Types of pharmacy practice areas

Pharmacists practice in a variety of areas including retail, hospitals, clinics, nursing homes, drug industry, and regulatory agencies. Pharmacists can specialize in various areas of practice including but not limited to: hematology/oncology, infectious diseases, ambulatory care, nutrition support, drug information, critical care, pediatrics, etc.

Community pharmacy

A pharmacy (commonly the chemist in Australia, New Zealand and the UK; or drugstore in North America; retail pharmacy in industry terminology; or Apothecary, historically) is the place where most pharmacists practice the profession of pharmacy. It is the community pharmacy where the dichotomy of the profession exists—health professionals who are also retailers.

Community pharmacies usually consist of a retail storefront with a dispensary where medications are stored and dispensed. The dispensary is subject to pharmacy legislation; with requirements for storage conditions, compulsory texts, equipment, etc., specified in legislation. Where it was once the case that pharmacists stayed within the dispensary compounding/dispensing medications; there has been an increasing trend towards the use of trained pharmacy technicians while the pharmacist spends more time communicating with patients.

All pharmacies are required to have a pharmacist on-duty at all times when open. In many jurisdictions, it is also a requirement that the owner of a pharmacy must be a registered pharmacist (R.Ph.). This latter requirement has been revoked in many jurisdictions, such that many retailers (including supermarkets and mass merchandisers) now include a pharmacy as a department of their store.

Likewise, many pharmacies are now rather grocery store-like in their design. In addition to medicines and prescriptions, many now sell a diverse arrangement of additional household items such as cosmetics, shampoo, office supplies, confectionary, and snack foods.

Also, retail pharmacists usually make more money than their clinical counterparts.

Chemist

A chemist is a scientist trained in the science of chemistry. Chemists study the composition of matter and its properties such as density, acidity, size and shape. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, reaction rates, and other chemical properties.

Chemists use this knowledge to learn the composition, and properties of unfamiliar substances, as well as to reproduce and synthesize large quantities of useful naturally occurring substances and create new artificial substances and useful processes. Chemists may specialize in any number of subdisciplines of chemistry. Materials scientists and metallurgists share much of the same education and skills with chemists. Chemical engineers are concerned with the physical processes necessary to carry out industrial reactions (heating, cooling, mixing, diffusion etc) and to separate and purify the products, and work with industrial chemists on the development of new processes.

Apothecary

Interior of an apothecary's shop. Illustration from Illustrated History of Furniture, From the Earliest to the Present Time from 1893 by Litchfield, Frederick, (1850-1930)

A historical re-enactor portraying a 19th century apothecary in Old Salem, North Carolina, USA.

Apothecary (pronounced /ə΄pɒθikəri/) is a historical name for a medical professional who formulates and dispenses materia medica to physicians, surgeons and patients — a role now served by a pharmacist (or, especially in British English, a chemist or dispensing chemist).

In addition to pharmacy responsibilities, the apothecary offered general medical advice and a range of services that are now performed solely by other specialist practitioners, such as surgery and midwifery. Apothecaries often operated through a retail shop which, in addition to ingredients for medicines, sold tobacco and patent medicines.

In its investigation of herbal and chemical ingredients, the work of the apothecary may be regarded as a precursor of the modern sciences of chemistry and pharmacology, prior to the formulation of the scientific method.

According to Sharif Kaf al-Ghazal, the first apothecary shops were founded during the Middle Ages in Baghdad. By the end of the 14th century, Geoffrey Chaucer (1342-1400) was mentioning an English apothecary in the Canterbury Tales, specifically "The Nun's Priest's Tale" as Pertelote speaks to Chauntecleer (lines 181-184):

. . . for ye shal nat tarie,
Though in this toun is noon apothecarie,
I shal myself to herbes techen yow,
That shul been for youre hele and for youre prow.

. . . since you shouldn't tarry,
And in this town there's no apothecary,
I will myself go find some herbs for you
That will be good for health and pecker too.

By the 15th century, the apothecary gained the status of a skilled practitioner, but by the end of the 19th century, the medical professions had taken on their current institutional form, with defined roles for physicians and surgeons, and the role of the apothecary was more narrowly conceived as that of pharmacist (dispensing chemist in British English).

