University:
University of North Carolina at Chapel Hill
Course:
NURS 312 | Pharmacology
Academic year:

2020
Views:

140

Pages:

1
Author:

Alexa Livingston

1.2 – “Catchi “Catching ng some Zs”: N Non on-be -benzo nzo hypnotics, melatonin, rame ramelteon lteon • Pharmacotherapy for insomnia should be limited to short term management Nonbenzodiazepine hypnotics • Include zolpidem, zaleplon, eszopiclone (“ZZZ mattresses) • MOA: allosterically bind GABA-A receptor at the same site as benzos (lady & Ben’s Diner customary grabbing Cab-A door at once). more targeted action than BZDs. Potentiate GABA A transmission throughout the CNS (special delivery of pam-cakes increasing cab driver effects). o Major inhibitory CNS neurotransmitter (along with glycine) (CNS & “take it easy” signs on cab). o Activated GABA-A receptor is a chloride channel (Chlo-rider cap). ↑chloride conductance inhibits synaptic transmission → CNS depression (CNS light on cab). Increased permeability hyperpolarizes & stabilizes membrane potential, making less excitable. o Chloride channel conductance is d/t an increase in frequency of opening rather than increased duration (“Now Open More Frequently”) o Different site altogether from alcohol & barbiturates (drinking man & barber shop around cab outside) • As a consequence of more specific activity, have decreased anxiolytic and anti-seizure activity compared to benzos • Rapid onset & short duration of action (“Fall asleep FAST”; sheep jump and fall) • Rapidly metabolized by the liver. Serum half-life is 1-2 hours, so residual effects (e.g. next morning drowsiness) rare. o Zaleplon & zolpidem treat sleep onset insomnia (“Fall asleep”) o Eszopiclone has the longest half-life & is effective for both sleep onset & sleep maintenance insomnia. • Adverse effects: o Similar to those associated with benzos with lower frequency and severity. o Less likely to cause tolerance than benzos (“Returns not tolerated”). Ergo less addiction, dependence, reliance. o Elderly are more sensitive to effects including excessive sedation, delirium, night wandering, cognitive impairment, aggravation. o Can cause central ataxia. ▪ ↑ fall risk in the elderly. Included in BEERS criteria. (Falling stack of pillows in front of older man) o Do not combine with other CNS depressants (“Do not combine with coupons” sale sign; bee swatter) Ramelteon & tasimelteon • Melatonin receptor agonists. o MT1 & MT2 receptors located above the suprachiasmatic nucleus of the hypothalamus (fan nucleus above the X-shaped blades; X for optic chiasm, ergo suprachiasmatic nucleus) • Involved in circadian rhythms involved in maintaining sleep/wake cycle (lights on and off) • Few adverse effects. No rebound insomnia or significant withdrawal symptoms • Demonstrated safety profile in geriatric patients; one of the few with no dose adjustment needed in geriatrics. (Old man falling asleep) Flumazenil (fluffy muzzled dog) • Competitive antagonist at the BZD receptor (dog is antagonizing man on sidewalk). • Used for reversal of non-benzo induced sedation.