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Basic and Clinical Pharmacology,
11th
Edition, Bertram G. Katzung,
Susan B. Masters,
Anthony J. Trevor, McGraw-Hill Medical (2009)
Pharmacology for Dentistry, Surender Singh, (
2007)
Pocket prescribe, 2010, Timothy R.J. Nicholson,
Ashan Gunarathne, Donald R.J. Singer
Drug Prescribing For Dentistry,Dental Clinical
Guidance, 3rd edition, Scottish Dental Clinical
Effectiveness Programme, 2016.
British National Formulary (BNF 68), 2014-2015
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Introduction
Prescribing Information
Drug Interactions
Prescribing For Specific Patient Groups
Prescription Writing
Adverse Reactions to Drugs
Medical Emergencies in Dental Practice
Pain Management
Bacterial, Fungal and Viral Infections
Mucosal Ulceration and Inflammation
Dry Mouth
Dental Caries
Pharmacology
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The science of drugs 
Greek: Pharmacos (drug) + logos (study)
The study of substances that interact with
living system through chemical processes,
especially by binding to regulatory molecules
and activating or inhibiting normal body
processes.
 Drug
A chemical substance of known structure,
other than a nutrient or an essential dietary
ingredient, when administered to a living
organism, produces a biological effect.
 Prodrug
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Pharmacodynamics deals with
physiological and biochemical effects
of drugs and their meachanism of
action at macromolecular ,
subcellular, organ, system level.
Pharmacokinetics may be defined as
the measurement and formal
interpretation of changes with time
of drug concentrations in one or
more different regions of the body in
relation to dosing ('what the body
does to the drug') . This
distinguishes it from
pharmacodynamics ('what the drug
does to the body‘
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A rational approach to this objective combines
the principles of pharmacokinetics with
pharmacodynamics to clarify the dose-effect
relationship.
Pharmacodynamics governs the concentrationeffect part of the interaction, whereas
pharmacokinetics deals with the doseconcentration part.
The pharmacokinetic processes of absorption,
distribution, and elimination determine how
rapidly and for how long the drug will appear at
the target organ. The pharmacodynamic concepts
of maximum response and sensitivity determine
the magnitude of the effect at a particular
concentration.
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oral (P.O)
sublingual (SL)
rectal
application to other epithelial surfaces (e.g. skin,
cornea, vagina and nasal mucosa)
inhalation
injection
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subcutaneous (SC)
intramuscular (IM)
intravenous (IV)
intrathecal
intravitreal
Local Routes
 The dosage forms applied locally to theskin
are powders, paste, lotions,
ointments,creams, plasters and jellies. They
are used for their antiseptic, antipruritic,
analgesic,local anaesthetic and other related
effects.
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The absorption of drug through the skin is
proportional to the surface area covered and
to their lipid solubility.
The dermis layer is freely permeable to many
fluids. Inflammatory and other related
conditions which increase the cutaneous
blood flow also enhance absorption of drugs
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The topical application is also used on the
mucous membranes i.e. nose, throat, eye,ear,
bronchi, rectum, urethra, vagina andrectum.
In case of mouth and pharynx, the drug is
used in the form of throat paints,
lozenges,gargles or mouth washes.
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The bronchial mucosa and lungs are treated
with inhalations, aerosols (in the formof fine
powder with the help of nebulizer) salbutamol
(ASTHALIN) inhaler.
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Inhalation is the route used for volatile and
gaseous anaesthetics ,the lung serving as the
route of both administration and elimination.
The rapid exchange resulting from the large
surface area and blood flow makes it possible
to achieve rapid adjustments of plasma
concentration.
Particles larger than 20 micron and the particles
impact in the mouth and throat. Smaller than 0.5
micron and they aren't retained
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Drugs used for their effects on the lung are also
given by inhalation, usually as an aerosol.
Glucocorticoids (beclometasone dipropionate)
and bronchodilators ( salbutamol are given in
this way to achieve high local concentrations in
the lung while minimising systemic side effects.
However, drugs given by inhalation in this way
are usually partly absorbed into the circulation,
and systemic side effects (tremor following
salbutamol) can occur.
Chemical modification of a drug may minimise
such absorption. For example, ipratropium, a
muscarinic receptor antagonist
Systemic Routes- Oral Route
 Enteric coated tablets: The drugs which are
destroyed by the gastric juices in the stomach,
arecoated with keratin, shellac and cellulose acid
phosphate. These substances are not dissolved
by the acid juice of the stomach, but are
dissolved in the intestinal juice (alkaline) only.
◦ Preventing gastric irritation and alteration of the drug in
the stomach.
◦ To get the desired concentration of the drug in intestine.
◦ To delay the absorption of the drug
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Time Release/Sustained Release Capsules: It
is a useful solid dosage form of drug, where
the particles of the drug dissolve at different
time intervals.
◦ Reduction in the frequency of administration of
drug
◦ Maintenance of therapeutic effect for longer time.
◦ To some extent decreased incidence of undesired
effects.
◦ Appropriate for drugs with short half lives (less
than 4 hours)
Sublingual Administration (SL)
 The highly lipid soluble and non-irritating
drugs. (nitroglycerine) in the form of tablets
or pellet is placed under the tongue, where
they rapidly dissolve and are absorbed
quickly in the general circulation.
 The advantages of this routes are:
 Rapid onset of action.
 The degradation and metabolism of the drugs in the
stomach and liver is avoided
Parenteral Route
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The advantages of parenteral routes are:
◦ Rapid action of drug.
◦ Can be employed in unconscious/uncooperative
patients.
◦ Drugs, which are modified by a limentary juices and liver
can be given by this route.
◦ Self medication is difficult.
◦ Chances of local injury at the site of injection
Drugs, which are not absorbed in small intestine
or irritate the stomach can be administered by
this route.
Disadvantages are:
◦ Less safe, more expensive.
◦ Inconvenient (painful) for the patient
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intravenous 30-60 seconds
intraosseous 30-60 seconds
endotracheal 2-3 minutes
inhalation 2-3 minutes
sublingual 3-5 minutes
intramuscular 10-20 minutes
subcutaneous 15-30 minutes
rectal 5-30 minutes
ingestion 30-90 minutes
transdermal (topical) variable (minutes to
hours)
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Solid Dosage forms : includes
capsules,granules, effervescent granules,
powders,tablets, insufflations, suppositories.
Semisolid/liquid dosage form : elixirs,
emulsions, gels, drops, solutions, syrups,
creams, enema.
Inhalation forms : aerosols,sprays.
Internal and external uses
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Receptor: The component of a cell or
organism that interacts with a drug and
initiates the chain of biochemical events
leading to the drug's observed effects.
It has an important practical consequences
for the development of drugs and for arriving
at therapeutic decisions in clinical practice.
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Potency refers to the concentration or dose
of a drug required to produce 50% of that
drug's maximal effect.
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Each drug requires a target within the body
(Receptor)
Binding of drugs to receptors could be:
◦ Reversible: Effect for short time (reversible bonding
forces)..most drugs.
◦ Irreversible: Effect is prolonged (Covalent bonding
forces)..Aspirin causes irreversible inhibition of PG
synthesis.
They act by antagonism or inhibition
 Cell surface Receptors
 Ion Channels
 Enzyme Inhibition
 Transport Inhibitors
 Nuclear Receptors