Thorazine, the brand-name version of chlorpromazine, was not pulled from the market because it was dangerous or ineffective. The manufacturer simply stopped selling it as a branded product, likely because the drug had long since gone generic and the brand name was no longer commercially viable. The FDA confirmed in a 2016 Federal Register notice that Thorazine “was not withdrawn from sale for reasons of safety or effectiveness.” Generic chlorpromazine is still FDA-approved, still manufactured, and still prescribed today.
That said, the story behind Thorazine’s decline from psychiatric mainstay to rarely prescribed medication is more complicated than a simple business decision. The drug’s serious neurological side effects, combined with the arrival of newer antipsychotics in the 1990s, steadily eroded its dominance over several decades.
The Brand Stopped, Not the Drug
When people hear “discontinued,” they often assume the FDA banned it. That’s not what happened. The original manufacturer stopped marketing Thorazine under its brand name, but the FDA explicitly ruled that this had nothing to do with safety concerns. The agency continues to approve generic versions of chlorpromazine, and pharmacies can still dispense it. The brand name disappeared from shelves the same way many older brand-name drugs do: once patent protection expires and cheaper generics flood the market, there’s little financial incentive to keep selling the branded version.
Why Doctors Moved Away From Chlorpromazine
Even though chlorpromazine remains available, it’s prescribed far less often than it was during its peak decades. The main reason is its side effect profile, particularly the neurological problems it causes.
Chlorpromazine works primarily by blocking dopamine receptors in the brain. That mechanism is effective at reducing hallucinations and delusions, but dopamine also controls movement. Blocking it too aggressively causes a cluster of movement-related problems known as extrapyramidal symptoms: muscle rigidity, tremors, restlessness, and difficulty with fine motor control. Studies found these symptoms appeared in roughly 10% of patients taking chlorpromazine, and preventive medications given alongside it didn’t reduce that rate.
The most feared long-term consequence is tardive dyskinesia, a condition involving involuntary repetitive movements, often in the face, tongue, or jaw. Tardive dyskinesia can persist even after stopping the drug, and for some patients it becomes permanent. This risk alone made many psychiatrists hesitant to keep patients on chlorpromazine for years.
There’s also neuroleptic malignant syndrome, a rare but potentially fatal reaction involving high fever, severe muscle rigidity, altered mental status, and metabolic dysfunction. The risk increases at higher doses. One large cohort study found that patients on doses above 200mg in chlorpromazine equivalents had a 71% higher incidence of this syndrome compared to those on lower doses.
How Newer Antipsychotics Changed the Landscape
Starting in the 1990s, a new class of antipsychotics began reaching the market. These drugs, sometimes called atypical or second-generation antipsychotics, target multiple brain receptors rather than focusing narrowly on dopamine. That broader mechanism brought several practical advantages for patients.
The newer drugs are generally better at treating the “negative” symptoms of schizophrenia, things like social withdrawal, flat emotional expression, and difficulty with motivation, which chlorpromazine barely touches. They also tend to improve cognitive function more effectively. Perhaps most importantly, they carry a significantly lower risk of tardive dyskinesia. Among the newer options, the risk varies: some carry very low risk, while others with stronger dopamine-blocking activity still carry moderate risk, though generally less than chlorpromazine.
The movement-related side effects of older drugs like chlorpromazine weren’t just medically concerning. They made patients feel physically uncomfortable in ways that led many to stop taking their medication entirely. Muscle stiffness, restlessness, and loss of fine motor control create a miserable daily experience. When newer drugs offered the same benefit against psychosis with fewer of these problems, the shift was inevitable.
It’s worth noting that the superiority of newer antipsychotics isn’t as clear-cut as marketing once suggested. A Cochrane systematic review pointed out that comparison studies may have been biased because they pitted newer drugs against doses of chlorpromazine that were far higher than what’s now recommended. At appropriate medium doses, chlorpromazine performs respectably. But the perception had already shifted, and prescribing habits followed.
Where Chlorpromazine Is Still Used
Chlorpromazine hasn’t disappeared from medicine. It retains a handful of specific roles where it remains genuinely useful, sometimes irreplaceable.
- Intractable hiccups: Chlorpromazine is the only FDA-approved treatment for persistent hiccups lasting more than 48 hours, a condition that sounds minor but can be debilitating and even dangerous.
- Severe nausea and vomiting: It’s still used to control nausea in surgical and other clinical settings.
- Acute intermittent porphyria: A rare metabolic condition where chlorpromazine helps manage symptoms.
- Tetanus: Used as an adjunct treatment to control muscle spasms.
- Migraine-related nausea: Sometimes prescribed off-label when other options fail.
Globally, chlorpromazine still plays a larger role in psychiatric care than it does in wealthier countries. Newer antipsychotics are considerably more expensive, and in many low- and middle-income settings, chlorpromazine remains one of the most widely used treatments for schizophrenia. The Cochrane review described it as a “gold standard” drug that is likely to remain a benchmark worldwide, despite its drawbacks.
What This Means if You Take Chlorpromazine
If you’re currently taking generic chlorpromazine, the discontinuation of the Thorazine brand doesn’t affect your prescription. Your pharmacy can still fill it with a generic version. The drug’s FDA approval remains fully intact, and new generic manufacturers can still receive approval to produce it.
Chlorpromazine at moderate doses remains a legitimate treatment option. The historical problems with the drug were partly a problem of dosing: for decades, psychiatrists prescribed it at levels now considered unnecessarily high, which amplified side effects without improving outcomes. At recommended modern doses, the risk profile is more manageable, though the movement-related side effects still make newer alternatives preferable for most patients starting antipsychotic treatment for the first time.