Hypersensitivity
Benperidol is contraindicated in patients with known hypersensitivity to the drug or any components of its formulation. Reactions may include rash, itching, swelling, and bronchospasm.
Parkinson’s disease
Benperidol can worsen symptoms of Parkinson’s disease due to its blockade of dopamine receptors. It is therefore contraindicated in patients with Parkinson’s disease.
Depression
Benperidol may worsen symptoms of depression and increase the risk of suicidal thoughts and behaviors. It should not be used in patients with severe depression or suicidal ideation.
Cardiovascular disease
Due its potential to prolong the QT interval, benperidol is contraindicated in patients with a history of cardiac arrhythmias, congestive heart failure, or recent myocardial infarction. It can also cause orthostatic hypotension, so should be avoided in patients with uncontrolled hypertension.
Seizures
Benperidol lowers the seizure threshold and should not be used in patients with epilepsy or a history of seizures.
Pheochromocytoma
In patients with pheochromocytoma, benperidol may lead to a hypertensive crisis due to release of catecholamines. It is therefore contraindicated in these patients.
Prostatic hyperplasia
Benperidol has anticholinergic effects and can worsen symptoms of prostatic hyperplasia like urinary retention. It should be avoided in patients with severe prostatic hypertrophy.
Dementia
In elderly patients with dementia, benperidol confers an increased risk of mortality, cerebrovascular events, and parkinsonism. Due to its significant safety risks, benperidol is contraindicated for behavioral problems in elderly dementia patients.
Hepatic impairment
Due to extensive metabolism of benperidol by the liver, reduced doses or dosage adjustments are recommended in patients with hepatic impairment. However, in severe liver disease the risks may outweigh potential benefits, so use is contraindicated.
Narrow-angle glaucoma
Benperidol can cause pupillary dilatation which may precipitate an attack of narrow-angle glaucoma. It is therefore contraindicated in patients with narrow angle glaucoma.
In summary, benperidol has many contraindications due to its risk of adverse effects in certain susceptible patient populations or disease states. Caution must be exercised if benperidol is used, and in many cases safer alternative treatments may be preferred, especially given the availability of newer atypical antipsychotics with fewer contraindications and side effects.