1. HERB – DRUG INTERACTIONS
Dr.Bidhan Mahajon
PG SCHOLAR
V.P.S.V AYURVEDA COLLEGE,KOTTAKKAL
1

2. Scholar
Dr.Bidhan Mahajon
Guide
Dr. Remadevi.R. MD(AYU)
Professor and H.O.D
2
Department of Dravyaguna Vijnanam
V.P.S.V. Ayurveda College
Kottakkal
2

3. Introduction
• Global Increase
– demand for herbs/herbal formulations
• 25,000 Plant based formulations – Available
• 1.5 Million Practioners of Traditional
Medicinal system
• 25% of all modern medicines – directly
/indirectly derived from plants
• 60% of antitumour and antimircobial
medicines are derived from plants
3

4. • 5 billion/yr industry
• More than 700 therapeutic herbs and
phytomedicines sold in German Pharmacies
• Approximately 70% Physicians prescribe
registered herbal remedies
• 7800 Medicinal drug manufacturing Units India
4

5. Purpose for use of Herbal Medicine?
Health Benefit
Total
Shoppers
(1000)
Female
(711)
Male
(289)
Ensure overall good health
88%
91%
82%
Reduce fat intake
81%
84%
72%
Doctor’s advice
73%
75%
69%
Weight Reduction/Control
73%
76%
67%
Reduce cholesterol levels
72%
74%
66%
Reduce the risk of a specific condition or illness
66%
69%
59%
Improve stamina or energy level
64%
65%
60%
Desire to manage or treat specific health
condition on their own
63%
65%
56%
Cope with food intolerance
48%
50%
43%
Manage Stress
46%
46%
44%
Manage allergies
41%
45%
33%
Slow down the aging process
39%
41%
35%
5

6. 6

7. A MILLION
DOLLAR
QUESTION
SAFETY OF
HERBAL
MEDICINES ?
Answer: Equivocal
7

8. Facts about drug interactions/herbal
medicine/ herb-drug interactions
• Drug interactions - 4th – 6th Cause of death
• At least 100 preoperative fatalities due to
herb -drug/surgery interactions
• >70 – 80 Herbs - Increase risk of
bleeding
• >30 – 40 Herbs possibility of causing
hepatic failure
• Ephedra – 54 deaths , 1600 Adverse
events
• Aloe vera injection – 4 Deaths
• Pennyroyal tea – 2 infants Multiorgan
Dysfunction
• Aristolochic Acid – Death of 100 Belgian
Women
8

9. Interactions between Immunomodulatory
herbs and drugs
Herb
Drug/ Class of
drugs
Mechanism of Herb – Drug
Interaction
Astragalus
(ASTRAGALUS
MEMBRANACEUS)
Azathioprine
Cyclosporine
Methotrexate
Antagonism
Borage
(BORAGO
OFFICINALIS)
Hypnotics
Potentiation
Echinacea
(ECHINACEA
PURPUREA)
Acetaminophen
Potentiation of Hepatotoxicity
Corticosteroids
Cyclosporine
Antagonism
Fexofenadine
Itraconazole
Lovastatin
Inhibition of CYP3A4 leading to
increase in drug concentration
9

10. Ginseng
Digoxin
Increased drug concentrations
Induction of CYP2C9
Opioid
analgesics
Decreased activity of opioids – clear
mechanism is unknown
Phenelzine
and MAO
inhibitors
Increased CNS side effects due to
additive effect
Warfarin
Shankpushpi
(CONVOLVULUS
PLURICAULIS)
Induction of CYP3A4
Hexobarbital
(PANAX
GINSENG)
Amlodipine
Alteration of INR value
Phenytoin
Decreased therapeutic effect
10

11. Interactions between herbs used for
cardiovascular disorders and drugs
• GARLIC
– Antihyperglycemic effect when it was co –
administered with chlorpropamide
– Decreases – bioavailabilty of saquinavir –
induction of P- glycoprotein (P – gP)
11

