Drug interaction & Classification & Herbal drug /Food interaction

1. SEM-6 Herbal Drug
Formulation
UNIT 2

2. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Q- Define Drug interaction and
classify them?
Russell Martin Page 2
Drug interaction is a reaction
between two or more drugs or
between a drug and a food,
beverage or supplement inside
the body.
A drug interaction may be less
effective, increased activity or
cause unwanted side effects.

3. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Types of
Drug
interaction
Drug-
Drug
interactio
n
Drug-
Food
Interactio
n
Drug-
Disease
interaction
Russell Martin Page 3

4. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Drug- Drug Interaction
Russell Martin Page 4
These are the most common type of
interaction. More the medication
administered, greater is the chance of
drug interacting with each other. One
drug may be potentiate the activity of
another or inhibit its activity or serious
unexpected side effects may occur.
Ex- Vicodin a pain killer when taken
along with sedating antihistaminine drug,
Benadryl produce an additive effect of
drowsiness.

5. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Drug – Food interaction
Russell Martin Page 5
This is another type of drug interaction
where drugs interact with food/
beverages and can produce various side
effects.
Ex- Grape juice reduces the enzyme
activity in liver which are responsible for
metabolizing drugs thus resulting in
increased blood levels of certain drugs
such as cholesterol lowering drugs
(statins), this leads to toxic effects of the
drugs such as muscle pain and muscle
injury.

6. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Drug- Disease interaction
Russell Martin Page 6
Sometimes drugs also interact
with certain disease where the
disease alter the way a drug
works.
Ex- Oral decongestants like
pseudoephedrine, phenylephrine
may increase the blood pressure
& can be dangerous in patients
having hypertension.

7. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Mechanism of Drug Interaction
Russell Martin Page 7

8. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Q-Define Pharmacodynamics
Russell Martin Page 8
This occurs when two or more
drugs administered together act
at the similar receptor sited
leading to enhancement
(additive or synergistic)effect is
decreased (antagonist).
Ex-Chlorpromazine given to
prevent nausea and vomiting
interacts with antipsychotic
medication like haloperidol and
produce serious and possible
fatal irregular cardiac rhythm.

9. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Q Define Pharmacokinetics with
example
Russell Martin Page 9
This occurs when drug interacts during
the process of absorption, distribution,
metabolism and excretion.
Absorption interactions
Some drugs alter the absorption of
another drug for example calcium can
bind with some drugs ike tetracycline
and HIV drug dolutegravir and blocks its
absorption. Hence such drugs should not
be taken along with milk and antacids.
Note :- Pharmacodynamics interactions
occur due to the pharmacological effect
of the drugs.

10. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Distribution interaction
Russell Martin Page
10
One or more drugs can compete with each
other for plasma protein binding sites
resulting in displacement of one drug
thereby increasing its blood levels and
toxicity.
Ex- fenofibric acid (chlosterol lowering
agent) and warfarin (blood thinner) when
administered together compete for the
protein binding sited leading to
displacement and increased blood levelsof
warfarin thus resulting in bleeding.

11. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Metabolism interaction
Russell Martin Page
11
Enzyme in the liver such as cytochromes
is responsible for metabolising drug and
eliminating them from the body. Some
drugs may alter the enzyme levels or its
activity resulting in fast or slow
metabolism of drugs.
Ex- Diltiazem (antihypertensive) inhibit
the cytochrome enzyme responsible for
metabolizing simvastatin
(hypercholestremic) & elevates it’s blood
levels resulting in severe liver and
muscle side effects.

12. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Excretion interaction
Some non- steroidal anti-
Russell Martin Page
12
inflammatory drugs (NSAID,s)
like indomethacin may lower
the kidney function and reduce
the excretion of lithium, a drug
used for bipolar disorder. In
such cases dose adjustment is
required.

13. Unit-II Herbal Drug & Herb-Food Interaction Sem-6
Herb-Drug /Food Interactions
Russell Martin Page
13
Even though Herbal medicines are obtained
from natural sources their active ingredients
are potent chemicals which can give rise to
herb drug or herb food interactions.
Herbal supplement and nutraceuticals are
been purchased over the counter (OTC) and
may be labeled as “All Naturals” but that
does not mean they are always safe.
Herbal supplements (like Amway products)
are not subject to review to FDA and their
use can be often risky when taken along
with other drugs or foods.