Promethazine Phenergan

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Promethazine (Phenergan)

• EMT Intermediates
• And
• Paramedics

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Class

• Antihistamine and antiemetic

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Description

• Promethazine is a phenothiazine derivative with
  potent antihistamine properties and
  anticholinergic properties.

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Mechanism of Action

• Promethazine possess sedative, antihistamine,
  antiemetic, and anticholinergic properties. It
  competitively blocks histamine receptors. The
  duration of action of Promethazine is 4-6 hours.
  It is an effective and frequently used
  antiemetic. Promethazine, unlike hydroxyzine,
  can be given intravenously. It is often
  administered with analgesics, particularly
  narcotics, to potentiate their effect.

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Pharmacokinetics

• Onset
• IV 5 minutes
• IM 20 minutes
• Peak Effects
• Varies
• Duration 4-6 Hours
• Half-Life 10-14 Hours

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Indications

• Promethazine is used for nausea and vomiting,
  motion sickness, and sedation and to potentiate
  the effects of analgesics.

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Contraindications

• Promethazine is contraindicated in patients in
  comatose states and in those who have received a
  large amount of depressants. Also, it should not
  be administered to any patient with a history of
  hypersensitivity to the drug.

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Precautions

• Promethazine may impair mental and physical
  abilities. Care must be taken to avoid
  accidental intra-arterial injection. It should
  never be administered subcutaneously.
  Extrapyramidal symptoms (EPS) have been reported
  following Promethazine use. Diphenhydramine
  (Benadryl) should be available.

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Side Effects

• Sedation
• Blurred Vision
• Restlessness
• Drowsiness

• Bradycardia
• Dizziness
• Tachycardia

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Interactions

• The depressant effect on the central nervous
  system of narcotics, sedatives or hypnotics, and
  alcohol is potentiated by Promethazine. An
  increased incidence of EPS has been reported with
  Promethazine is administered to patients taking
  monamine oxidase inhibitors (MAOIs).

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Dosage

• WVEMS-Nausea and Vomiting
• Initial dose Standing Orders for Intermediates
  and Paramedic.
• May be repeated after 15 minutes.
• Online Orders required for Intermediates
• Standing Orders for Paramedics
• 12.5 mg IV or
• 25 mg IM

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Supplied

• Promethazine is supplied in 25 mg vials.