12. Cont….
GUM GUGGULU (COMMIPHORA
MUKUL)
– It may produce an additive effect with
anticoagulants
– It is believed to act as a thyroid
stimulating agent – avoid the co –
administration with thyroid drugs
– Guggul - predicted to decrease the
absorption of beta blockers and calciumchannel blockers
12

13. Interactions between herbs used for central
nervous system disorders and drugs
Herb
Areca (ARECA
CATECHU)
Drug/Class
of drugs
Procyclidine
Mechanism of Herb Drug Interaction
Antagonistic effect on drug – leading to extra
pyramidal syndrome
Capsicum
ACE
(CAPSICUM
inhibitors
FRUTESCENCE,
CAPSICUM
Theophylline
ANNUM)
Increased risk of developing cough
Chasteberry
(VITEX AGNUS
– CASTUS)
Dopamine
receptor
antagonists
Interferes with the activity of drugs
Feverfew
(TANACETUM
PARTHENIUM)
Antimigraine
Drugs
Potentiation of drug effect
Warfarin
Additive antiplatelet effect due to inhibition of
platelet aggregation
Enhanced bioavailability can lead to theophylline
toxicity
13

14. Ginkgo (GINKGO
BILOBA)
Aspirin
Clopidogrel
Ticlopidine
Increased risk of bleeding
Digoxin
Increased bioavailability of digoxin
Diltiazem
Increased bioavailability of drug
Ibuprofen
Intracerebral mass bleeding due to inhibition of
platelet aggregation
Nicardipine
Induction of CYP 3A4 leading to decreased activity
of drug
Omeprazole
Induction of CYP2C9
Thiazide diuretics
Increase in blood pressure
Trazodone
Induction of CYP3A4
Warfarin
Increased risk of bleeding
14

15. Green tea
(CAMELIA SINENSIS)
Warfarin
Increased risk of bleeding
Guarana(PAULLINIA
CUPANA)
Caffeine/
Respiratory
stimulants
Potentiation of activity
Kava
(PIPER
METHYSTICUM)
Alprazolam
Potentiation of
sedation
Anesthetics
Prolongation of
anesthesia
Levodopa
Antagonism
Lemon balm (MELISSA
OFFICINALIS)
CNS depressants
Additive CNS effects
Thyroid hormones
Inhibits binding of
thyroid hormones to TSH
receptors
Sage (SALVIA
MITILIORRHIZA)
Warfarin
Increased risk of bleeding
Diazepam
Induction of enzymes
15

16. St.John’s wort
(HYPERICUM
PERFORATUM)
Amitryptyline
Induction of CYP3A4
Cyclosporine
Induction of CYP3A4 and P - gP leading to
decrease in drug concentration and rejection
of transplanted organ
Digoxin
Induction of P – gP
Fexofenadine
Inhibition of P - gP
Indinavir,
Saquinavir
Induction of CYP 3A4
Loperamide
Acute delirium – mechanism unknown
16

17. St.John’s wort
(HYPERICUM
PERFORATUM)
Methadone
Induction of CYP 3A4, 2C8 and CYP 2D6
leading to decrease in drug concentration
Oral
Contraceptives
Failure of contraception due to induction of
CYP3A4
Piroxicam
Photosensitizing
drugs
Increased risk of phototoxicity
Quazepam
Induction of CYP 3A4
Sertraline
Inhibits vesicular uptake of monoamines
leading to serotonergic syndrome
Simvastatin
Induction of CYP3A4
Tacrolimus
Immuno graft rejection due to induction of
CYP enzymes
17

18. St.John’s wort
(HYPERICUM
PERFORATUM)
Theophylline
Induction of CYP1A2 leading to decreased
concentration of drug
Thyroid stimulating
hormone
Elevation of TSH levels
Venlaxafine
Serotonin syndrome – Inhibition of
serotonin reuptake and MAO Inhibition
Verapamil
Induction of CYP3A4, leading to decreased
bioavailabilty
Warfarin
Induction of CYP3A4 and CYP2C9
Valerian
(VALERIANA
OFFICINALIS)
Barbiturates
Additive sedation
Yohimbine
(PAUSINYSTALIA
YOHIMBE)
Clomipramine
Increased blood pressure
18

