The active ingredient, haloperidol, is a highly potent antipsychotic (neuroleptic) drug that is approved to treat acute mania, acute chronic schizophrenia and for tic disorders (Tourette’s syndrome). However, consumption of the drug is associated with severe side effects. These include long-term movement disorders and late dyskinesias.
Researchers from Lagos have now been able to show in animal models that the simultaneous administration of haloperidol and cannabidiol (CBD) could prevent these side effects.
How does Haloperidol work?
The nerve cells in the brain communicate via different neurotransmitters (messenger substances). These can be roughly divided into two groups: While some messenger substances such as norepinephrine have an activating, excitatory and stimulating effect, other messenger substances such as serotonin, the “happiness hormone”, trigger calming and attenuating effects.
Haloperidol is prescribed when an excess of the messenger substance, dopamine, is detected in patients. Dopamine is also known as the “happiness hormone”. An excess of this can trigger schizophrenia, psychosis, delusions and loss of reality.
The active substance haloperidol binds to the dopamine receptors and blocks them so that the dopamine signals are not transmitted. As a result, the high levels of dopamine normalise.
In Parkinson’s disease, patients show a lack of dopamine so that the body’s movement patterns are disturbed. Since haloperidol blocks the dopamine signals, movement disorders may also occur. These are known as extrapyramidal motor disorders and can manifest themselves in the form of an urge to move, restlessness and involuntary movements.
Haloperidol in combination with cannabidiol
The researchers investigated the effects of CBD on haloperidol-induced extrapyramidal motor disorders. There were a total of six experimental groups with rats receiving different combinations of oral cannabidiol with 5 mg/kg haloperidol.
The researchers concluded from the results that haloperidol in combination with CBD could alleviate motor impairments and prevent long-term movement disorders such as acute dystonic disorders.