Herbal medicines have the potential to interact with conventional drugs when taken together through pharmacokinetic and pharmacodynamic mechanisms. An estimated 5-20% of people use herbal medicines which can interact in various ways like altering absorption, metabolism, or excretion of drugs. Some common herb-drug interactions involve garlic, ginger, black pepper, cinnamon, and green tea potentially impacting drugs like anticoagulants, antidiabetics, and antibiotics. Healthcare professionals have an important role in advising patients about monitoring herb-drug combinations and collecting data on suspected interactions to improve safety.

1. PRESENTED BY
Under the guidance
of
T.SRI KRISHNA*
S.RUPESH KUMAR
4th YEAR B.PHARM

2. HERB-DRUG INTERACTIONS
INTRODUCTION

When Herbal Medicinal Products and Western drugs
administered together may interact each other in body
leading to kinetic and dynamic alterations
 Herbs are often administered in combination with
therapeutic drugs, raising the potential of herb-drug
interactions.

1.
2.
3.
An estimated 5-20% of general people consume
herbal medicines because
Naturally available
Consideration of safe to use
Ready available

3. Adverse Events and Drug-Interaction Caused by Herbal
or Traditional Medicines by the study of
– ANIMAL STUDY
– CONTROLLED TRIAL
– SINGLE CASE REPORT
– MULTIPLE CASE REPORTS

4. 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

5. HERB-DRUG INTERACTIONS
PHARMACOKINETIC
Modify metabolic
pathways in body
Mainly occur in
GIT
Kidney
Liver
PHARMACODYNAMIC
Related to action of
herb and drug
Interactions can be
predicted
Antagonism or
Synergism

6. INCREASED
DECREASED
ABSORPTION
Ginger
Green Tea
Black Pepper
Fibres
Mucilage herbs
METABOLISM
Guggul
Grape fruit
ELIMINATION
Laxative
Diuretic herbs
Liquorice

7. oClinicians lack of adequate knowledge
combinations
oNo quality assurance for purity and
potency
oNo advancement in research

8. GARLIC:
– May ↑ bleeding times with
anticoagulants
– ↓ blood levels and toxicity of protease
inhibitors like ritonavir, indinavir….etc
GINGER:
 May ↑ bleeding with anticoagulants
↓ effect of antacids
Ginger might decrease blood sugar
Insulin, Chlorpropamide , Glipizide, Tolbutamide
High blood pressure (Calcium channel blockers)
interacts with GINGER
verapamil , felodipine , amlodipin

9. Black and white pepper might decrease
how quickly the liver breaks down some
medications
 lovastatin (Mevacor)
 ketoconazole (Nizoral)
 Itraconazole (Sporanox), …etc.
It will decrease the action of antacids
The black pepper majorly shows interaction and
increase the AUC of The drugs are:
Phenytoin (Dilantin)
Carbamazepine (Tegretol) tranquilizers
in healthy volunteers
Propranolol (Inderal)
Rifampin
Theophylline in patients with pulmonary tuberculosis.

10. Taking cinnamon bark along with diabetes
medications might cause your blood sugar to go too
low.
Some medications used for diabetes include glimepiride (Amaryl), glyburide
(DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos),
rosiglitazone (Avandia), and others.
Decreased effectiveness of Fluoroquinolones, Increased risk
of photo toxicity with tetracycline's
It increase the AUC of anti hypertensive's.
Medications that can harm the liver (Hepatotoxic drugs) interacts with
CASSIA CINNAMON
 these are miodarone, carbamazepine (Tegretol), isoniazid (INH),
methotrexate (Rheumatrex), methyldopa ,and others.

11. Clove contains eugenol. Eugenol is the part of clove that
might slow blood clotting.
It may increase the bleeding with drugs such as
anticoagulants (heparin, warfarin ), and NSAIDS like
aspirin, diclofenac, ibuprofen, naprox, and others.
In children decrease the effect of anti-epileptic drugs as
phenytoin by damaging the liver.

