M5S2 Herbal Drugs

Question 1

Herbal drugs

Answer 1

Refers to plants or plant parts that used to prevent or treat illness or improve health
-approximately 80% of worlds population is reported to use herbal drugs for treatment of illness and disease
-use of herbal drugs is gaining popularity in Canada

Question 2

Factors that drive herbal drug use

Answer 2

General public
-due to public wanting to use natural products as believe safer than conventional or allopathic medications
-both natural and human made chemicals can be toxic tho
-in fact, botulinum toxin, which produced naturally by microorganism is one of most toxic substances

Manufacturers and retailers
-promote these products for financial gain
-estimates sales of herbal products in Canada are excess of 2 billion dollars annually

Question 3

History of herbal drugs

Answer 3

-practice of medicine prior to 1940s depended on large number of natural products including opium
-1950s heralded to era of purified natural product (ex. Morphine replaced opium)
-pharmaceutical industry developed thousands of synthetic drugs
-many of todays drugs derived from these natural sources

Question 4

Classifications of medicinal/herbal products

Answer 4

Allopathic medicine
-drugs used by mainstream medicine
-have drug identification number (DIN) from health Canada and have undergone full testing for safety and efficacy

Herbal medicine
-plant products being sold to treat a condition and do not have DIN
-products often unpurified, lacking phase 3 clinical trial data

Phytopharmaceuticals
-drugs obtained from plants which purified and used at therapeutic doses with scientific evidence of efficacy and documented toxicity

Allopathic phytopharmaceuticals
-drugs obtained and purified from plants that meet all requirements of drug (ie full safety and efficacy evaluated, DIN) and therefore have full status as a drug

Question 5

Value of plants for pharmaceuticals

Answer 5

-number of uses in preparation of both herbal and allopathic drugs
-direct source for some therapeutic agents
-plants also provide source of raw material for manufacture of modified semi-synthetic compounds with altered properties, such as increased efficacy

Question 6

Problems associated with herbals: lack of efficacy and safety data

Answer 6

-lack of randomized controlled trials evaluating efficacy and safety of herbals
-RCTs only been conducted for few herbals
-in 2004, Canada introduced new regulations that began the process of better regulations for herbal products to ensure their efficacy and safety

Question 7

Problems associated with herbals: interpreting the literature

Answer 7

-literature aimed at general public often overstates efficacy of herbal preparations
-natural medicines comprehensive database recognized as go-to resource for evidence-based information on herbal medicines
-database rates effectiveness of herbal products on safe: effective, likely effective, possibly effective, likely ineffective, possibility ineffective, to insufficient evidence to rate effectiveness

Question 8

Additional problems associated with herbals

Answer 8

Lack of standardization
-current legislation should address the problem of quality control during manufacture of herbal products
-compliance with appropriate standards of purity and content will depend on extent of inspections by health Canada

Intentional adulteration
-addition of substances other than herbal
-ex. Inactive materials and dyes to increase weight, and allopathic drugs to increase effectiveness of drugs, such as cocaine, NSAIDs, estrogens, and/or sildenafil (viagra) found in herbals marketed as pure substances

Differing global standards
-manufacturing facilities and processes in other countries may not be inspected using same standards used in Canada

Drug interactions with alliopathic medicines
-number of drug-drug interactions occur between prescription and herbal drugs
-therefore important to inform physicians of the use of any herbal medications

Question 9

Allopathic medicine

Answer 9

drugs used by mainstream medicine that have undergone full testing for safety and efficacy

Question 10

Herbal medicine

Answer 10

Plant products sold as medicine but evaluation, especially efficacy, is lacking

Question 11

Allopathic phytopharmaceuticals

Answer 11

A plant-derived product that meets full status as a drug, having passed all allopathic drug requirements

Question 12

Phytopharmaceuticals

Answer 12

Drugs obtained from plants, which are purified, and used at the therapeutic doses with scientific evidence of efficacy and documented toxicity

Question 13

Overview of herbal drug: St. John’s wort

Answer 13

-likely effective for mild to moderate depression and mild wound treatment
-active ingredients are hypericin and hyperforin, which have true antidepressant activity
-less effective than other antidepressants (ex. Tricyclic antidepressants or serotonin reuptake inhibitors) but superior to placebo in mild to moderate depression
Toxicities:
-syndrome that manifests as confusion, agitation, shivering, fever, sweating, diarrhea, muscle spasms, tremor
-can cause phototoxicity (drug is deposited in skin, and sunlight breaks down drug causing skin reaction or rash)
-should not be taken with other antidepressants, as increase the risk of adverse effects like serotonin syndrome
-some products contain St. John’s Wort and Ephedra (phen-fen). Product should be avoided due to additive CNS excitation

Question 14

Herbal drug: aloe Vera

Answer 14

-possibly effective for cold sores and minor skin irritations
-applied topically in gel or cream as aid in healing of wounds and burns
-active ingredients are mannans and anthraquinones
-mechanism of action in would healing thought to be increase in micro circulation of skin
-upon ingestion, causes severe diarrhea
-ingestion should be avoided
-cleopatra reportedly used aloe to protect her skin from ravages of Egyptian sun

Question 15

Herbal drug: devils claw

Answer 15

-possibly effective for osteoarthritis and back pain, and insufficient evidence for all other suggested indications
-recommended for number of ailments ranging from migraine to kidney disease but mainly used for treatment of inflammatory conditions
-active ingredients believed to be class of compounds known as iridoid glycosides, and possible have some anti-inflammatory properties but studies suggest inactivated in acid of stomach
Toxicities:
-number of different ones but most common is diarrhea

Question 16

herbal drugs: Panax ginseng

Answer 16

-possibly effective for thinking, memory, erectile dysfunction, multiple-sclerosis related fatigue, sexual arousal, and reducing risk of developing influenza
-enhance memory, learning, productivity and immune system plus reduce blood sugar in diabetic person
-active ingredients are ginsenosides and panazosides
-proper randomized controlled trials are lacking
Toxicities:
-include headache, high blood pressure and bleeding
-also increase insulin levels in blood therefore diabetic taking insulin should not also take ginseng

Question 17

Herbal drugs: echinacea

Answer 17

-possibly effective for common cold and insufficient evidence for all other indications
-recommended for prevention and treatment of common cold, for wound healing and as an anti-inflammatory agent
-active ingredients are echinacein, cichoric acid, and caffeic acid
-number of studies found that echinacea extracts can stimulate T-lymphocytes (cell involved in immunity)
Toxicities of echinacea
-use of echinacea are rare
-patients with autoimmune disease (ex. Lupus) should not use this herbal, as any effect on immune system could make these conditions worse

Echinacea study review
-a 2011 study compared blinded echinacea, open label echinacea (patients know they were taking it), blinded placebo, and no treatment (open label placebo). Endpoint measured was duration of colds in days. Average response was 24 reduction in duration of cold, a threshold not reached. Placebo effect was determined

Question 18

Herbal drugs: valerian

Answer 18

-possibly effective for mild insomnia, and insufficient evidence for all other indications
-recommend valerian for treatment of anxiety and panic attacks (ie. sedative-hypnotic)
-active ingredients are group of compounds known as valepotriates
Toxicities:
-liver toxicity
-CNS depressant properties of valerian may impair the ability to operate a motor vehicle

Question 19

To improve manufacturing and safety of herbal products

Answer 19

1. Appropriate standards for content and purity of purposed active ingredients need to be ensured
2. Efficacy of these products need to be determined in randomized controlled trials
3. Valid toxicity testing needs to be completed
4. Herbal products that do possess some pharmacological activity need to be compared to current array of allopathic compounds available to treat those conditions