Benzodiazepines Flashcards
Diazepem (Valium)
1) Indications
2) Onset, DOA, Vd, & Half life
3) Metabolism
1) Used for pre op pediatric sedation and spinal level skeletal muscle spasms and pain
2) Onset: rapid DOA 6-8hrs 98% Pb Vd 1L/kg E1/2t = 20-50hrs
3) CYP450 microsomal enzymes conjugation and hydroxylation. 3 metabolites. 1 active metabolite via demethylation = desmethydiazepam = half life of 48-96hrs = hangover effect. Metabolites excreted in the urine
Diazepem (Valium): Action
“Benzodiazepine - increases the affinity for GABA at GABA receptors. GABA is the major inhibitor neuron of the CNS. The binding of GABA to the receptor causes the opening of the Cl- channel allowing influx into the cell. Because the channel remains open, this hyperpolarizes the post synaptic membrane. This creates anterograde amnesia, sedation, and anxylosis.”
Diazepem (Valium) : Adverse Effects
“decreased CBF, CMRO2, decreased EEG, does not attenuate response to DVL,
paradoxical excitement
Diazepem (Valium)
1) Contraindications
2) Additional Info
3) Dosage
1) "Hypersensitivity Pregnancy Glaucoma Reduce dose in eldery Caution in hypoalbuminemia in hepatic or renal disease Severe hypotension"
2) “Most highly protein bound
Hang over effect
Reverses with FLUMAZENIL”
3) “0.5-1 mg/kg IV induction
Premedication 0.2 mg/kg IV
PO 10-15mg Premedication
Anticonvulsant 0.1 mg/kg IV
Midazolam-Versed: Action
Imadazole Ring (supplied as open ring in low pH = water soluble, when placed in pH 7.4, ring closes and become very lipid soluble = fast onset).
Benzodiazepine - increases the affinity for GABA at GABA receptors. GABA is the major inhibitor neuron of the CNS. The binding of GABA to the receptor causes the opening of the Cl- channel allowing influx into the cell. Because the channel remains open, this hyperpolarizes the post synaptic membrane. This creates anterograde amnesia, sedation, and anxylosis.
Midazolam-versed
1) Indications
2) Onset, DOA, Vd, Half Life
3) Metabolism
1) Use pre op for anxiolysis, used as anticonvulsant, and spinal level skeletal muscle relaxation.
2) Onset: 30-60sec (1-5min effect site redistribution – redose at 5mins) DOA: 30-90mins 94% protein bound Vd 1.5L/kg E 1/2t = 1-4 hrs
3) CYP450 microsomal enzymes conjugation/hydroxylation – urinary excretion
Midazolam-Versed: Adverse Effects
“decreased CBF, CMRO2, decreased EEG, does not attenuate response to DVL,
paradoxical excitement
Midazolam-Versed
1) Contraindications
2) Additional Info
3) Dosage
1) "Hypersensitivity Pregnancy glaucoma Reduce dose in elderly Caution with hypoalbuminemia in hepatic or renal pts Severe hypotension"
2) “Additive effect with opioids.
Reversed with FLUMAZENIL
No hangover effect
Great for beir blocks – if local anesthetic toxicity – already have benzo on board.”
3) 0.5 mg/kg PO peds
1-2.5 mg IV up to 5 mg
Induction 0.1-0.2 mg/kg over 30-60 secs
Lorazepam-Ativan: Action
“Benzodiazepine - increases the affinity for GABA at GABA receptors. GABA is the major inhibitor neuron of the CNS. The binding of GABA to the receptor causes the opening of the Cl- channel allowing influx into the cell. Because the channel remains open, this hyperpolarizes the post synaptic membrane. This creates anterograde amnesia, sedation, and anxylosis.”
Lorazepam-Ativan
1) Indications
2) Onset, DOA, Vd, & Half life
3) Metabolism
1) “Most potent sedative and amnestic.
Used for acute seizure treatment”
2) Onset rapid 1-2mins DOA 10-20 hrs 80% PB Vd 1L/kg E1/2t = 10-20hr
3) Cyp450 microsomal enzymes – conjugated to be eliminated in urine.
Lorazepam- Ativan: Adverse Effects
“PAIN ON INJECTION – thrombophlebitis
Plt aggregation inhibition with long term use.
decreased CBF, CMRO2, decreased EEG, does not attenuate response to DVL,
paradoxical excitement
Lorazepam- Ativan
1) Contraindications
2) Additional Info
3) Dosage
1) "Hypersensitivity Pregnancy Glaucoma Reduce dose in elderly Caution with hypoalbuminemai in hepatic or renal pts Severe hypotension"
2) “Additive effect with opioid
Reversed with FLUMAZENIL
No hangover”
3) 50mcg/kg (1-4mg)
