Clinical Pharmacy

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Clinical Pharmacy
Clinical pharmacy is a health science discipline in which pharmacists provide patient care that
optimizes medication therapy and promotes health, and disease prevention. Clinical Pharmacy
includes all the services performed by pharmacists practicing in hospitals, community pharmacies,
nursing homes, home-based care services, clinics and any other setting where medicines are
prescribed and used.
How clinical pharmacy differ from pharmacy? Or Clinical pharmacy vs pharmacy.
§ The discipline of pharmacy embraces the knowledge on synthesis, chemistry and
preparation of drugs
§ Clinical pharmacy is more oriented to the analysis of population needs with regards to
medicines, ways of administration, patterns of use and drugs effects on the patients.
§ The focus of attention moves from the drug to the single patient or population receiving
drugs.
Overall Goal of Clinical Pharmacy
The overall goal of clinical pharmacy activities is to promote the correct and appropriate use of
medicinal products and devices. These activities aim at:
§ Maximizing the clinical effect of medicines, i.e., using the most effective treatment for
each type of patient
§ Minimizing the risk of treatment-induced adverse events, i.e., monitoring the therapy
course and the patient's compliance with therapy
§ Minimizing the expenditures for pharmacological treatments born by the national health
systems and by the patients, i.e., trying to provide the best treatment alternative for the
greatest number of patients.
§ To assist the physician in doing a better job of prescribing and monitoring drug therapy for
the patient.
Introduction to clinical pharmacy RAYHAN
13
th
Batch
Pharmacy Clinical pharmacy

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§ To assist medical and para-medical staff and documenting medication incidents correctly.
§ To maximize the patient's compliance in drug use process.
How Clinical pharmacy activities may influence the correct use of medicines?
Clinical pharmacy activities may influence the correct use of medicines at three different levels-
before, during and after the prescription is written.
1. Before the prescription
 Clinical trials
 Formularies
 Drug information
 Clinical pharmacists have the potential to implement and influence drug-related policies,
i.e., making decisions on which drugs deserve to be marketed, which drugs should be
included in national and local formularies, which prescribing policies and treatment
guidelines should be implemented.
 Clinical pharmacists are also actively involved in clinical trials at different levels:
participating in ethical committees; study monitoring; dispensation and preparation of
investigational drugs.
2. During the prescription
 Clinical pharmacists can influence the attitudes and priorities of prescribers in their choice
of correct treatments.
 The clinical pharmacist monitors, detects and prevents harmful drug interaction, adverse
reactions ad medication errors through evaluation of prescriptions' profiles.
 The clinical pharmacist pays special attention to the dosage of drugs which need
therapeutic monitoring.
 Community pharmacists can also make prescription decisions directly, when over the
counter drugs are counselled.
3. After the prescription
 After the prescription is written, clinical pharmacists play a key role in communicating and
counselling patients.
 Pharmacists can improve patients' awareness of their treatments, monitor treatment
response, check and improve patients' compliance with their medications.
 As members of a multidisciplinary team, clinical pharmacists also provide integrated care
from 'hospital to community' and vice versa, assuring a continuity of information on risks
and benefits of drug therapy.

