neurological emergencies

Question 1

mannitol ; osmitrol

Answer 1

Classification: Osmotic diuretic

MOA: increases the osmotic pressure inhibiting reabsorption of water and electrolytes. Causes excretion of water, sodium, potassium chloride, calcium, phosphorus, magnesium, urea, and uric acid.

Pharmacokinetics: onset 15 min, duration varies; HL: 100 minutes

Indications: treat acute increased intracranial pressure due to cerebral edema or intraocular pressure

AR/SE: chills, headache, dizziness, mental status changes, chest pain, n/v

Contraindications: known allergy, pts with dehydration or known intracranial bleeding.

Dosage: 1.5-2 g/kg over 30-60 minutes

Question 2

diazepam ; valium

Answer 2

Classification: Benzodiazepine, anticonvulsant, sedative

MOA: depresses the CNS by potentiating GABA, an inhibitory neurotransmitter; produces skeletal muscle relaxation.

Pharmacokinetics: Onset: IV 1-5 minutes, duration IV 15-60 min

Indications: treat seizure activity including status epilepticus; can be used as skeletal muscle relaxant, acute anxiety, premedication before cardioversion

AR/SE: dizziness, drowsiness, hypotension, respiratory depression, amnesia, n/v

Contraindications: known allergy

Dosage: 5-10 mg IV may repeat q 5-10 min up to 30 mg total

Special Considerations: (P class D) may cause respiratory arrest if given too quickly or in excess. Do not mix with other drugs, may cause precipitate.

Question 3

lorazepam ; ativan

Answer 3

Classification: anticonvulsant, antianxiety, benzodiazepine, sedative

MOA: Depresses CNS by potentiating GABA
Pharmacokinetics: onset 1-5 minutes IV (15-30 min IM), duration 6-8 hours

Indications: decrease anxiety and seizure activity, status epilepticus, premedication before cardioversion.

AR/SE: Apnea and cardiac arrest (rapid IV), dizziness, drowsiness, lethargy, slurred speech, hypotension, blurred vision, N/V.

Contraindications: known allergy

Dosage: 0.5-2 mg IV/IO/IN, (1-4 mg IM) may be repeated if necessary but not to exceed 8 mg in 12 hrs.

Special considerations: (P Class D) Flush line before administration if other drugs have been given.

Question 4

midazolam ; versed

Answer 4

Classification: benzodiazepine, antianxiety, sedative/hypnotic, anticonvulsant

MOA: Acts on CNS to produce generalized CNS depression via GABA

Pharmacokinetics: Onset IN 5 min, IM 15 min, IV 3-5 min, Duration IN ½-1 hr, IM/IV 2-6 hrs

Indications: seizure activity, anxiety, premedication before painful procedures

AR/SE: Apnea, laryngospasm, respiratory depression, cardiac arrest, phlebitis, hiccups

Contraindications: known allergy, preexisting CNS depression, uncontrolled severe pain or
angle-closure glaucoma.

Dosage: 1-2.5mg IV, 5mg IN (for sedation/induction, initial dose of 2-4 mg IV/IO followed by 3-5 mg q 15 min to maintain sedation)

Special considerations: (P Class D) monitor vital signs continuously.

Question 5

phenytoin ; dilantin

Answer 5

Classification: anticonvulsant

MOA: limits seizure activity by altering ion transmission; may also decrease synaptic transmission.

Pharmacokinetics: onset 3-5 min; duration varies

Indications: treatment and prevention of grand mal and partial complex seizures, status epilepticus, and arrhythmias caused by digitalis toxicity.

AR/SE: Suicidal thoughts, drowsiness,dizziness hypotension, diplopia, nystagmus , arrhythmias, rash, itching, n/v

Contraindications: known allergy, pts with alcohol intolerance, pts with sinus bradycardia or high degree AV blocks

Dosage: 10-20 mg/kg IV loading dose at a rate between 25-50 mg/min

Special Considerations: (P class D) Precipitates with D5W

Question 6

phenobarbital ; luminal

Answer 6

Classification: anticonvulsant, barbiturate

MOA: produces CNS depression, decreased motor activity and alters cerebellar function; inhibits transmission in the nervous system and raises the seizure threshold.

Pharmacokinetics: onset 5-15 minutes; duration 4-6 hrs

Indications: used as anticonvulsant in grand mal, partial, and febrile seizures, status epilepticus, and acute anxiety.

AR/SE: drowsiness, AMS, agitation, hypoventilation, apnea, bradycardia, hypotension, syncope, headache, N/V

Contraindications: known allergy to barbiturates

Dosage: 100-250 mg/kg slow IV for status epilepticus