Obesity treatments Flashcards
how do most people maintain constant body fat and weight
homeostatic mechanisms that control energy balance
how does obesity happen if the body should have homeostatic mechanisms that control energy balance
disturbance in these mechanisms, genetic influence, food, activity, social and cultural things
what is the current view in obesity causes
susceptibility cause by genes, expression determined by environment
what are 2 things that can disturb homeostasis
- types of food (mechanisms respond slower to fat than protein)
- quantity of food (if previously obese, need less calories to maintain weight than if never been obese)
what are 4 therapeutic strategies for obesity
- modulate fat metabolism/storage (diet exercise)
- reduce food intake, amplify satiety signals/ block hunger signals
- block nutrient absorption in intestine
- increase thermogenesis (increase metabolism, dissipate food energy as heat)
what is sibutramine (generally what does it do to person)
a drug that regulates food intake, enhances satiety (appetite suppressant)
what is the mechanism of action of sibutramine
inhibits 5-HT, DA and NA uptake at hypothalamic sites that regulate food intake (ARC)
which drug is the SSRI anorexic
sibutramine
what are the beneficial effects of sibutramine
decrease food intake (ARC), weight loss (thermogenesis!), less plasma TGs, increased HDL
how does sibutramine cause weight loss (diff than decreased food intake)
higher energy expenditure through thermogenesis mediated by sympathetic nervous system)
why was sibutramine withdrawn from maker
increased BP and HR
what is a similar drug to sibutramine that also got withdrawn from the market
lorcaserin
what is the mechanism of action of lorcaserin and what does it cause
5-HT2C receptor agonist that suppresses appetite (weight loss too)
what are 2 main drugs that are used to increased thermogenesis
phentermine and topiramate
what is phentermine mechanism
sympathomimetic by preventing NA uptake, more NA in CNS to enhance satiety and more NA in periphery for thermogenesis
what are 3 side effects of phentermine and why
high BP and HR (sympathetic stimulation) and potential for addiction
what is topiramte mechanism
GABA signalling enhancer, blocks neuronal Na+ channels, activates K+ channels
what does topiramate do for obesity
it enhances satiety
where are 5-HT2C neurons most found
in hypothalamic POMC producing neurons
what does 5-HT2C activation cause
release of alpha-MSH which activates anorexogenic pathways
what does alpha-MSH do
activates anorexogenic pathways
why is lorcaserin slightly safer than some other drugs
low affinity for other 5-HT subtypes (like 2B) which have been associated with developing valvular heart diseases
what is a main drug that is used to block nutrient absorption
orlistat
what is the mechanism of orlistat
irreversible inhibitor of gastric and pancreatic lipases
