Flashcards in Midazolam Deck (32)
What is the trade name of Midazolam?
What is the drug classification of Midazolam?
What are the effects of Midazolam?
Skeletal muscle relaxation effects
What are the clinical uses of Midazolam?
-used in preop medication and conscious sedation
-induction and maintenance of anesthesia
-office based anesthesia settings
-unlabeled/investigational use for anxiety and status epilepticus
What is the MOA of Midazolam?
-produces effects by facilitating the action of GABA, which is the principle inhibitory neurotransmitter of the CNS
-does not activate the receptor but instead enhances the affinity of the GABA receptor for GABAa
-this causes enhanced opening of chloride channels which hyperpolarizes the postsynaptic cell membrane, rendering it more resistant to excitation
How is Midazolam metabolized? What are the metabolites?
-rapidly metabolized by Hepatic CYP450 enzymes to active and inactive metabolites
What is the principle metabolite of Midazolam? How potent is it? How is it eliminated?
1-hydroxymidazolam, which has 1/2 the activity of midazolam
-it is conjugated to 1-hydroxymidazolam glucuronide and cleared by the kidneys
Does renal failure alter Midazolam?
E 1/2 time, Vd, and clearance are NOT altered by renal failure
Is Midazolam lipid soluble or water soluble in the body? What does this mean?
HIGHLY lipid soluble with rapid redistribution from to inactive tissues
What is the onset of action of Midazolam?
What is the time to Peak of Midazolam?
3- 5 minutes
What is the IV DOA of Midazolam? IM?
15 - 80 minutes IV
up to 6 hours IM
What is the E 1/2 time of Midazolam? What would prolong this?
1 - 4 hours (Dr. E says 1 - 6.5hrs)
prolonged in: elderly, cirrhosis, CHF, obesity
What is the Vd of Midazolam?
1 - 1.5 L/ kg
Is Midazolam protein bound?
94% protein bound!
What are the CNS effects of Midazolam?
-Paradoxical excitement...EH not really/ RARE
-Decreases CBF and CMRO2
-Does NOT produce isoelectric EEG
-Preserves cerebrovascular response to CO2
-Does NOT attenuate ICP response to laryngoscopy
-Potent Anticonvulsant and Amnestic!!!!!!!
What are the respiratory effects of Midazolam?
-Produces dose dependent decrease in Ventilation
-Hypoxemia and hypoventilation enhanced in presence of opioid
-Depresses reflex deglutition (swallowing)
-CO2 response curve FLATTENS- does NOT shift
-transient apnea may occur after large doses
What are the CV effects of Midazolam?
-Decreases SVR at induction dosage, BP subsequently decreases
-does NOT attenuate SNS response to laryngoscopy
What are the contraindications to the use of Midazolam?
-Narrow angle glaucoma
What drugs slow the metabolism of Midazolam?
-drugs that inhibit CYP450!!!!
What drugs enhance the metabolism of Midazolam?
-drugs that induce CYP450
What drug inhibits hepatic clearance of Midazolam?
Fentanyl inhibits hepatic clearance of midazolam when administered during GA
What is the Premedication/ Sedation dosage of Midazolam IV?
0.04 - 0.08 mg/kg IV/IM OR
0.5 - 5 mg IV/IM carefully titrated
(Dr E says 1 - 2.5 mg IV, can give as high as 5mg, as needed)
What is the Induction dose of Midazolam?
0.05 - 0.35 mg/kg IV (Dr. E says 0.1 - 0.2 mg/kg over 30 - 60 sec)
What is the maintenance dose of Midazolam?
0.05 mg/kg PRN of 1 mcg/kg/min infusion
What should you decrease the dosage by if narcotics or other CNS depressants are used?
IS Midazolam water-soluble or lipid soluble in solution?
WATER-SOLUBLE- available in an acidified solution which produces minimal irritation after IM or IV injection
What is the competitive antagonist of Midazolam?
What is the pregnancy category of Midazolam?