DRUGS and PHARMACOLOGY Flashcards
1
Q
Steroids
A
- Prednisone
- Duration of action : 12-36 hours
- Antiinflammatory activity : 4
- Equivalent dose : 5 mg
- Methylprednisolone
- Duration : 12-36 hours
- anti inflammatory activity : 5
- Equivalent dose : 4 mg
- Dexamethasone
- Duration : 36-54 hours
- Anti inflammatory activity : 25
- equivalent dose 0.75 mg
- Cortisol
- Duration : 8-12 hours
- Anti inflammatory activity : 1
- Equivalent dose 20 mg
2
Q
Phenobarbital
A
- Gaba receptor mediated chloride channel opening
- CYP metabolism
- 1-5 mg /kg /day
- sedation, mood changes
3
Q
Phenytoin and fosphenytoin
A
- sodium channel blocker
- decreased synaptic transmission
- fosphenytoin is water soluble pro drug of phenytoin
- oral / IV
- CYP 2C9 inducer
- metabolized in liver
-
excreted renally
- needs dose adjustment in RF, LF
ADVERSE EFFECTS:
- gingival hypertrophy
- hirsutism
- rash
- folic acid depletion
- osteoporosis
- confusion, slurred speech, double vision, ataxia, neuropathy
- SJS, TEN
4
Q
Pregabalin
A
- binds to alpha -2 delta unit of voltage gated calcium channels
- modulates release of glutamate, noradrenaline, substance P.
- inbihits neuronal excitability
- Renal excretion, no hepatic metabolism
- NO CYP metabolism
- no significant drug interactions
Side effects:
- dizziness
- somnolence
- ataxia
- edema
- weight gain
- blurred vision
- asthenia
*
5
Q
Levetiracetam
A
- MOA unknown
- metabolism not in CYP system
- no drug drug interactions
- Dose 500 mg/ IV po bid
- Side effects:
- well tolerated
- fatigue
- dizziness
- resp infection
- mood disturbance
6
Q
Gabapentin
A
- alpah2delta subunit of voltage gated calcium channels
- Presynaptic calcium channel blocker
- not bound to plasma proteins, not metabolized
- no drug drug interactions
- renally excreted, dose adjust in RF
- Dosing 100 mg/day - 900 mg / day
- Side effects:
- sedation
- dizziness
- ataxia
- weight dain
- edema
7
Q
Steroid side effects
A
- Infection
* TB, candida, PJP - Metabolic disturbances
- Hyperglycemia
- electrolytes
- fluid retention
- hyperlipidemia
- Myopathy
- pelvic girdle
- neck flexor and shoulder muscles
- as early as 2-4 weeks
- Bone
- osteoporosis
- reduced Ca absorption in gut, increased calciuria
- GI
- PUD, GIB
- caution with previous ulcer, UGIB, NSAIDS, and intracranial lesions
- Psych
- insomnia
- psychosis
- euphoria
- Adrenal suppression
* after 10 days of at leaset 7.5 mg prednisone/day or 1 mg dex - Dystrophic reactions
- delayed wound healing
- purpura
- dermal atrophy
- Hiccup
- Aseptic necrosis femoral head
- Anaphylaxis
- Ocular toxicity
8
Q
Serotonin Syndrome
A
- SSRIs, MAOI, TCA
HARMED
Hyperthermia
Autonomic instability
Rigidity
Myoclonus
Encephalopathy
Diaphoresis
Symptoms
- shivering
- hyperreflexia / clonus
- myoclonus
- ataxia
- diarrhea
- vomiting
- agitation
- ocular clonus
- rigdity
- hyperthermia
Treatment:
- support
- discontinue serotonergic
- benzodiazepines
- cyproheptadine
9
Q
Neuroleptic malignant syndrome
A
- First generation antipsychotics
- haldol
- all antipsychotics and some D2 antiemetics
FEVER
Fever
Encephalopathy
Vitals sign abn
Elevated WBC/CK
Rigidity
Symptoms
- altered LOC
- RIGIDITY (lead pipe)
- FEVER
- tachycardia
- hypertension or labile BP
- tachypnea
- diaphoresis
Signs
- elevated CK
- leukocytosis
- electrolye abnormalities
Treatment
- d/c meds
- cooling
- clonidine
- benzos
- DVT prophylaxis
10
Q
Anticholinergics
A
Symptoms
Red as a beet, blind as a bat, dry as a bone, mad as a hatter, hot as a desert
- tachycardia
- red /flushed
- anhidrosis
- confused
- hyperthermic
- absent bowel sounds
- urinary retention
- dilated pupils
Rx;
- ABCs
- benzos for seizure
- bicarb for QRS
- physostigmine
11
Q
Pharmacokinetics
A
- What the body does to the drug
- absorption, distribution, metabolism, excretion
12
Q
Pharmacodynamics
A
- What the DRUG does to the BODY
- effect of drugs, receptor binding, enzymes
13
Q
CYP450 overview
A
- liver is primary site of drug metabolism
- enzymatically converts lipid soluble compounds to water soluble compounds for excretion
- Phase 1 and II reactions or both
- Phase I oxidation is catalized by CYP450
- numerous P450 pathways
- not all drugs have CYP activity
- Drugs with cyp activity can be inhibitors, inducers or substrates
- Drugs that inhibit CYP cause increased concentrations of other CYP drugs –> toxicity
- Drugs that induce CYP may reduce other CYP drugs __> subtherapeutic drug levels
14
Q
CYP2D6
A
- encoded by CYP2D6 allele /gene
- expressed in liver and CNS
- responsible for metabolism and elimination of 25% clinically used drugs.
- largest amount of phenotypic variability of all CYPs
- Genetic polymorphism
- poor metabolizer
- intermediate
- extensive (normal)
- ultrarapid metabolizer
- 7-10% causasions lack CYP2D6 enzyme, 70% have functional enzymes
- 2% Asian and African Americans lack CYP2D6, 50% have decreased functioning
- ultrarapid metabolizers more common in MIddle Eastern, North African populations
15
Q
CYP3A4
A
- most common and versatile enzyme in P450 system
- 50% of all drugs
- hemoprotein encoded by CYP3A4 gene
- expressed in liver, intestine (CNS)
- less polymorphism
- important for first pass effect
- Inducers tend to lower plasma concentration of CYP3A4 substrates –> reduced effect
- Inhibitors increase plasma concentrations of CYP3A4 substrates –> toxicity
- Substrate = drug metabolized by CYP3A4
