Phmkntx- 20A Flashcards
Define number needed to treat.
- used to compare efficacy of 2 treatments
- it is the average # of patients who need to be treated for 1 additional patient to benefit
- the lower the NNT, the more effective the treatment
What is absolute risk reduction.
ARR= difference in treatment response between two treatment groups
Formula for NNT
NNT=1/ARR
What is number needed to harm
- compares the risk of adverse event between 2 treatments
- the average # of pts who need to be exposed to a risk factor for 1 additional pt to be harmed
- the higher the NNH, the safe the treatment
Name the 4 components of pharmacokinetics
- pharmaco (drug), kinetics (movement)
- AD ME
- Absorption
- Distribution
- Metabolism
- Elimination
Question about pt with GI upset on the exam is a clue about
-altered or decreased absorption
What do we need to remember about old people?
- the older we get, the drier we become
- very susceptible to lithium toxicity, and elevated alcohol levels
- more total body fat, less body water
- increased VOD lipophilic drugs therefore decreased peak serum levels
CYP450 enzyme system is the majority of which phase of metabolism
- PHASE I
- puts on a handle
What is the main goal of drug metabolism?
-get rid of the foreign material (drug)
What is the main goal of phase I metabolism
-to prepare drug for phase II metabolism
Name drugs that induce P450 system
- phenobarbital
- cigarette smoke
- St. John’s wort
- carbabmazepine
Name drugs that inhibit P450 system
- Fluoxetine
- Valproate (also inhibitor of phase II metabolism)
- Ketoconazole
Which P450 does Carbamazepine induce?
-3A4
Which drugs does Carbamazepine reduce (increase the metabolism of)
- carbamazepine (autoinduction)
- valproate
- haloperidol
- protease inhibitors
- OCPs
- midazolam
- vincristine
Other drugs that induce 3A4
-Phenytoin