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Pharmacology and Clinical pharmacology
Pharmacology is the study of drugs (chemicals) that alterfunctions of living organisms. Or
Pharmacology is the study of drugs - how they interact with other molecules in the body and how
they affect the body. This field of study can be broken down into two smaller pieces:
pharmacokinetics and pharmacodynamics.
Clinical pharmacology is the use of drugs to prevent, diagnose, or treat signs, symptoms, and
disease processes. When preventionor cure is not a reasonable goal, relief of symptoms can
greatly improve quality of life and ability to function in activities of daily living.
Medications
Drugs given for therapeutic purposes are usually called medications.
Medications may be given for various reasons. In many instances, the goal of drug therapy is to
lessen disease processes rather than cure them. To meet this goal, drugsmay be given for local or
systemic effects.
Drugs with local effects, such as sunscreen lotions and local anesthetics, act mainly at the site of
application. Drug with systemic effects are taken into the body, circulated through the
bloodstream to their sites of action in various body tissues, and eventually eliminated from the
body. Most drugs are given for their systemic effects.
Drug names
Individual drugs may have several different names, there are two most commonly used are
1. The generic name is related to the chemical or official name and is independent of the
manufacturer. The generic name often indicates the drug group. Eg-penicillins, amoxicillin.
2. The trade name is designated and patented by the manufacturer. For example, amoxicillin is
manufactured by several pharmaceutical companies, some of which assign a specific trade name
(eg, Amoxil, Trimox). Drugs may be prescribed and dispensed by generic or trade name.
Testing and Clinical Trials
The testing process begins with animal studies to determinepotential uses and effects. The next
step involves FDA reviewof the data obtained in the animal studies. The drug then undergoes
clinical trials in humans.
Clinical trials are research studies that test how well new medical approaches work in people.
Clinical trials use a randomized, controlled experimental design that involves selection of subjects
according to established criteria, random assignment of subjects to experimental groups, and
administration of the test drug to one group and a control substance to another group.

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Pharmacokinetics and pharmacodynamics
Pharmacokinetics involves drug movement through the body (ie, “what the body does to the
drug”) to reach sites of action, metabolism, and excretion. Specific processes are absorption,
distribution, metabolism (biotransformation), and excretion. Overall, these processes largely
determine serum drug levels, onset, peak and duration of drug actions, drug half-life, therapeutic
and adverse drug effects, and other important aspects of drug therapy.
Pharmacodynamics involves drug actions on target cells and the resulting alterations in cellular
biochemical reactions and functions (ie, “what the drug does to the body”). As previously stated,
all drug actions occur at the cellular level.
Entry and movement of drug molecules through the body
Drugs undergo four stages within the body: absorption, distribution, metabolism, and excretion.
After a drug is administered, it is absorbed into the bloodstream. The circulatory system then
distributes the drug throughout the body. After the drug has had its effect, then the drug is
metabolized by the body. The drug is then excreted, primarily through urine or feces.
Absorption
Absorption is the process that occurs from the time a drug entersthe body to the time it enters the
bloodstream to be circulated.Onset of drug action is largely determined by the rate of absorption;
intensity is determined by the extent of absorption.
Factors affect the rate and extent of drug absorption, including
 dosage form,
 route of administration,
 blood flow to the site of administration,
 GI function,
 the presence of food or other drugs, and other variables.

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Dosage Form: Dosage Form (DF) is defined as the physical form of a dose of a chemical
compound used as a drug or medication intended for administration or consumption. Common
dosage forms include tablet, or capsule, syrup, aerosol or inhaler, liquid injection, pure powder or
solid crystal.
Oral drugs
Oral drugs must be swallowed, dissolved in gastricfluid, and delivered to the small intestine (which
has a large surface area for absorption of nutrients and drugs) before they are absorbed. Liquid
medications are absorbed faster than tablets or capsules because they need not be dissolved.
Some patients have difficulty swallowing tablets or capsules; some dislike the taste. In these
cases, crushing of medication for powdered delivery (to be mixed with food or beverages) should
be considered. But not all medications are suitable for crushing.
Drugs that should not be crushed
1. Sustained-release tablets, which can be composed of multiple layers for different drug release
times, as can beads within capsules. Some of the more common prefixes or suffixes for sustained-
release, controlled-release, controlled-delivery, extended-release, prolonged-release, slow-release
products include: 12-hour, 24-hour, CC, CD, CR, ER, LA, Retard, SA, Slo-, SR, XL, XR, or XT.
2. Enteric-coated tablets, which are formulated because certain drugs can be irritating to the
stomach or are degraded by stomach acid. By enteric-coating tablets or capsule beads, the drug’s
release can be delayed until it reaches the small intestine. Prefixes include EN- and EC-.
Advantages & Dis Advantages Sustained-release tablets

