Performance and Drugs: Stimulants

What are the WADA regulations regarding stimulants?

• banned in competition

Are caffeine and nicotine prohibited?

• no

When is Cathine considered prohibited?

• urine concentration greater than 5 micrograms per mL

When is Ephedrine and methylephedrine prohibited?

• urine concentration greater than 10 micrograms per mL

Epinephrine (adrenaline) is not prohibited when?

• local administration

• e.g. nasal, ophthalmologic, co-administered with local anesthetic agents

when is pseudoephedrine prohibited?

• urine concentration greater than 150 micrograms per mL

What is a stimulant?

• substance that raises levels of physiological or nervous activity

How do stimulants work?

• mimic effects of neurotransmitters

• elevate the levels of transmitters at their site of action by increasing their release, preventing reuptake or reducing metabolism

What are the different types of stimulants?

• sympathomimetic amines

• psychomotor stimulants

• central nervous system (CNS) stimulants

What do CNS stimulants do?

• increase the respiratory and vasomotor centers of the CNS

• increase reflex excitability

Why is there limited misuse of CNS stimulants?

• if you can’t control effects, leas to decreased performance

What do sympathomimetic amines do?

• mimic or potentiate the effects of SNS

What do sympathomimetic amines act through?

• Norepinephrine

• displacing from storage or act on same receptors (bind and don’t leave)

How do sympathomimetic amines work?

• mimic effects of NE both indirectly and by direct receptor activation

• Indirectly, they promote the release and inhibit the reuptake of NE

What are the effects of sympathomimetic amines?

• increase HR—→increase cardiac output

• increase BP

• increase bronchodilation

• increased alertness and arousal

• decrease fatigue perception

Examples of Sympathomimetic amines

• ephedrine

• methyl ephedrine

• pseudoephedrine

• cathine

Ephedrine is similar to____

• amphetamine

The biological potency of ephedrine is ____

• 25 fold lower

What % of NCAA athletes, HS boys/girls have used ephedrine?

• NCAA: 35:

• HS boys: 12%

• HS girls: 26%

What is cathine synthesized from? Its actions are similar to___

• khat plant

• similar to amphetamine

How do sympathomimetic amines effect performance?

• small effects on power, endurance, strength and speed

• short term weight loss

What do psychomotor stimulants do and why are they used?

• affect mental function and behavior

• excitement, euphoria, increased motor activity, reduced fatigue

Examples of psychomotor stimulants

• Amphetamines

• Cocaine and methylxanthines

Where are amphetamines absorbed? When is peak plasma concentration?

• absorbed from small intestine

• peak plasma concentration 1-2 hours following administration

Depending on the individual, amphetamines may cause?

• increase in general energy, mental aptitude, talkativeness, restlessness, vigor, excitement and good humor

Amphetamines may induce___

• drug dependence

• mental/physical depression from withdraw

What are the 4 mechanisms of amphetamines?

• release of neurotransmitter from respective nerve terminal

• inhibition of monoamine oxidase activity—→ wine and cheese syndrome

• inhibition of neurotransmitter reuptake

• direct action on neurotransmitter receptors

Side effects of amphetamines

• tachycardia

• hypertension

• restlessness

• anxiety

• rapid breathing

How might amphetamines effect performance?

• improved reaction time when fatigued

• increased muscular strength/endurance

• increased acceleration

• increased aerobic capacity

• stimulated metabolism by inducing loss of body fat

Cocaine affects the _____

• CNS

• may inhibit catecholamine reuptake

How is cocaine administered?

• snorting

• absorbed into blood by nasal tissue and sensory cells of olfactory nerve

When are the peak effects seen?

• 5-15 minutes lasting for an hour

• freebase- peak less than 1 minute, but short lived

Does cocaine improve performance?

• no

• grandiose feelings make athletes misjudge performance

• impaired thermoregulation, early fatigue, muscle glycogen depletion

what does methylhexanamine do?

• release noradrenaline from nerve endings

What dietary supplements are methylhexanamine marketed as?

• DMAA (off market)

• DMP (on market)