Question

A patient on haloperidol for psychosis develops fever, altered sensorium and labile hypertension. Drug useful in treating this patient is

• A. Cefotaxime
• B. Bromocriptine
• C. Largectil
• D. Propranolol

Hint:

Think about what class of drug can reverse haloperidol's effect on dopamine receptors.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
A patient on haloperidol develops fever, altered mental status and swinging high blood pressure, and we need the drug that helps treat this reaction.

Step 2: Key Formula or Approach:
Fever, altered sensorium, muscle rigidity and autonomic instability such as labile blood pressure, appearing in a patient on an antipsychotic like haloperidol, is the classic picture of Neuroleptic Malignant Syndrome (NMS). NMS is caused by sudden blockade of dopamine receptors, so the treatment logically works by restoring dopamine activity.

Step 3: Detailed Explanation:
Haloperidol is a potent dopamine D2 receptor blocker. Blocking dopamine too strongly in the hypothalamus and elsewhere in the brain can trigger NMS, presenting with high fever, rigidity, autonomic instability including labile hypertension, and altered consciousness.
Bromocriptine is a dopamine receptor agonist. By directly stimulating dopamine receptors, it reverses the dopamine blockade caused by haloperidol and is a standard treatment for NMS, along with supportive care and sometimes dantrolene for muscle rigidity.
Cefotaxime is an antibiotic and would only help if there were a proven infective fever, which is not suggested here since the clinical picture fits a drug reaction, not sepsis.
Largectil (chlorpromazine) is itself another dopamine blocking antipsychotic, so giving it would worsen NMS rather than treat it.
Propranolol is a beta blocker used for conditions like tremor or performance anxiety, and it does not correct the underlying dopamine blockade responsible for NMS.

Step 4: Final Answer:
Bromocriptine is the useful drug here, since it is a dopamine agonist that directly counters the dopamine receptor blockade caused by haloperidol in Neuroleptic Malignant Syndrome.