Transcript Chapter 5 * Herbal Drugs

Chapter 5 – Herbal Drugs
Ephedrine
• Sometimes called herbal X-tacy
• Banned in 2004 by FDA
• Still available in herbal teas & asthma treatment
(dilated bronchioles)
• Also increased heart rate & BP; raises glucose
• Doesn’t enter brain well-jitteriness
• High doses: taken to mimic MDMA and improve
athletic performance-increased heart rate, BP;
feeling of physical activation
• Does nothing to improve muscular dev.
• Minor effects on weight loss
• Adverse Effects: tremors, headache, insomnia,
nausea, vomiting, fatigue, chest pain,
palpitations, seizures
• Major Adverse Effects: elevated blood pressure,
stroke, death-usually from heart attack or stroke
• Bodybuilders-stack ephedrine/caffeine/aspirin
• May be lethal with MAOIs
St. John’s Wort
• Sold as antidepressant
• Taken to prevent depression or improve state of mind
• Compared to FDA approved antidepressants-mixed
results
• Not sure how it works
• Many negative interactions with other drugs
• Stimulates liver enzymes to break down other drugs
(birth control pills; transplant patients)
• With SSRIs-too much serotonin-flushed, jittery; fatal
increase in body temp., BP, heart rate
Melatonin
• a neurotransmitter-structurally related to
serotonin
• Produced by pineal gland, retina, GI tract, and
some immune cells
• Released only at night
• Signals go from eye-brain-pineal gland; then
melatonin released into bloodstream
• 2 types of receptors in brain: MT1 MT2
• Darkness-melatonin released-taken earlier-helps
to fall asleep; helps jet lag
• Important in animal reproduction; may decrease
fertility in humans
• Is an antioxidant (some evidence)
• Can prevent DNA damage in animals; not tested
in humans
• Other reported benefits: improved immune
function, influence GI motility, reverse graying of
hair; not much research
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Safe? Effective dose-unknown
Health food stores 1-5 mg doses
Long-term effects-unknown
May develop tolerance-increase dose to
dangerous levels
Ginseng
• Chinese Medicine-thousands of years
• Today in U.S.-improve athletic performance,
decrease anxiety and stress
• Biologically active ingredients (ginsenosides)
produce some activity in brain
• Improves rats’ abilities to learn mazes
• Human memory studies-mixed results;
problems with methodology
• Lowers glucose in animals; being studied in
humans
• Recommended dose (health food stores) 700 mg
• Content isn’t controlled by any agency
• Effects of single dose-unclear (usually repeated
dosing)
• Acute toxicity-none reported
• Chronic toxicity-unknown
Ginko
• Supposed to improve circulation in small blood
vessels in brain-improve memory and alertness
• Even less research than ginseng
• Recent Alzheimer’s study-some positive effects
• Effects on normal aging-being studied
• Some studies-have shown it’s ineffective
• Danger: can slow down blood clotting
Herbal “Smart Drugs”
• Usually some combo of amino acids
• Normal diet-high protein-already have enough
• Act over hours-don’t produce immediate
“energy boost”
• Even if a neurotransmitter’s production is
increased-doesn’t mean it will produce a
greater effect. Examples:
• Phenylalanine-a precursor of L-tyrosine, Ldopa, & L-dopamine
• Tyrosine-building block for dopamine &
norepinephrine
• Does increased tyrosine=improved mood? Logical, but
not if person is already well-nourished
• Choline-enhances production of ACh; take enough
choline to increase production-fishy smell
• Tryptophan-can enhance production of serotonin-sleep
• Taurine & carnitine-most common additions to energy
drinks-no evidence that either improves memory
Hazards of Herbal Drugs
• Ephedrine-most dangerous-high BP, stroke,
heart attack
• Phenylalanine or tyrosine-dangerous if taking
a MAOI (Nardil); dangerous high BP
• Long-term effects in healthy people-unknown
• Scientific research is increasing