acetylcholine receptors.

Aripiprazole is the funny one as it is a partial dopamine agonist, not a full agonist. For the sake of simplicity I'd generally avoid talking about this drug even though it is widely used.

Therapeutic Outcome

All anti-psychotic drugs are deemed to be equally effective in alleviating the positive symptoms of schizophrenia e.g. delusions, hallucinations.

Atypical agents are thought to be more effective in treating the negative symptoms (apathy, social withdrawal, poverty of thought action and speech) of schizophrenia, particularly clozapine. These are the marketed claims but the receptor profile does not suggest any betterment over typical agents.

Hope that helps!