Drug therapy options for acute agitation in pregnant women

DrugInitial dosingOnsetaMajor adverse effectsb
Diphenhydramine25–50 mg PO, IV, or IM every 1–4 hours
Maximum 300 mg/day
PO: 15–30 minutes IM, IV: rapidSedation, anticholinergic effects
First-generation antipsychotics
Haloperidol5–10 mg PO, IV, or IM
Maximum 20 mg/day
PO: 2 –6 hours
IM, IV: 20–30 minutes
Extrapyramidal effect, dystonia, sedation, neuroleptic malignant syndrome, anticholinergic effects
Second-generation antipsychotics
Olanzapinec5–10 mg PO or IM
Maximum 20–30 mg/day
PO: 15 minutes to 4 hours
IM: 15–30 minutes
Sedation, orthostatic hypotension, extrapyramidal symptoms
Ziprasidone20 mg IM
Maximum 40 mg/day
IM: 15–30 minutesSedation, headache, nausea, extrapyramidal symptoms
Lorazepam0.5–2 mg PO, IV, or IMPO: 15–30 minutes
IM, IV: rapid
Sedation, respiratory depression
  • a Based on information in Zun LS. Evidence-based review of pharmacotherapy for acute agitation. Part 1: Onset of efficacy. J Emerg Med 2018; 54(3):364–374. doi:10.1016/j.jemermed.2017.10.011

  • b The US Food and Drug Administration no longer uses the letter-based risk categories. A synthesis of risks and benefits of medications in this table is available at

  • c Contraindicated in patients taking a benzodiazepine.

  • IM = intramuscular; IV = intravenous; PO = by mouth