19. Herb – drug interactions due to alteration of
cytochrome P450 enzymes in in - vitro models
Herb
CYP Enzyme
In – vitro model
ANGELICA
DAHURICA
Inhibits CYP3A4
Inhibtis multidrug-resistant and
methicillin-resistant strains of
Staphylococcus aureus
Liver microsomes
Devil’s Claw
(HARPOGOPHYTUM
PROCUMBENS)
CYP2C8,CYP2C19,
CYP3A4,CYP1A2,
CYP2D6
Human kidney (HK-2) proximal
tubule cell line
Echinacea
(ECHINACEA
PURPUREA)
Inhibits
CYP2C19,
CYP2D6
Baculovirus expressed CYP
enzymes
19

20. Herb
CYP Enzyme
In – vitro model
Garlic
( ALLIUM
SATIVUM)
Inhibits CYP2C9,
CYP2C19,
Inhibits CYP3A4
Inhibits CYP2E1
Human liver microsomes
CYP 3A4 Substrates (7Benzyloxyresorufin and 7-ethoxy3 cyanocoumarin
Rat iver microsomal cytochrome
P450 fractions
Ginseng
(PANAX GINSENG)
Inhibits CYP1A2,
CYP2B1,
CYP2C9,CYP3A4
c-DNA-expressed cytochrome
P450 enzyme catalytic activity
Goldenseal
(HYDRASTIS
CANADENSIS)
CYP2D6, CYP3A4,
CYP3A5
Caco – 2 cell lines
Kava
(PIPER
METHYSTICUM)
Inhibits CYP3A4,
CYP1A2, CYP2C9,
CYP2C19,CYP2D6
Human liver microsomes
20

21. Herb
CYP Enzyme
In – vitro model
Liquorice
(GLYCYRRHIZA
GLABRA)
CYP3A4, CYP2C9
Human recombinant enzymes
Schizandra
(SCHIZANDRA
CHINENSIS)
Inhibits CYP3A4
Liver microsomes
Silymarin
(SILYBUM
MARIANUM)
Inhibits CYP3A4
CYP2C9
Human hepatocytes/ Human
recombinant enzymes
Valerian
(VALERIANA
OFFICINALIS)
Inhibits CYP3A4,
CYP2C9 and CYP2C19
Cytochrome P450 CYP3A4
supersomes
Vinca
(CATHARANTHUS
ROSEUS)
Inhibits CYP2D6
Human Liver Microsomes
21

22. Interactions between other herbs and drugs
• Artemesinin
– Artemisinin, - decreases – omeprazole
bioavailability - induction of CYP2C19 activity
(Svensson et al., 1998).
1998
• Foeniculum vulgare
– Decrease the rate of absorption of ciprofloxacin chelation of the drug (Zhu et al., 1999).
1999
22

23. Cont….
• Liquorice
– Antihypertensive drugs - synergistic effect
(Cumming et al., 2003)
– Hydrocortisone - pseudoaldosteronism (Beate
et al., 1999)
– Oral contraceptives - hypertension, edema and
hyperkalemia (Gerty et al., 1997).
23

24. Cont….
•
Silymarin
• potentiate the effects of antiarrhythmic drugs
(Gyonos et al., 2001)
2001
• Increases - pharmacological activity of cisplatin
(Scambia et al., 1996),
1996
• Decreases the blood concentrations of
– indinavir (Piscitelli et al., 2002)
2002
– losartan (Han et al., 2009) and
2009
– metronidazole (Chon et al., 2005)
2005
24

25. Interactions between herbs and drugs acting on blood
B
L
O
O
D
C
L
O
T
T
I
N
G
ALTERATION OF INR
Herbs containing coumarins:
Arnica, celery, chlorella, danshen, dong quai,
chamomile, fenugreek, goldenseal, guar gum, horse
chestnut seeds, papain, passionflower, red clover,
sweet
clover, boldo
Herbs containing vitamin K:
Eg: Acerola, agrimony, stinging nettle, plantain
INHIBITION OF PLATELET AGGREGATION
Bilberry, cayenne, bromelain, capsicum, European
mistletoe, feverfew, garlic
INHIBITION OF PLATELET ACTIVATING
FACTOR (PAF)
Garlic, Ginkgo and saw palmetto
25

