Benzodiazepines

Question 1

onset times of midaz

Answer 1

po 0.5-0.75 mg/kg 10-30 min
nasal 0.1-0.3 mg/kg 10 min
rectal 0.3-0.5 mg/kg 20-30 min
iv 0.05-0.1 mg/kg
-IM has greater bioavailability than intranasal

Question 2

action of midaz

Answer 2

• sedative-hypnotic
• anxiolytic
• amnestic
• anticonvulsant
• skeletal muscle relaxant

Question 3

Midaz:

Answer 3

• water soluble, lower incidence of phlebitis, thrombosis, injection pain
• inactive metabolites

Question 4

diazepam

Answer 4

• tranquilizer, muscle relaxant, anticonvulsant
• lipid-soluble and protein-bound
• antegrade amnesia, poor retrograde amnesia
• crosses placenta

Question 5

diazepam: elimination

Answer 5

• first pass thru liver
• elimination impaired with cimetidine admin
• inc duration in liver disease and elderly

Question 6

diazepam: active metabolites

Answer 6

-active metabolites–secondary peak–effects 6-8 hours after admin

Question 7

diazepam: CO2 response

Answer 7

-CO2 curve is shifted down, but NOT to right

Question 8

etominade and adrenal suppression

Answer 8

• inhibits conversion of cholesterol to cortisol
• usu repeated, prolonged admin
• not for burn pt debridement
• also riskier in pts who are stressed–sepsis, hemorrhage, burn injury

Question 9

flumazenil

Answer 9

-benzo receptor antagonist at CNS
-0.1-0.2 mg produces partial antagonsm
1 mg-complete antagonism
-higly extracted first pass thru liver

Question 10

contraindications

Answer 10

• pts on benzos to control life-threatening inc ICP or status epilepticus
• withdrawing from cyclic antidepressants
• twitching, rigid, wide QRS

Question 11

Flumazenil in pts dependent on antagonism

Answer 11

-takes 6-10 mins to reach full effect–start 0.1-0.2 mg, up to 1-3 mg slowly

Question 12

flumazenil: monitoring

Answer 12

• can wear off before long-acting benzo

- convulsions are most serious side effects–manage w/ benzos, barbiturates, phenytoin