Phenothiazine Antiemetic — Hyperemesis Gravidarum Pregnancy: Safe in pregnancy — no confirmed teratogenicity; well-established use

Prochlorperazine (Nausea and Vomiting in Pregnancy)

Brand names: Stemetil, Buccastem

Adult dose

Dose: 5-10 mg oral three times daily; 3 mg buccal twice daily (Buccastem); 12.5 mg IM (acute)

Route: Oral / Buccal / Intramuscular

Frequency: Two to three times daily

Max: 40 mg/day oral

Second-line antiemetic for NVP when first-line (cyclizine, antihistamines) inadequate. Buccal formulation useful when vomiting prevents oral tablet retention

Paediatric dose

Dose: Not applicable in this obstetric context N/A/kg

Route: Oral / Buccal

Frequency: N/A

Max: N/A

Maternal medication

Dose adjustments

Renal

Use with caution

Hepatic

Avoid in hepatic impairment

Paediatric weight-based calculator

Patient weight (kg)

Maternal medication

Clinical pearls

RCOG Green-top 69 (2024): Prochlorperazine is second-line antiemetic in NVP — safe in pregnancy with established use; extrapyramidal reactions more common in young women at higher doses
Acute dystonic reaction: may occur with IM or oral doses — treat with procyclidine 5 mg IV/IM or diphenhydramine; more common in women under 40
Buccal absorption (Buccastem 3 mg): useful when tablet vomiting prevents oral retention — dissolves on gum; adequate absorption even with significant vomiting
No teratogenicity signal: widely used in pregnancy for decades; RCOG and NICE consider it safe throughout pregnancy
QT prolongation: avoid if patient on other QT-prolonging drugs or has hypokalaemia (common in hyperemesis)

Contraindications

Parkinson's disease
Bone marrow suppression
QT prolongation

Side effects

Extrapyramidal effects (dystonia, akathisia — especially in young women)
Sedation
QT prolongation
Postural hypotension

Interactions

QT-prolonging drugs (additive)
Antihypertensives (enhanced hypotension)
Lithium (additive neurotoxicity)

Monitoring

Extrapyramidal symptoms
Blood pressure (postural)
QTc if risk factors

Reference: BNFc; BNF 90; RCOG Green-top 69 (Hyperemesis Gravidarum 2024). Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators