Exam 1 Drugs - BZDs and Pre-Op Flashcards
At which pH is Midazolam water-soluble? Lipid-soluble?
Water-soluble pH < 3.5 - Open ring
Lipid-soluble pH > 4.0 - Closed ring
Midazolam (Versed):
pK
Peak
Elimination 1/2 Time
Vd
pK = 6.2
Peak: 20-30 mins (Peds), 5 minutes in adults
E 1/2 Time = 2 hours
Vd = 1-1.5 L/kg
Active metabolite of midazolam?
1-hydroxymidazolam
Midazolam sedation dose?
Peds: 0.25-0.5 mg/kg (Peaks in 20-30 mins)
Adults: 1-5 mg (Peaks in 5 mins)
Midazolam induction dose?
0.1-0.2 mg/kg over 30-60 seconds
Post-op Versed dose?
1-7 mg/hr
Concerns for prolonged midazolam administration?
T-cell suppression
Diazepam (Valium)
Onset
Peak
Elimination 1/2 Time
Vd
Onset: 1-5 mins
Peak: 1 hour (Adults), 15-30 mins (Peds)
Elimination 1/2 Time: 20-40 hours
Valium active metabolites?
Desmethyldiazepam (lasts 48-96 hours) and oxazepam
Diazepam (Valium) doses for…
Induction?
Seizures?
Induction = 0.5-1 mg/kg
Seizure = 0.1 mg/kg
Why does valium burn upon injection?
It contains propylene glycol
Lorazepam (Ativan)
Peak
Elimination 1/2 Time
Duration
Post-Op Dose
Peak: 20-30 minutes
E 1/2 Time: 14 hours
Duration: 6-10 hours
Dose: 1-4 mg
List benzodiazepine duration of action from shortest to longest…
Versed < Diazepam < Lorazepam
Romazicon (Flumazenil) is derived from…
1,4 imidazobenzodiazepine
Romazicon (Flumazenil) dosage to reverse sedation? Complete reversal?
0.3-0.6 mg
Complete reversal = 0.5-1 mg
Romazicon (Flumazenil) onset? Duration?
Onset = 2 mins
Duration = 30-60 mins
Diphenhydramine (Benadryl):
Class
Receptor
E 1/2 Time
Onset
Dose
Class: H1 Antagonists
Receptor: Vestibular
E 1/2 Time: 7-12 hours
Dose: 25-50 mg
Diphenhydramine inhibits what reflex?
Oculo-Emetic Reflex
Promethazine (Phenergan)
Class
Receptor
E 1/2 Time
Onset
Dose
Class: H1 Antagonsist
Receptor: Vestibular
E 1/2 Time: 9-16 hrs
Onset: 5 minutes
Dose: 12.5-25 mg
What is the most common bacterial infection associated with long-term H2 antagonist use?
Candida Albicans
What is the dose for the H2 antagonist Cimetidine (Tagamet)?
150-300 mg (1/2 for renal impairment)
What is the dose for the H2 antagonist Ranitidine (Zantac)?
50 mg diluted in 20 cc over 2 mins
1/2 dose for renal impairment
What is the dose for the H2 antagonist Famotidine (Pepcid)? Half-time?
20 mg - 1/2 dose for renal impairment
1/2 Time = 2.5-4 hours
What electrolyte should be monitored in a patient taking Pepcid?
Phosphorus
PPIs _________ Warfarin metabolism
Inhibit
PPIs block the enzyme that activate……
Plavix (Clopidogrel) - It doesn’t work as well
Omeprazole (Prilosec)
Dose:
How long before surgery do you administer?
40 mg dilated in 100cc NS over 30 mins
> 3 hours prior to surgery
Pantoprazole (Protonix)
Dose
Onset?
40 mg diluted in 100 cc NS over 2-15 mins
Onset - 1 hr
PPIs decrease ____________ and increase ____________
Gastric volume
pH
Particulate antacids are aluminum and magnesium based - Aspirating this is just as bad as aspirating…
Stomach acid
Non-particulate antacids neutralize acids and consist of…
Sodium, Carbonate, CItrate
Bicarb based
Sodium Citrate (Bicitra)
Onset
Duration
Dose
Onset - Immediate
Duration - 30-60 mins
Dose - 15-30 mL
Metoclopramide (Reglan) is FDA approved for…
Diabetic gastroparesis
Metoclopramide (Reglan) slows the metabolism of what?
Succinylcholine - Decreases plasma cholinesterase
Metoclopramide (Reglan)
Dose
When do administer?
10-20 mg over 3-5 mins
Give 15-30 prior to induction
What was the initial use for Droperidol?
Schizophrenia, psychosis
Droperidol dose?
0.625-1.25 mg
Ondansetron (Zofran)
Receptor
Dose
E 1/2 time
5-HT3
Dose - 4-8 mg
E 1/2 Time - 4 hours
Dexamethasone (Decadron)
Onset
Dose
Duration
When do you administer this?
Onset: 2 hours
Dose: 4-8 mg; Give more (12-20 mg) for airway trauma
Duration: 24 hours
Administer at start of case or 2 hours before the end of a long case
Scopolamine Patch
Class
E 1/2 Time
Onset
Peak
Dose
Class: Anticholinergic, Musarinic antagonist
E 1/2 Time: 24-72hours
Onset: 4 hours
Peak: 8-24 hours
Dose: The priming dose is 140 mcg, then over the next 72 hours 1.5 mg is absorbed through the skin
