Promethazine (Phenergan)

Question 1

Generic/Trade Name

Promethazine

Answer 1

Phenergan

Question 2

Generic/Trade Name

Phenergan

Answer 2

Promethazine

Question 3

Promethazine (Phenergan)

Drug Classification:

Answer 3

Antiemetic

Question 4

Promethazine (Phenergan)

Mechanism of Action:

Answer 4

Long acting phenothiazine derivative with:

• antihistaminic
• antiserotonin
• anticholinergic
• local anesthetic action

Depression of CTZ in medulla for antiemetic effects

(The chemoreceptor trigger zone (CTZ) is an area of the medulla that receives inputs from blood-borne drugs or hormones, and communicates with the vomiting center to initiate vomiting - source:wiki)

Question 5

Promethazine (Phenergan)

Pharmacokinetics

Answer 5

Onset- 5 min IV, 20 min IM
Peak- Varies
Duration- 4-6 hrs
½ Life- 10-14 hrs

Question 6

Promethazine (Phenergan)

Indications & Contraindications

Answer 6

Indications:

• Nausea and vomiting
• Potentiate effects of analgesics (ex morphine)

Contraindications:

• Hypersensitivity
• Coma

Question 7

Promethazine (Phenergan)

Side Effects/Adverse Reactions:

Answer 7

Drowsiness, Sedation, Blurred vision, dizziness,

Tachycardia, bradycardia

Gangrene with extravasation

Dystonic reaction (Monster/Tree)

Question 8

Promethazine (Phenergan)

Adult & Pedi Dose:

Answer 8

(ADULT) 12.5-25 mg IV/IM/IO

(PEDI) 0.5 mg/kg IV/IM/IO

Question 9

Promethazine (Phenergan)

Precautions:

Answer 9

• Caution with impaired hepatic function, cardiovascular disease, asthma, and hypertension
• Dystonic reaction may occur, have diphenhydramine available

Question 10

Promethazine (Phenergan)

Drug-Drug Interactions:

Answer 10

Alcohol and CNS depressants add to CNS depression and anticholinergic effects