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Drug transport pathways
Drug molecules cross cell membranes to move into and out of body cells by directly penetrating
the lipid layer, diffusing through open or gated channels,or attaching to carrier proteins.
Plasma proteins, mainly albumin (A), act as carriers for drug molecules (D). Bound drug (A–D)
stays in bloodstream and is pharmacologically inactive. Free drug (D) can leave the bloodstream
and act on body cells.
“The liver is the principal organ of drug”- explain.
The liver is the principal site of drug metabolism. Drugs can be metabolized by oxidation,
reduction, hydrolysis, hydration, conjugation, condensation, or isomerization; whatever the
process, the goal is to make the drug easier to excrete. The enzymes involved in metabolism are
present in many tissues but generally are more concentrated in the liver. Other tissues that display
considerable activity include the gastrointestinal tract, the lungs, the skin, and the kidneys.
Following oral administration, many drugs (eg, isoproterenol, meperidine, pentazocine, morphine)
are absorbed intact from the small intestine and transported first via the portal system to the liver,
where they undergo extensive metabolism. This process has been called a first-pass effect. Some
orally administered drugs (eg, clonazepam, chlorpromazine) are more extensively metabolized in
the intestine than in the liver. Thus, intestinal metabolism may contribute to the overall first-pass
effect. First-pass effects may so greatly limit the bioavailability of orally administered drugs that
alternative routes of administration must be used to achieve therapeutically effective blood levels.

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Pharmacodynamic Variables
§ Maximum Effect аll pharmacologic responses must have a maximum effect (Emax). No
matter how high the drug concentration goes, a point will be reached beyond which no further
increment in response is achieved.
§ Sensitivity the sensitivity of the target organ to drug concentration is reflected by the
concentration required to produce 50% of maximum effect, the EC50. Failure of response due
to diminished sensitivity to the drug can be detected by measuring—in a patient who is not
getting better—drug concentrations that are usually associated with therapeutic response. This
may be a result of abnormal physiology—eg, hyperkalemia diminishes responsiveness to
digoxin—or drug antagonism—eg, calcium channel blockers impair the inotropic response to
digoxin.
§ Drug Clearance is the single most important factor determining drug concentrations.
Clearance is readily estimated from the dosing rate and mean steady-state concentration. Blood
samples should be appropriately timed to estimate steady-state concentration.
§ Serum half-life, also called elimination half-life, is the time required for the serum
concentration of a drug to decrease by 50%. It is determined primarily by the drug’s rates of
metabolism and excretion. A drug with a short half-life requires more frequent administration
than one with a long half-life.
§ Вioavailability is defined as the fraction of a given drug dose that reaches the circulation in
unchanged form and becomes available for systemic distribution. The larger the presystemic
elimination, the smaller is the bioavailability of an orally administered drug.
Receptors
Сеll membrane contains receptors for physiologic substances such as hormones (H) and
neurotransmitters (NT). These substances stimulate or inhibit cellular function. Drug molecules
(Da and Db) also interact with receptors to stimulate or inhibit cellular function.

