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
what are the effects of b2 adrenoceptors during sport
- bronchodilation
- increase blood flow to skeletal muscle and skin
- growth/speed of contraction of skeletal muscle
- liver glycogenolysis
what are the potential advantages of taking beta blockers in sport
- reduce HR and stress
- stop hands and bodies shaking while competing in precision sports that require accuracy
what are the potential disadvantages of taking beta blockers in sport
- lower BP and HR
- reflex vasoconstriction via alpha 1 adrenoceptors
- non selective block of B2 adrenoceptors –> bronchoconstriction
- fatigue
what are the potential advantages of taking beta2 agonists in sport if taken systemically
- increased skeletal muscle blood flow –> increases oxygen supply and lactic acid removal reduces fatigue
- exerts anabolic effect –> increase muscle mass –> increase strength
- exerts catabolic effect to reduce body weight
potential side effects of taking beta2 agonists in sport
- tachycardia
- muscle tremor
what is the banned status of taking beta2 agonists in sport
- prohibited for any route other than inhalation - need to have <1ug/ml in the urine
what are the potential advantages of taking glucocorticoids in sport
Mask pain!
- anti-inflammatory actions
what are the potential disadvantages of taking glucocorticoids in sport
- damage to tissues used before full recovery
- chronic use can cause Cushing syndrome
what are the potential advantages of taking androgens in sport
- increase muscle strength by encouraging new growth
- allows the athlete to train harder longer
what are the potential advantages of taking growth hormone in sport
- reduced fat mass
- increased lean mass
- increased bone density
what are the potential disadvantages of taking GH in sport
- joint pain
- increased risk of diabetes
- acromegaly