12. GREEN TEA
High in tannin, do not take with
codeine
Large amounts may↑ effects and side
effects of theophylline
May ↓ effect of coronary vasodilator
drugs
May ↓ effects of warfarin
Green tea and aspirin should not be
mixed because they both prevent
platelets from clotting

13. – May ↑ bleeding with anticoagulants
– May ↑ effects of antibiotics
– ↑ efficacy of 5-fluorouracil and
vincristine
 May bleeding with anticoagulants (Anticoagulant /
Anti platelet drugs) interacts with CAPSICUM
Capsicum increase the theophylline absorption of the
body & also increases the side effects of theophylline
Medications for high blood pressure (ACE inhibitors)
interacts with CAPSICUM
 might increase the side effects of cocaine
including heart attack and death.

14. PEPPERMINT
The peppermint will decrease the metabolism of
cyclosporin (Neoral, Sandimmune)
Some medications that are changed by the liver include amitriptyline
(Elavil), haloperidol (Haldol), ondansetron (Zofran), propranolol
(Inderal),theophylline verapamil (Calan, Isoptin, others), and others.
Medications changed by the liver (Cytochrome P450 2C19 (CYP2C)
TAMARIND:
Tamarind (Tamarindus indica)
Aspirin Increased bioavailability of
aspirin52

15. TURMERIC:
 cs the activity of antacids (Lansoprazole …etc).
 Increase the blood-thinning effect with drug
like warfarin, aspirin(NSAIDs).
 Actively participate in the ce the blood glucose
level, when taken with anti diabetic drugs that
cause risk of lower blood sugar
(hypoglycaemia).
GRAPE JUICE:
Increase the oral bioavailability (human).
Gastrointestinal absorption and
bioavailability of statins like levostatin
Dicreases the total body metabolic rate.

16. Ginkgo:
May ↑ bleeding with anticoagulants
 May ↑ activity and side effects of
MAO inhibitors
 Increases blood pressure when
combined with a thiazide diuretic and
even caused coma
 Increases the digoxin plasma levels
GINSENG
(PANAX GINSENG):
Increases the AUC of digoxin
Decreased activity of opioids – clear
mechanism is unknown
Increased CNS side effects due to
additive effect of
MAO inhibitors
Phenelzine

17. VALERIAN:
 Valerian induces the sleep with antiseizure medications like barbiturates.
Ex. phenobarbitone, pentobarbitone
Prolongation of aesthesia with
anaesthetics
Produce sadation with barbiturates
&benzodiazepines
– Contraindicated with hepatotoxic
drugs and alcohol
– ↓ efficacy of Parkinson drugs
(L-Dopa)

18. Liquorice:
↓ efficacy, ↑ toxicity of diuretics
 ↓ efficacy, side effects of
digoxin
 AUC Corticosteroids like
prednisalone , methylprednisalone
Milk Thistle:
↓ hepatotoxicity of drugs
(haloperidol, phenytoin)
↓ kidney toxicity of
anesthetics

19. PHARMACIST’S ROLE
Advising
Monitoring
Reporting

20.  Health care professionals and pharmacists have to play an
important role in giving advisory knowledge on monitoring
concurrent use of herbal and conventional medicines and to
collect data for suspected herb-drug interactions.
We need to bring into lime light about the
herb – drug interactions

21. REFERENCES
 Baravkar A A, Sawant S D- “Herb-Drug-Interactions”
 Wheaton A G, Blanck H M- “Medicinal herb use in population




based survey”
Arthur M. Presser- “Herb-Drug Interactions”
Dorothea Dayley- “Drug-Herb-Nutrient Interactions”
Schuyler W.Lininger- “Drug-Herb-Vitamin Interactions
Natural medicines - Comprehensive database by
editors of Pharmacist’s letter and Prescriber’s
letter