PHARM - Sleep & MS drugs Flashcards
what is the role of the ventrolateral preoptic nucleus (VLPO) in sleep induction?
sleep promotion
- throughout the day, ATP is broken down to adenosine
- accumulating adenosine binds to A1 & A1 receptor on VLPO, a thalamic nucleus
- in resopnse, the VLPO releases GABA & galanin (inhibitory NTs)
- GABA opens Cl- channels, hyperpolarizing the membrane
- APs are mitigated -> sleep induction
what is the role of the lateral nucleus in sleep?
alertness
- lateral nucleus of hypothalamus releases orexin
- orexin projects to arousal regions of the brain:
- locus coerelulus
- tuberomamillary nucleus
what is the role of histaminergic neurons in sleep?
promote alertness
project to tuberomamillary nucleus, an arousal center
list the roles of GABA, melatonin, orexin, histamine in modulating sleep
- GABA - promote sleep
- melatonin - promote sleep
- orexin - promote arousal
- histamine - promote arousal
what are the four classes of hyponotic drugs?
- benzodiazepine-like drugs (GABA enhancers) - induce sleep
- melatonin agonists - induce sleep
- orexin antagonists - block arousal
- histamine 1 receptor antagonists - blcck arousal
what are the two classes of benzodiazepines?
list the drug names, clinical use, and MOA of the drugs belonging to each class.
both classes work by enhancing the affects of GABA.
- benzodiazepine like drugs (BLZs)
- include: zolpidem, zaleplon, eszopiclone
- clinical use: for hypnosis
- MOA: bind selectively alpha-1 subunit containing GABAA receptors
- benzodiazepines
- include: triazolam, - pams
- clinical use: for anxiolysis > hyponosis, anesthesia, muscle relaxation
- MOA: bind less selectively to alpha-1,2,3,5 containing GABAA receptors
describe the structure of GABAA receptors.
why is this clinically relevant?
- all made of 5 subunits: 2 alpha, 2 beta, 1 gamma
- the specific structure of the a-subunit can vary: a1, a2, a,3, a5
- BLZs (hypnotics):
- specifically bind a1 containg receptors
- benzodiazepines (anxiolytics):
- less specifically bind a1-a5 containing receptors
- BLZs (hypnotics):
- the specific structure of the a-subunit can vary: a1, a2, a,3, a5
benzodiazepine like drugs
- includes what drugs?
- clinical use
- MOA
- AE / CI / drug-drug interactions
- drugs: zolpidem, zaleplon, eszolpiclone
- clinical use: for hypnosis
- MOA: bind to alpha-1 containing GABAA receptors & enhance their affinity for GABA
- PK: metabolized by CYP-3A4
- AE / CI / drug-drug interactions:
- AE: drowsiness / insomnolence
- CI: in pt on CNS depressants - opiods, barbituates, ethanol
- drug-drug interactions:
- CYP-3A4 inhibitors: cimetidine, corbistat, ritonavir
- CYP-3A4 inducers: rifampin
- Flumenzenil
BZ-like drugs should be used with caution with patients taking what other drugs?
zolpedem, azleplon, escopiclone
- CYP-3A4 inhibitors (increase half life)
- cimetidine
- cobiscistat
- ritonavir
- CYP-3A4 inducers (decrease half life): rifampin
- competitive antagonists: flumazenil
administration of BZ-like drugs with which other drugs will limit their ability to induce sleep?
why?
zolpidem, zaleplon, eszopiclone
- rifapmin: induces CYP-450, which metabolizes BZ-like drugs
- flumazenil: a competitive antagonist at the BZ-like drug binding site
BZ-like drugs are absolutely contraindicated in patients taking what other drugs?
zolpidem, zaleplon, escopiclone
- CNS depressants:
- opiates
- ethanol
- barbiturates
what is flumazenil?
a competitive antagonist for BZ-like drugs
zolpidem is what kind of drug?
BZ-like drug
zaleplon is what kind of drug?
BZ like drug
eszopiclone is what kind of drug?
BZ-like drug
which BZ-like drug is most likely to cause rebound insonmia?
how does this rebound insomnia present?
