
Butyrophenones
- Mechanism
- Dopamine receptor inhibition
Drug | Onset (IM) | Onset (IV) |
Haloperidol 5-10 mg | 20-60 min | 3-5 min |
Droperidol 5-10 mg | 15-30 min | 1-2 min |
- Effects
- Reduces psychotic symptoms
- Adverse Effects
- QTc prolongation, sedation, dystonia, akathisia
- Akathisia – restlessness 🡪 “worsening agitation”Â
- Dystonia – torticollis, tongue protrusion, laryngeal dystonia (respiratory sx, stridor, dysphagia)
- QTc prolongation, sedation, dystonia, akathisia
- Caution
- Neuroleptic malignant syndrome, Parkinson’s disease
- Controversies
- How significant is the QTc prolongation? Studies show…4-8 ms
- Combination therapy needed?Â
Calver et al, 2015
- ECG within 2 hours of droperidol in 1009 patients
- 1.3% of patients had abnormal QTc
- Of the 13 patients, 7 had pre-existing prolongation or other causes
- No cases of TdP
Harrigan et al, 2004
- Open-label, randomized, parallel-group trial of 183 patients
- Haloperidol increased QTc interval by 7.1 ms