CHEMISTRY MEDICINES AND

DRUGS

STIMULANTS

Stimulants are drugs that > stimulate the brain and the central nervous system> increase the state of mental alertness> decrease appetite

A) AmphetaminesB) CaffeineC) Nicotine

Adrenaline (epinephrine) is a natural stimulant produced in the adrenal gland.> it is released when in stress or fear> it controls

- heart/breathing rate- pupil dilation- sweating

AMPHETAMINES• Amphetamines are chemically related to adrenaline.

•They both derive from phenylethylamine.

•They are sympathomimetic drugs which mimic the effect of stimulation on the nervous system by increasing the levels of dopamine.

• Amphetamines were initially used to treat narcolepsy and in WW II were used by soldiers to combat fatigue. • Later during the 50’s and 60’s they were used as slimming pills.• Regular use can lead to both tolerance & dependence.

• Short-term effects:- increase in heart rate and breathing- insomnia- dilation of the pupils- decrease in appetite- possible fatigue and depression

• Long-term effects:- weight loss- constipation- emotional instability- dependence

Phenylethylamine

(love molecule)

- “high” feeling of lovers- also found in chocolate

Dopamine

Transmits to neurons signals of

- joy- happiness- excitement

Amphetamine

- stimulant- suppresses appetite- treats narcolepsy

Methamphetamine (“speed”)

- potent stimulant- very addictive- severe withdrawal symptoms- “meth mouth”

Ecstasy

- potent stimulant- designer drug- can be fatal- neurotoxic

CAFFEINE

• It is the most widely used stimulant in the world.

• It is present in coffee, tea, chocolate and cola drinks and is also found in some pain killers or other medicines.

• People that consuming 400 mg of caffeine a day may have dependence & physical side effects.

• Like nicotine, morphine, codeine and cocaine, caffeine is also an alkaloid.alkaloid.

• Alkaloids are nitrogen-containing compounds of plant origin containing heterocyclic rings and a tertiary amine group.

• Theobromine has a similar structure to caffeine, which is also found in chocolate. (It does not contain bromine!)

caffeine theobromine

• Effects at low doses:- respiratory stimulant- weak diuretic- enhances concentration and alertness- reduces migraines (constriction of blood vessels)

• Effects at high doses:- anxiety- irritability- sleeplessness

NICOTINE• One third of the world’s population is addicted to smoking because tobacco contains nicotine

•Nicotine produces psychological and/or physical dependence

•Nicotine builds up tolerance

• Stopping smoking can produce temporary symptoms like a craving for tobacco, nausea, weight gain, insomnia, irritability and depression

• Short-term effects:- stimulates nervous system- increases heart rate and blood pressure- increases concentration- constricts blood vessels- stresses heart- reduces urine output

Long-term effects:- increases risk of heart disease coronary thrombosis- inhibits ability of blood to carry oxygen (CO)- excess acidity > peptic ulcers- mouth/lung cancer- adverse effects on pregnancy

Both compounds are heterocyclic with one or more carbon atoms in the ring replaced by nitrogen atoms.

They both contain a tertiary amine group

caffeine nicotine