Herbals Flashcards
Current regulation stems from
1994 FDA created supplement category
Requires no proof of efficacy or safety
No quality controls
Exempt from pharm. regulations
Can supplements claim to cure anything?
No, but they may claim specific effects, such as “boosts immunity”
Lack of regulation leads to
Unknowns regarding- Active ingredients Bioavailability Proper dosage Consistency Contaminants
Why do manufacturers not conduct safety studies
Not required to
Expensive and unlikely to recoup the costs
Does the FDA issue warnings about potential problems with supplements?
No, in the past they did, but too numerous to continue to do so
What is the industry group that offers safety recommendations regarding supplements
American Herbal Product Association
What are the safety classes used by the AHPA
Class 1- safe when used appropriately
Class 2- External use only, not to be used when nursing/pregnant
Class 3- Only to be used under the supervision on an expert
Class 4- Insufficient data
How large is the supplement market
$63 billion in 2003
35% of the population takes some form
What percentage of patients continue to use herbals prior to surgery
About 23%
Half of those take multiple products and a quarter also take Rx drugs
What percentage of pts do not report supplement use to anesthesia providers
70%
Profile of common herbal users
Female, 40-60
White
College education
Neuro/OB/GYN procedures
Most commonly used herbals in the US
Echinacea Gingko St.John's wort Garlic Ginseng Saw palmetto Ephedra Valerian Kava
How do herbals affect periop course
Direct effects
Dynamic interactions (alters effects of other meds)
Kinetic interactions (altered metabolism/elimination of other drugs)
Specific anesthesia concerns
Prolong effects of anesthetic agents Increased bleeding risk Hypo/hypertension Hypoglycemia Hepatotoxicity
What are the current recommendations regarding herbals and surgery
Discontinue 14 days prior to surg
Kava kava
CNS depressant, sedative, anxiolytic
Additive to anesthetics
Potential withdraw/addiction potential
SE: HA, dizziness, sluggishness, GI upset
Long term use may cause scaly skin, yellowing of skin/nails, photosensitivity, and hepatotoxicity
Valerian
Sedative, anxiolytic, sleep aid
Increase sedative effects of anesthetics, avoid with barbs, opioids, and benzos
SE: HA, excitability, ataxia, GI upset
Can develop withdrawal- delirium, CV instability
St. John’s wort
Used for depression
SE: allergic reactions, HA, dizziness, restlessness, fatigue, GI upset, photosensitivity, additive effects with anesthesia
Caution with MAOIs (serotonin syndrome)
Induces CYP450 (Indinavir, cyclosporine, dig, CCBs, BBs, phenobarb, phenytoin, birth control, benzos, coumadin, alfentanil, lidocaine, steroids, NSAIDs
Gingko
Used for cognitive function and to improve circulation
SE: HA, dizziness, GI upset, dermal sensitivity
Can increase risk of bleeding, especially with other platelet inhibitors, coumadin, ASA/NSAIDS
Garlic
Inhibits platelets, increases fibrinolysis, treats HTN/Cholesterol. May have anticancer properties.
Concerns- increased risk of bleeding, especially with platelet inhibitors and warfarin
Can create hypotension
Ginseng
Lowers blood glucose, inhibits platelets, used to enhance mood/energy and protect against stress
Concerns- nervousness, excitation, tachycardia, inability to concentrate, insomnia, HA, HTN, epistaxis, allergies, water/e-lyte imbalances.
Hypoglycemia
Increased bleeding risk with anticoagulants. Avoid with ASA/NSAIDS.
May DECREASE effectiveness of warfarin
Saw palmetto
Used for BPH
May have anti inflammatory properties (Inhibits COX, platelets)–> may increase bleeding
Ephedra
Direct and indirect sympathomimetic, CNS stimulant. Its basically ephedrine.
Used for weight loss, increased energy, asthma
Concerns- HTN, tachycardia, arrhythmias, vasospasm, MI, myocarditis, stroke, agitation, anxiety, psychosis, panic attacks
Can develop tachyphylaxis
Life threatening interactions with MAOIs
Banned in 2003, but still available in Utah, also online
Echinacea
Short-term immune stimulation. Used for prophylaxis, infections, esp URIs
Concerns- allergic reactions (in asthma, atopy, rhinitis), decreased effectiveness of immunosuppressants, may lead to overstimulation (avoid in tuberculosis, leukosis, MS, HIV, DM, other autoimmune disorders)
Worsens control in diabetic pts- hypoglycemia
Hepatotoxic
Melatonin
Hormone that controls sleep-wake cycle
Used for insomnia, jet lag, shift work sleep aid
Readily crosses BBB, increases sedative effects of benzos. Has been studied as a pre op anxiolytic drug.
May interact with anticoags, immunosuppressants, DM meds, BCP
Pre-op assessment
Specifically address herbals
List agents used, dose, frequency, duration
Source, potential side effects
D/C prior to surg, especially for coags, CNS, and blood glucose altering agents
Check appropriate labs if not stopped
