Haloperidal (Haldol)

Question 1

Drug Classification

Answer 1

Butyrophenone Antipsychotic/Neuroleptic

Question 2

Mechanism of Action

Answer 2

Mesolimbic D1/D2 antagonist ->depresses release of hypothalamic and hypophyseal hormones; depresses the reticular activating system, thus affecting basal metabolism, body temperature, wakefulness, vaso motor tone and emesis

Question 3

Pharmacokinetics

Answer 3

Onset of Action- 30-45 minutes
Peak Effects- 10-20 minutes
Duration of Effects- varies
Half-Life- 3-35 hours

Question 4

Indications/Field Use

Answer 4

Acute psychosis episode

Question 5

Contraindications

Answer 5

• CNS depression (alcohol/drugs etc.)

- Agitation secondary to shock or hypoxia

Question 6

Side Effects/Adverse Reactions

Answer 6

EPS
Insomnia/Restlessness/Drowsiness
Seizures/Dry mouth/Constipation
Respiratory Depression
Tachycardia/Hypotension/Prolonged QT syndrome: Torsades

Question 7

Dose

Answer 7

Adult:
5mg IM q 4-8 hours PRN
Pedi:
1-3mg IM q 4-8 hours PRN, MAX 0.15mg/kg/day

Question 8

Precautions

Answer 8

• May impair physical and mental abilities
• May cause orthostatic hypotension
• May cause EPS or dystonic reactions

Question 9

Drug-Drug Interactions

Answer 9

• Caution in patients taking lithium- May cause encephalopathic syndrome (irreversible brain damage)
• May increase chances of hypotension when taken with anti hypertensives
• Additive effects with depressants and other anti-psychotics- increased CNS depression