Modificaciones farmacocinéticas en cirugía bariátrica

 Resumen farmacocinético by @DanielG82149631

	Absorción	Distribución	Metabolismo	Excreción
Cambios  fisiológicos	- Restrictiva: disminuye el volumen que puede aceptar el tracto gastrointestinal. - Malabsortiva: bypass estómago-yeyuno/íleon. - Retraso vaciado gástrico y ↓ motilidad intestinal. - ↑ pH gástrico. - ↓ superficie absorción. - ↓ nº transportadores que introducen/expulsan medicamentos. - ↓ contacto con sales biliares. - ↓ circulación enterohepática. - ↓ volumen gástrico.	-  ↓ peso, tejido adiposo y volumen sanguíneo.	-  ↓ nº enzimas digestivas intestinales (malabsortiva). Principalmente: CYP3A4, CYP2C9, CYP2C19, CYP3A5 y glucoproteína-P.	-  ↓ peso à ↓ filtrado glomerular.
Importancia clínica	- ↓ absorción. - ↑ absorción medicamentos básicos y ↓ absorción medicamentos ácidos. - Menor biodisponibilidad para medicamentos que requieren un tiempo prolongado para absorberse (FF de liberación prolongada) - ↓/↑ absorción medicamentos que dependen de transportadores. - ↓ Tmax (cirugía malabsortiva). - ↓ absorción medicamentos liposolubles.   -  ↓ desintegración y disolución de medicamentos orales: Se prefieren las FF masticables (al masticar se aumenta la superficie), abrir cápsulas o en solución para incrementar la absorción. El problema de las soluciones orales es su contenido en azúcares que puede favorecer el dumping.	- ↓ Vd medicamentos liposolubles à ↑ Cp.	- ↓ efecto de primer paso à  ↑ Cp.	-  ↑ excreción.

Monitorización farmacocinética de la vancomicina - Autoevaluación

 

Modelo nonmem de olanzapina (provisional)

Preguntas de farmacocinética

Preguntas de farmacocinética del Dipiro de Farmacoterapia

http://novella.mhhe.com/sites/0071363610/student_view0/chapter4/self_assessment_quiz.html


Self Assessment Quiz - Pharmacokinetics
(See related pages)

1		Clearance determines
			A)	the time to reach steady state.
			B)	the loading dose required to achieve the desired steady-state concentration.
			C)	the maintenance dose required to achieve the desired steady-state concentration.
			D)	the dosage interval.
			E)	a and d.
2		Volume of distribution determines
			A)	the time to reach steady state.
			B)	the loading dose required to achieve the desired steady-state concentration.
			C)	the maintenance dose required to achieve the desired steady-state concentration.
			D)	the dosage interval.
			E)	a and d.
3		Half-life determines
			A)	the time to reach steady state.
			B)	the loading dose required to achieve the desired steady-state concentration.
			C)	the maintenance dose required to achieve the desired steady-state concentration.
			D)	the dosage interval.
			E)	a and d.
4		Clearance is
			A)	dependent on the value of volume of distribution.
			B)	dependent on the value of half-life.
			C)	a function of the blood flow to clearing organs and the efficiency of the organ in extracting the drug.
			D)	a function of the physiologic volume of blood and tissues and how the drug binds in blood and tissues.
			E)	a and b.
5		The volume of distribution is
			A)	dependent on the value of clearance.
			B)	dependent on the value of half-life.
			C)	a function of the blood flow to clearing organs and the efficiency of the organ in extracting the drug.
			D)	a function of the physiologic volume of blood and tissues and how the drug binds in blood and tissues.
			E)	a and b.
6		The half-life is
			A)	dependent on the value of volume of distribution.
			B)	dependent on the value of clearance.
			C)	a function of the blood flow to clearing organs and the efficiency of the organ in extracting the drug.
			D)	a function of the physiologic volume of blood and tissues and how the drug binds in blood and tissues.
			E)	a and b.
7		Linear pharmacokinetics means
			A)	drug serum concentrations decrease in a straight line when plotted on a concentration-time graph.
			B)	drug serum concentrations decrease in a straight line when plotted on a log concentration-time graph.
			C)	steady-state drug serum concentrations change proportionally to dose.
			D)	steady-state drug serum concentrations change nonproportionally to dose.
8		Nonlinear pharmacokinetics means
			A)	drug serum concentrations decrease in a straight line when plotted on a concentration-time graph.
			B)	drug serum concentrations decrease in a straight line when plotted on a log concentration-time graph.
			C)	steady-state drug serum concentrations change proportionally to dose.
			D)	steady-state drug serum concentrations change nonproportionally to dose.
9		Most drugs follow nonlinear pharmacokinetics.
			A)	True
			B)	False
10		Pharmacokinetic models are useful to
			A)	describe concentration-time data sets.
			B)	predict drug serum concentrations after several doses or after different routes of administration.
			C)	calculate pharmacokinetic constants (clearance, volume of distribution, half-life).
			D)	a and c
			E)	a, b, and c
11		Factors to be considered when prescribing the best drug dose of a patient include
			A)	age.
			B)	gender.
			C)	weight.
			D)	other concurrent disease states and drug therapies.
			E)	all of the above.
12		Clinicians should begin considering dosage adjustment of renally eliminated drugs at what creatinine clearance value?
			A)	90 mL/min
			B)	60 mL/min
			C)	30 mL/min
			D)	15 mL/min
13		Clinicians should begin considering dosage adjustment of heaptically eliminated drugs at what Child-Pugh score value?
			A)	1
			B)	3
			C)	5
			D)	8
			E)	10
14		The enzyme system responsible for the metabolism of most drugs is
			A)	P-glycoprotein.
			B)	alkaline phosphatase.
			C)	creatine kinase.
			D)	cytochrome P-450.
			E)	HMG-CoA.
15		If pharmacologic effect is plotted versus drug concentration for most agents, the shape of the graph is
			A)	linear.
			B)	hyperbolic.
			C)	parabolic.
			D)	trapazoidal.