Neurology Rx


Seizure Rx

Properties of Commonly Used Anticonvulsant Drugs
Drug Oral Dose, Milligrams per Day Therapeutic Level, Micrograms per mL Days to Reach Steady State Serum Half-Life, Hours
Carbamazepine (Tegretol)
 
400-1200, divided 3 or 4 times a day 4-12 2-4 12-17
Felbamate (Felbatol)
 
1200-2400, divided 3 or 4 times a day 20-100 2-5 13-23
Gabapentin (Neurontin)
 
900-3600, TID 1-2 1-2 5-7
Lamotrigine (Lamictal)
 
25-500, BID 2-5 6-10 25-33
Levetiracetam (Keppra)
 
1000-3000, BID 5-45 1-2 6-13
Oxcarbazepine (Trileptal)
 
600-1200, BID 10-30 1-3 9
Phenytoin (Dilantin)
 
300-600, TID 10-20 2-10 7-42
Topiramate (Topamax)
 
200-400, BID 2-5 4-8 21
Valproic acid (Depakene)
 
15-60 mg/kg, BID or TID 50-150 2-4 12-18

Benzodiazepines

Generic Name Time to Peak Effect
 
Elimin-ation Half-Life (h) Duration of Action Active Metabolite (half-life) Oral Dose Equivalent to Diazepam 10 mg PO
Short Acting
Alprazolam 1-2 h 6-12 4-7 h No 0.5
Midazolam IV 1-2 min 3-6 IV 2 h Yes 5
IM 10-15 min IM 4-6 h
PO 30-60 min PO 4-6 h
Oxazepam 20-30 min 5-10 3-6 h No 20
Tetrazepam 1-3 h 15 6-8 h No 50-100
Triazolam 15-30 min 2-5 6-7 h No 0.25-0.50
Intermediate Acting
Bromazepam 1-3 h 10-20 <12 h Yes 5-6
Cinolazepam 0.5-2.0 h 9 9 h No 40
Estazolam 1 h 10-24 <12 h No 1-2
Flunitrazepam 15-20 min 18-24 4-6 h Yes (36-200 h) 1
Loprazolam 0.5-4.0 h 6-12 <12 h No 1-2
Lorazepam IV 5-20 min 9-16 6-8 h No 1
IM 20-30 min
PO 30-60 min
Lormetazepam 0.5-2.0 h 10-12 <12 h No 1-2
Nimetazepam 15-30 min 14-30 <12 h No 5
Nitrazepam 0.5-5.0 h 16-48 <12 h No 10
Premazepam 2 h 10-13 <12 h No 3.75
Temazepam 80-100 min 9-12 5-20 h No 20
Long Acting
Chlordiazepoxide 2 h 5-30 5-30 h Yes (36-200 h) 25
Clonazepam 20-60 min 20-80 <12 h No 0.5
Clorazepate 1-2 h 48 8-24 h Yes (36-200 h) 15
Cloxazolam 2-5 h 65 18-50 h No 1-2
Diazepam IV 1-5 min 20-50 IV 15-60 min Yes (36-200 h) 10
PO 15-45 min PO 12-24 h
PR 5-45 min --
Flurazepam 30-60 min 2 12 h Yes (50-100 h) 15-30
Flutoprazepam 0.5-2.0 h 60-90 24 h Yes 2-3
Halazepam 1-3 h -- 12-24 h Yes (30-100 h) 20-40
Ketazolam 2.5-3.0 h 30-100 12-24 h Yes (36-200 h) 15-30
Medazepam -- 36-150 10-12 h Yes (36-200 h) 10
Nordazepam 2 h 40-50 12-14 h Yes (50-120 h) 10
Phenazepam 1.5-4.0 h 60 12 h Yes 1
Pinazepam 1-2 h 20-25 12-24 h Yes (40-100 h) 20
Prazepam 2-6 h 40-80 12-24 h Yes (36-200 h) 10-20
Quazepam 0.5-2.0 h 27-41 12-24 h Yes (28-80 h) 20
 

Non-Benzodiazepine Sedatives/Insomnia

 
Name Plasma Half-Life
Buspirone 2-3 h
Carisoprodol 100 min
Chloral hydrate 4 min for chloral hydrate and 6–10 h for trichloroethanol
Diphenhydramine 3.4-9 h
Doxepin 15 h
Eszopiclone
(Lunesta)
6 h
Gamma hydroxyl butyric acid 0.3-1 h
Hydroxyzine
(vistaril)
20-25 h
Melatonin 40–50 min
Meprobamate 6-7 h
Ramelteon 1-3 h
Remeron
(Mirtazapine)
 20-40 h
Trazodone 3-6 h
Zaleplon 0.9-1.2 h
Zolpidem
(ambien)
1.4-4.5 h
Zopiclone and eszopiclone 3.5-6.5 h

Selected Aspects of Nonbenzodiazepine Overdose:
Agent Features Commonly Seen with Overdose Unique Toxicologic Effects
Buspirone Sedation, GI distress, vomiting, hypotension, priapism & dizziness. Generalized seizures (rare)
Serotonin syndrome (possible)
Carisoprodol Sedation, coma, cardiovascular collapse, pulmonary edema, Myoclonic jerks
Meprobamate Sedation, coma, cardiopulmonary depression Gastric bezoar with prolonged coma
Chloral hydrate Coma Cardiac instability, ventricular arrhythmias, sensitivity to catecholamines, GI distress, hemorrhagic gastritis
β-Hydroxybutyrate Amnesia, sedation, seizure, coma, cardiac and respiratory depression Steep dose-response curve
Sudden awakening
Melatonin Sedation, headache, dizziness, fatigue,  disorientation None observed
Ramelteon Sedation None observed
Zolpidem Sedation,  vivid dreams, sleep-walking & driving, coma possible Limited experience, vomiting
Zaleplon Sedation, incoordination Limited experience, headache (possible)
Zopiclone and eszopiclone Sedation Limited experience, none observed

 

Opioids

  Oral Equianalgesic Dose to Morphine 10 mg SC (mg) Parenteral Equianalgesic Dose to Morphine 10 mg SC (mg) Duration of Action (hours) Elimination Half-Life (hours)
Opiate
Codeine 200 120 3-6 -
Morphine 30 10 3-6 2-3
Semisynthetic
Buprenorphine 4 SL 0.3 6-24 37
Hydrocodone 30 Not available 3-4 -
Hydromorphone 7.5 1.5 3-6 2-4
Oxycodone 20 Not available 4-6 -
Oxymorphone 6 1.5' 3-6 3-4
Synthetic
Diphenoxylate 2.5 Not available -  
Fentanyl 0.125 0.100 1-2 3-4
Meperidine 300 100 1-3 3-4
Methadone 20 10 6-8 21-25
Pentazocine 150 50 SC 3-4 2-4
Propoxyphene 130 Not available 4-6 6-12
Tramadol 100 100 9 5-7
 

Stroke

< 4.5 hr of symptom onset:
rt-PA is 0.9 mg/kg IV, Max: 90 mg. 10% of the dose is given as a bolus, with the remaining amount infused over 60 min
TIA pts:
Aspirin (325 mg PO)/Plavix (75mg po qd) plus dipyridamole (400 mg PO) is recommended.
Stroke pts:
Aspirin (325 mg PO) is recommended within 24-48 hrs
If BP control is needed, use a titratable IV antihypertensive, such as labetalol (typical starting dose is 10-20 mg over 1-2 min; continuous infusion dosage generally starts at 2 mg/min, titrated to effect) with a target MAP reduction of 10% to 25%.