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Agonists : Agonists are drugs that produce effects similar to those produced by naturally occurring
hormones, neurotransmitters, and other substances. Agonists may accelerate or slow normal
cellular processes, depending on the type of receptor activated. For example, epinephrine-like
drugs act on the heart to increase the heart rate, and acetylcholine-like drugs act on the heart to
slow the heart rate; both are agonists.
Antagonists: Antagonists are drugs that inhibit cell function by occupying receptor sites. This
prevents natural body substances or other drugs from occupying the receptor sites and activating
cell functions. Once drug action occurs, drug molecules may detach from receptor molecules (ie,
the chemical binding is reversible), return to the bloodstream, and circulate to the liver for
metabolism and the kidneys for excretion.
Drug tolerance and cross-tolerance
Drug tolerance occurs when the body becomes accustomed to a particular drug over time so that
larger doses must be given to produce the same effects. Tolerance may be acquired to the
pharmacologic action of many drugs, especially opioid analgesics, alcohol, and other CNS
depressants. Tolerance to pharmacologically related drugs is called cross-tolerance. For example,
a person who regularly drinks large amounts of alcohol becomes able to ingest even larger amounts
before becoming intoxicated—this is tolerance to alcohol. If the person is then given sedative-type
drugs or a general anesthetic, larger-than-usual doses are required to produce a pharmacologic
effect—this is cross-tolerance. Tolerance and cross-tolerance are usually attributed to activation
of drug-metabolizing enzymes in the liver, which accelerates drug metabolism and excretion. They
also are attributed to decreased sensitivity or numbers of receptor sites.
Adverse effects & side effect of drugs
Adverse effects: Тhe term adverse effects refers to any undesired responses to drug after
administration.
Side effect: any effect of a drug, chemical, or other medicine that is in addition to its
intended effect, especially an effect that is harmful or unpleasant is called side effects.
Some adverse effects occur with usual therapeutic doses of drugs (often called side effects); others
are more likely to occur and to be more severe with high doses.
 CNS effects may result from CNS stimulation (eg, agitation,confusion, delirium,
disorientation, hallucinations,psychosis, seizures) or CNS depression (dizziness,
drowsiness, impaired level of consciousness,sedation, coma, impaired respiration and
circulation).

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 Gastrointestinal effects (anorexia, nausea, vomiting, constipation, diarrhea)
 Hematologic effects (blood coagulation disorders, bleeding disorders, bone marrow
depression, anemias, leukopenia, agranulocytosis, thrombocytopenia)
 Hepatotoxicity (hepatitis, liver dysfunction or failure, biliary tract inflammation or
obstruction)
 Nephrotoxicity (nephritis, renal insufficiency or failure)
 Hypersensitivity or allergy
 Drug fever
 Idiosyncrasy refers to an unexpected reaction to a drug that occurs the first time it is given.
 Drug dependence
 Carcinogenicity is the ability of a substance to cause cancer.
 Teratogenicity is the ability of a substance to cause abnormal fetal development when
taken by pregnant women.
What is clinical Pharmacist?
Clinical pharmacists interact, coordinate, and work directly with physicians, other health
professionals, and patients to ensure that the medications prescribed for patients contribute to the
best possible health outcomes. Clinical pharmacists practice in many different health care
environments: hospitals and their affiliated outpatient clinics, emergency departments, community
pharmacies, physicians’ offices, community-based clinics, nursing homes, and managed care
organizations.
Role or functions of clinical Pharmacist?
1. Assuring safe, accurate, rational and cost-effective use of medications
2. Engage in collaborative practice with other healthcare practitioners for the purpose of
improving care and conserving resources

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3. Make patient-focused transitions into and out of acute care practice settings, ambulatory
care or alternative site settings with the patient’s best interest in mind
4. Possess in-depth knowledge of medications that is integrated with a foundational
understanding of the biomedical, pharmaceutical, socio-behavioral, and clinical sciences.
5. To achieve desired therapeutic goals, the clinical pharmacist applies evidence-based
therapeutic guidelines, evolving sciences, emerging technologies, and relevant legal,
ethical, social, cultural, economic and professional principles
6. Assume responsibility and accountability for managing medication therapy in direct patient
care settings, whether practicing independently or in consultation/collaboration with other
health care professionals
7. Within the system of health care, clinical pharmacists are experts in the therapeutic use of
medications
8. Routinely provide medication therapy evaluations and recommendations to patients and
health care professionals
9. Clinical pharmacist researchers generate, disseminate, and apply new knowledge that
contributes to improved health and quality of life