Central Nervous System Stimulants and Depressants
By: Amanda Gidaszewski, Karina Del Toro, Samantha Ruiz, Amanda Hilliard



Stimulants

- Drugs that stimulate a specific part of the brain or spinal cord.
- Sympathomimetic agents
- Stimulate fight of flight

- organs_cns.jpg

Uses:

-ADHD:
Cannot maintain attention span. Hyperactivity and impulsivity. May have a genetic predisposition.
-Narcolepsy:
Person unexpectedly falls asleep in the middle of normal day activities.
-Migraine HA:
Severe pain felt on one or both sides of the head. May have N/V, increased sensitivity to light and sound.
-Analeptics:
Reversal of anesthesia-induced respiratory depression
-Anorexiants:
May suppress the appetite control center of the brain.

S/E:

Wide-range, dose related
Speed up body systems
-palpitations, tachycardia, hypertension, angina, dysrhythmias, insomnia, increase urine frequency, N/V/D, restlessness, nervousness, anxiety

Stimulants

-Analeptics: Highly toxic and abuse potential

*Caffeine (No-Doz, Vivarin)- found in OTC & combo Rx drugs n foods. Caution in pt w/ Peptic ulcer, MI, dysrhythmias.
*Doxapram (Dopram)- treats respiratory depression associated with overdose of CNS depressants.

-Anorexiants: appetite suppressants

*Orlistat (Xenical)- alters fat metabolism
*Sibutramine (Meridia)- decreases appetite

-Amphetamines: stimulate the CNS, increase mental alertness

*Amphetamine (Adderall)- treatment of ADHD, narcolepsy, and obesity
*Methylphenidate (Concerta, Ritalin)- for ADHD and narcolepsy

adderall.jpg

-Serotonin Agonists

*Sumatriptan (Imitrex)- Acute treatment of migraines. Should not be given to pt w/ CAD!
*Sibutramine (Meridia)- for weight loss, inhibits the reuptake of norepinephrine and serotonin



Nursing Implications

-Look for contraindications, interactions.
-Cardiac abnormalities, seizure, liver problems.
-Height and weight of children.
-Methylphenidate (Concerta, Ritalin) should be given at least 6 hours before bedtime to reduce insomnia, and 45 minutes before meals.
-Orlistat (Xenical) should be taken with meals that contain fat.
-Sumatriptan (Imitrex), Sibutramine (Meridia) should avoid foods containing tyramine.



Depressants

-Sedatives
-Hypnotics
-Sedative Hypnotics-dose dependent

*Sedatives

Drugs that have inhibitory effect on CNS to reduce nervousness, exictability, and irritability w/out causing sleep. Can become hypnotic if given in large enough doses.

*Hypnotics

Calm or soothe CNS to cause sleep.

*Sedative hypnotics

Act as sedative or hypnotic, low doses calm CNS w/out causing sleep, high doses calm to the point of causing sleep.

Sleep
-Cyclic & repetitive
REM- REM Rebound: from prolonged use of sedative-hypnotics. Reduce amt of REM Sleep results in daytime fatigue.
NREM- 4stages

Sedative-Hypnotics Barbituates

-Have low therapeutic index. Very habit forming.

Four Categories
1. Ultrashort: onset <15 mins, duration 2-4 hrs.
-Mephobexital, thiamylal, thiopental
2. Short: onset 15-20 mins, duration 2-4 hrs.
-Pentobarbital, secobarbital
3. Intermediate: onset 20-30 mins, duration 2-4 hrs.
-Butabarbital
4. Long: onset 30-60, duration 6-8 hrs.
-Phenobarbital, mephobarbital

Drug Effects
Low doses- sedative
High doses- hypnotic
Enzyme-inducers- stimulate liver enzymes, causing breakdown of many drugs. (shortens duration of action for many drugs)

Uses:
-induce sleep
-reduce nervousness, irritability, w/out causing sleep
-anticonvulsant
-anesthesia for surgical procedure

Most common
Pentobarbital (Nembutol)-reduces anxiety before surgery
Phenobarbital (Luminal)-prevents seizures
Secobarbital (Seconal)-hypnotic to induce sleep


Contraindications
Drug allergy, pregnancy, respiratory difficulty, liver disease, used w/ alcohol, opioids, benzodiazepines, and other additive CNS depression agents.

S/E
Drowsiness, lethargy, coma, respiratory depression, bronchospasms, N/V/D, constipation, agranulocytosis, hypertension

Toxicity & overdose
-Leads to respiratory arrest.
sleep-coma-death
Treatment: maintain airway and support respiration. NO ANTAGONIST EXISTS
Drug Reactions:
Alcohol, antihistamines, benzodiazepines, narcotics, tranquilizers, MAOIs.


Benzodiazepines (sedative-hypnotics)

*most commonly prescribed drug classes, favorable S/E profiles.

-Don't suppress REM sleep
-Don't induce microsomal enzyme activity

Uses:
-Sedation
-Sleep induction
-Skeletal muscle relaxation
-Anxiety relief
-Treatment of alcohol withdrawl
-Agitation
-Depression
-Epilepsy
-Balanced anesthesia

Drug effects:
Calm of CNS, controll agitation and anxiety, reduce sensory stimulation, skeletal muscle relaxation.

Mechanism of Action:
Depress CNS activity, affect hypothalamic, thalamic, and limbic systems of brain
-don't suppress REM sleep, so have less HANGOVER EFFECT!
-don't increase metabolism of other drugs

Drugs:
*Flurazepam (Dalmane)- long-acting hypnotic used for short-term therapy of insomnia
*Temazepam (Restoril)- short-term treatment of insomnia. Don't use in pt w/ narrow angle glaucoma.
*Triazolam (Halcion)- short-term treatment of insomnia.

S/E
-Headache, drowsiness, dizziness, vertigo, lethargy, paradoxical excitement (nervousness), HANGOVER EFFECT! :D

Overdose
Somnolence, confusion, coma, diminished reflexes

Muscle relaxants

-Relieve pain related to skeletal muscle spasms. Majority are central acting, and direct acting. Closely resembles GABA.

Drugs
*Dantrolene (Dantrium)- malignant hyperthermia
*Baclofen (Lioresal)
*Cyclobenzaprine (Flexeril)

*Metaxalone (Skelaxin)

Uses:
relief of painful musculoskeletal conditions, muscle spasms, MS, cerebral palsy. Works best with physical therapy.

S/E
Euphoria, lightheadedness, dizziness, drowsiness, fatigue, muscle weakness, risk for falls!

Nursing Implications:

-Check for allergies, medical history, and medications.
-Baseline vitals and I&O
-Take 15-30 minutes before bedtime
-May cause REM rebound, a tired feeling the next day. Careful with elderly (fall risks)
-Avoid alcohol and other CNS depressants
-May take up to 2-3 weeks to see improvement in sleep with barbiturates.
-SAFETY: side rails up, bed alarms, no smoking, assist with ambulation, keep call light within reach.

´╗┐Follow the link below to review and test your knowledge...

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Lane, L, Collins, S, Harrington, S, Rainforth, S, & S., J. (2010). Pharmacology and the Nursing Process. Mosby Inc.

Petges, Nancy. RN MSN. Pharmacology: Central Nervous System Stimulants and Depressants Powerpoint, 2011.