zolpidem
insomnia the 1st night after discontinuation after chronic usage
suforexant
- clinical use
- MOA
- AE/CI
- clinical use: hypnotic
- MOA: orexin antagonist -> inhibits arousal
- AE/CI
- AE: CNS depressant [Schedule IV]
- CI: other CNS depressants
H1 receptor antagonists
- includes what drugs
- clinical use
- MOA
- AE/CI
- includes: doxepin, diphenhydramine
- clinical use: for hypnosis
- MOA: histamine antagonists - prevent arousal
- AE/CI:
- AE
- CNS depression - dopexin worse
- anti-cholinergic affects - diphenhydramine worse*
- CI: other CNS depressants
- AE
doxepin
- clinical use
- MOA
- AE/CI
- clinical use: for hypnosis
- MOA: histamine antagonists - prevent arousal
- AE/CI:
- AE: CNS depression > anti-cholinergic affects
- CI: other CNS depressants
diphenhydramine
- clinical use
- MOA
- AE/CI
- clinical use: for hypnosis
- MOA: histamine antagonists - prevent arousal
- AE: anti-cholinergic affects > CNS depression
- dry mouth
- constipation
- urinary retention
- blurred vision
*remember that in the treatment of headaches, diphenhydramine can be used to reverse akinesa caused by anti-emetics
ramelteon
- clinical use
- MOA
- AE
- clinical use: for hypnosis - weak drug
- MOA: agonist at melatonin receptors - MT1 & MT2
- AEs: posssible inc in serum prolactin
what is an advantage of ramelteon over other hypnotic agents?
has little abuse potential
loss of orexin neurons leads to what major pathologies?
- narcolspey: loss of sharp wake to sleep transitions
- cataplexy: sudden loss of motor function
what drugs are used to treat narcolepsy?
- - dafinil: modafinil, armodafinil
- sodium oxybate (xyrem)
what drugs are used to treat cataplexy?
- venlafaxine
- sodium oxybate (Xyrem)
modafinil
- clinical use
- MOA
- AE
- clinical use: narcolspey
- MOA: unknown
- AEs:
- headaches
- nausea / chills / back pain
armodafinil
- clinical use
- MOA
- AE
- clinical use: narcolspey
- MOA: unknown
- AEs:
- headaches
- nausea / chills / back pain
sodium oxybate
- clinical use:
- narcolepsy
- cataplexy
- MOA: unknown
- AE/CI:
- respiratory depressant
- CNS depressant
sodium oxybate is contraindicated in patient taking what other drugs?
CNS depressants AND respiratory depressants
venlafaxine
- clinical use
- MOA
- AE/CI
- clinical use: cataplexy
- MOA: SNRI - increases daytime arousal
- AE/CI: minor GI effects
the drugs used to treat multiple sclerosis (MS) fall belong to what major classes?
what is the therapuetic goal is each class?
- glucocorticoids: for acute attacks - initial episode or relapses
- immunosuppressive biologics: disease modifying
- relapsing remitting
- secondary progressive
- primary progressive
what is an AE of all drugs used to treat MS?
why?
increased infection risk
they are all immunosuppresive.
INF-B
- what kind of drug
- clinical use
- MOA
- AE
- MS disease modifying drug
- clinical use: relapsing-remitting AND secondary progressive MS
- MOA: possibly T-cell proliferation
- AE
- fever
- chills
- myalgia
glatiramer acetate
- what kind of drug
- clinical use
- MOA
- AE
- disease modifying MS drug
- clinical use: relapsing remitting MS - also, is pregnancy class B
- MOA: unknown, T-cell related
- AE: n/a
natalizumab
- clinical use
- MOA
- AE
- disease modifying MS drug
- clinical use: relapsing remitting MS
- MOA: inhibits alpha-4 integrins (VCAM-1 receptors), inhibiting vascular adhesion
- AE: increases risk multifocal leukoencephalopathy (PML), a fatal, progressive disaese caused by JK virus
what must patient be tested for prior to being described natalizumab?
- antibodies against JC virus, which can cause polymultifocal leukoencephalopathy (PML)
- natalizumab increases risk of PML developing from JC virus
fingolimod
- clinical use
- MOA
- AE/CI
- disease modifying MS tx
- clinical use: relapsing - remitting MS
- MOA: binds to sphinosin-1-phosphate (S-1-P) receptors, preventing lymphocytes from entering circulatation
-
AE:
- herpes simplex / herpes zoster
- retinal edema
- cardiac conduction block
alemtuzumab
- what kind of drug
- clinical use
- MOA
- AE/CI
- disease modifying MS tx
- clinical use: relatpsing remitting MS
- MOA: monoclonal antibody against CD52
- AE/CI:
- Thyroid-associated AEs
- Thryoid papillary carcinoma
- Thrombocytopenia
- myelosuppresion
ocrelizumab
- what kind of drug
- clinical use
- MOA
- AE/CI
- disease modifying MS drug
- clinical use: relapsing remitting AND primary progressive multiple sclerosis
- MOA: antibody against CD-20 marker on mature B-cells -> depletes mature B-cells
- AE:
- infusion rx
- Hep-B reactivation
which disease modifying MS drug can be used to treat secondary progressive MS?
INF-B
which disease modyfing MS drug can be used to treat primary progressive MS?
ocrelizumab