26. PREDICTED - HDI
• Bearberry (ARCTOSTAPHYLOUS UVA URSI)
• Estrogens/Oral contraceptives - May ↓ response to estrogen
• Lipid lowering drugs – Possibility of additive effect
• Black Cohosh (CIMIFUGA RACEMOSA)
– Lipid lowering drugs - Possibility of additive effect
• Bladderwrack (FUCUS VESICULOSUS)
– Hypoglycemic drugs - Possibility of additive effect
• Blue Cohosh (CAULOPHYLLUM
THALICTROIDES) - Nitrates and Calcium channel
blockers - May antagonize the hypertensive effect
26

27. • Chamomile (MATRICARIA RECUTITA) Iron - May inhibit iron absorption
• Chaste tree berry (VITEX AGNUS – CASTUS)
- Dopamine receptor antagonists (Phenothiazines) May antagonize drug effect
• Devil’s claw (HARPAGOPHYTUM
PROCUMBENS) - Antiarrhythmic drugs - May
interfere with drug activity
• Echinacea (ECHINACEA PURPUREA) –
Corticosteroids/ Cyclosporine – May nullify the
effect of drug
27

28. • Guarana (PAULLINIA CUPANA)
– Adenosine - May lower response
– Benzodiazepine - Drugs may be less
effective
• Hawthorn (CRATAEGUS LAEVIGATA,
C. MONOGYNA, C. PINNATIFIDA,
C.OXYCANTHA)
– Anesthetics - May enhance hypotension
28

29. Herbs to be avoided prior to
surgery
•
•
•
•
•
•
•
Ephedrine – 24 hrs
Garlic/Garlic products – 7 days
Ginkgo – 36 hrs
Ginseng – 7 days
Kava – 24 hrs
St.Johns Wort – 5 days
Valerian – weeks before
surgery by tapering
29

30. THE OTHER SIDE OF HERB –
DRUG INTERACTIONS
• Aromatic herbs such as ginger can be used to
prevent drug-induced nausea
• Milk thistle can be used to prevent the liver
toxicity associated with drugs
• Capsaicin reduces gastric mucosal damage
induced by aspirin
30

31. Cont….
• Combination of aqueous extract of
Chinese medicinal plant Tripterygium
wilfordi and cyclosporine significantly
increases the heart and kidney allograft
survival compared to cyclosporine alone
• Garlic prevents the formation of toxic
metabolites of paracetamol .
31

32. Cont….
• Co – administration of ginkgo with
antipsychotics (haloperidol) in chronic
schizophrenic patients reduces extra
pyramidal side effects associated with
haloperidol
• Centella asiatica can also be used as an
adjunctive medication for patients with
epilepsy due to its additive anticonvulsant
activity
32

33. Cont….
Momordica charantia is reported to
augment the hypoglycemic effect of
rosiglitazone which can be used to reduce
the dose of rosiglitazone to achieve
enhance therapeutic effect with minimum
side effects
33

34. Cont….
• Piperine can be used as bioavailability
enhancer for several drugs and studies
bolster that piperine enhances the
bioavailability of propranolol which can be
used as a means to achieve better therapeutic
control and improved patience compliance
34

35. Cont….
• Ginseng is considered to be potent
adjuvant for delivery of vaccines which
have been proven to induce higher or
similar antibody titres than vaccines
adjuvanted with aluminium hydroxide
35

36. Cont….
• Rosemary (Rosmarinus officinalis) has
chemopreventive effect as it increases
efflux and intracellular accumulation of
doxorubicin and vinblastine
• Silybinin enhances the antitumour activity
of cisplatin
36

37. 37

38. CONCLUSION
We need to bring into lime light about the
herb – drug interactions
38

39. 39