QuestionQA
Concept
Chapter
#### Monitoring

The BNF advises to monitor lung function (in patients with a history of obstructive airway disease).

#### Overdoses

Overdosages with beta-blockers may cause cardiac effects such as bradycardia, hypotension, syncope, conduction abnormalities, and heart failure. Bradycardia is the most common arrhythmia, but some beta-blockers may induce ventricular tachyarrhythmias secondary to prolongation of QT interval (e.g. sotalol) or QRS duration (e.g. propranolol).
Non-cardiovascular effects include central nervous system effects (including drowsiness, confusion, convulsions, hallucinations, and in severe cases coma), respiratory depression, and bronchospasm.

Management
 - Airway protection 
 - Activated charcoal within 1 hour
 - IV Fluids
 
IV glucagon is the first-line management.
 
For symptomatic bradycardia, IV atropine may be used.

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2867
Calculation of infusion rate
Topic
66
Obstetrics & Gynaecology
- Dose of labetalol given at 20mg/hour: 20mg/hour x 0.5 hours = 10mg
- Dose of labetalol given at 40mg/hour: 40mg/hour x 0.5 hours = 20mg
- Dose of labetalol given at 80mg/hour: 80mg/hour x 0.25 hours = 20mg

Total dose of labetalol given: 10mg + 20mg + 20mg = 50mg
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QuestionQAAnswer
50
mg
A 37-year-old patient with hypertension in pregnancy is prescribed labetalol by intravenous infusion. She was initially given 20mg/hour, which was increased to 40mg/hour after 30 minutes, and then to 80mg/hour after another 30 minutes. This continued for 15 minutes, after which the response was satisfactory and the infusion was stopped.


What is the total dose of labetalol given?