drug interactions with exercise Flashcards
explain the plasma insulin levels at rest and during exercise
exercise>rest
what are the mechanisms that can contribute to exercise-induced hypoglycaemia
- accelerated insulin absorption from sites near exercising muscles
- exercise-mediated enhancement of insulin action
- lack of decline in insulin secretion during exercise
what are the mechanisms that can contribute to exercise-induced hyperglycaemia
- excessive carbohydrate supplementation
- too large a reduction in insulin dose prior to exercise
explain the plasma GTN levels at rest and during exercise
exercise>rest
what are the mechanisms that contribute to the increased plasma levels of GTN with exercise
- increased skin blood flow
- increased kinetic energy of drugs with increased skin temp
- increased hydration may improve absorption of drugs
(with transdermal administration)
what are the negative effects of GTN during exercise
there is the potential for vasodilation of the skin vasculature –> can cause excessive hypotension and divert coronary blood flow
explain the plasma salbutamol levels at rest and during exercise
exercise>rest
what are the mechanisms that contribute to the increased plasma levels of salbutamol with exercise
- increased respiratory rate
- increased pulmonary blood flow
- increased epithelial permeability
what are the drug effects of exercise on the gut
- inhibits gastric emptying (reducing drug delivery to the small intestine)
- increases intestinal motility to reduce transit time (less time for absorption of lipophilic drugs)
explain the plasma walfarin levels at rest and during exercise
rest>exercise
what are the mechanisms that contribute to the increased plasma levels of warfarin at rest compared to at exercise
- increased binding of warfarin to albumin –> decreased free warfarin
- possible increased metabolism with training
what is the effect of warfarin during exercise
shorter clotting time compared to at rest
explain the plasma and muscle digoxin levels at rest and during exercise
plasma - rest>exercise
muscle - exercise>rest
what is the mechanism that contributes to the decreased digoxin level during exercise
redistribution due to increased binding to skeletal muscle
what is the implication of the decreased plasma digoxin level during exercise
reduced efficacy to increase contractility or control rate
what is the difference between propranolol, atenolol and carvedilol plasma levels during rest and exercise
propranolol = exercise>rest atenolol = exercise>rest carvedilol = exercise=rest
what is the mechanism behind the increased plasma level of propranolol with exercise
due to reduced hepatic clearance
metabolism highly dependent on hepatic blood flow
what is the mechanism behind the increased plasma level of atenolol with exercise
reduced renal clearance
excretion highly dependent on renal blood flow
what are the implications of having a higher plasma level of beta blockers during exercise
increased risk of exercise-limiting adverse effects (bronchoconstriction, fatigue)
for a substance/method to be prohibited by the WADA - what are the conditions that have to be fulfilled
- potential to enhance, or does enhance performance in sport
- potential risk to athlete’s health
- WADA has determined that the substance or method violates the spirit of sport
in what ways can drugs enhance an athletes performance
- relax the body
- increase oxygen delivery
- remove lactic acid in exercising tissues
- mask pain
- reduce weight
- build mass and strength of muscles and/or bones
how can diuretics cause a potential advantage in sport
- loss of fluid can reduce weight
- dilution of urine will decrease concentration of other banned drugs
what are the potential disadvantages of taking diuretics in sport
- dehydration
- hypokalaemia
what are the effects of b1 adrenoceptors during sport
- increase HR
- increase SV
- increase lipolysis
