prochlorperazine (Stemetil)

see also:

• phenothiazines
• migraine
• anti-emetics

• prochlorperazine is a phenothiazine antiemetic which is mainly used in the Rx of ED Mx of vertigo and BPV and severe migraine

• adverse effects are similar to all phenothiazines and include:
  • extrapyramidal reactions such as oculogyric crisis, dystonic reactions, akathisia such as oculogyric crises, akathisia, dystonic reactions and if used long term, irreversible tardive dyskinesia
  • sedation
  • hypotension and postural hypotension and thus increased risk of falls in the elderly
  • anticholinergic effects such as dry mouth, blurred vision, prostatism, narrow angle acute glaucoma, hyperthermia, impaired perspiration and constipation.
  • lowered seizure threshold
  • rarely, it may cause prolonged QTc, hepatic effects, blood dyscrasias, etc.

• PH adverse reactions to phenothiazines such as hepatic effects, blood dyscrasias
• bone marrow depression
• hypotension
• CNS depression (eg. drug overdose)

• avoid in those with PH extrapyramidal reactions
• PH neuroleptic malignant syndrome (NMS)
• elderly - falls risk, delirium risk
• renal impairment
• Parkinson's disease
• hypothyroidism
• phaechromocytoma
• myasthenia gravis
• prostatism
• hepatic impairment
• epilepsy or seizure risk (eg. brain tumour)
• risk of prolonged QTc - bradycardia, hypokalaemia, other drugs that prolong QTc, etc
• hypoparathyroidism with hypocalcaemia increases risk of dystonic reactions
• high dose or prolonged use - risk of irreversible tardive dyskinesia
• pregnancy, labour, lactation
• children < 2yrs old
• suspected Reye's syndrome
• diabetes
• hypothermia risk (eg. swimming in cold water)
• hyperthermia risk (eg. hot weather)
• thromboembolism risk eg. PH stroke
• use with other anti-muscarinic anticholinergic agents
• use with other sedatives
• use with pro-convulsants (eg steroids)
• interactions with anticonvulsants, warfarin, other medications

• usual oral dose: 5-10mg orally 2-4 times a day (adults can be given an initial 20mg dose orally and if necessary a further 10mg oral dose 2 hours later according to PMI)
• usual rectal dose: 25mg suppository can be followed by oral dose 6 hours later
• usual im dose: 12.5mg deep im injection can be followed by oral dose 6 hours later
• slow iv dose: 2.5-10mg can be given by slow iv injection or infusion with saline (max. adult rate 5mg/minute¹⁾).