One famous mention of an apothecary appears in William Shakespeare's play Romeo and Juliet, in which a poor apothecary sells Romeo an elixir of death with which Romeo commits suicide.

In England, the apothecaries merited their own livery company, the Worshipful Society of Apothecaries, founded in 1617. Elizabeth Garrett Anderson became the first woman to gain a medical qualification in Britain when she passed the Society's examination in 1865.

Apothecaries used their own measurement system, the apothecaries' system, to provide precise weighing of small quantities. Apothecaries also were known to accept special requests for viles and poisons. This meaning of the term "apothecary" has not passed into archaic oblivion, as in William Faulkner's still widely read 1930 story "A Rose for Emily" the main character, Miss Emily Grierson, goes to an "apothecary" and buys arsenic, ostensibly to kill a rat (which turns out later to have been her Yankee boyfriend who had apparently become bent on jilting her).

Words which are cognate to apothecary have the meaning of "pharmacist" or "dispensing chemist" in certain modern languages. In Swedish, for example, a pharmacy is ett apotek. The pharmacist (dispensing chemist) is called en apotekare.

Compounding

Compounding (also pharmaceutical compounding and compounding pharmacy) is the mixing of drugs by a pharmacist, physician, or veterinarian to fit the unique needs of a patient. This may be done for medically necessary reasons, such as to change the form of the medication from a solid pill to a liquid, to avoid a non-essential ingredient that the patient is allergic to, or to obtain the exact dose needed. It may also be done for voluntary reasons, such as adding favorite flavors to a medication.

History

Before mass production of medications became normal, compounding was a routine activity among pharmacists. Community pharmacists who have experience with compounding techniques are now less common.

The art of pharmaceutical compounding has ancient roots. Hunter-gatherer societies had some knowledge of the medicinal properties of the animals, plants, molds, fungus and bacteria as well as inorganic minerals within their environment. Ancient civilizations utilized pharmaceutical compounding for religion, grooming, keeping the healthy well, treating the ill and preparing the dead. These ancient compounders produced the first oils from plants and animals. They discovered poisons and the antidotes. They made ointments for wounded patients as well as perfumes for customers.

The earliest druggists were familiar with various natural substances and their uses. These drug artisans compounded a variety of preparations such as medications, dyes, incense, perfumes, ceremonial compounds, preservatives and cosmetics. Drug compounders seeking gold and the fountain of youth drove the Alchemy movement. Alchemy eventually contributed to the creation of modern pharmacy and the principles of pharmacy compounding. In the medieval Islamic world in particular, Muslim pharmacists and chemists developed advanced methods of compounding drugs. The first drugstores were opened by Muslim pharmacists in Baghdad in 754, while the first apothecary shops were also founded by Muslim practitioners.

The modern age of pharmacy compounding began in the 19th century with the isolation of various compounds from coal tar for the purpose of producing synthetic dyes. From this one natural product came the earliest antibacterial sulfa drugs, phenolic compounds made famous by Joseph Lister, and plastics.

During the 1800s, pharmacists specialized in the raising, preparation and compounding of crude drugs. Crude drugs, like opium, are from natural sources and usually contain multiple chemical compounds. The compounding pharmacist often extracted these crude drugs using water or alcohol to form extracts, concoctions and decoctions.

Pharmacists began isolating and identifying the active ingredients contained within these crude drug concoctions. Using fractionation or recrystallization, the compounding pharmacist would separate the active ingredients, like morphine, and use it in place of the crude drug. During this time modern medicine began.

With the isolation of medications from the “raw materials” or crude drugs came the birth of the modern pharmaceutical company. Pharmacists were trained to compound the preparations made by the drug companies, but they were unable to do it efficiently on a small scale. So economies of scale, not lack of skill or knowledge, produced a market for the modern pharmaceutical drug companies (Pharma).

With the turn of the 20th century came greater government regulation of the practice of medicine. These new regulations forced the drug companies to prove that any new medication they brought to market was safe. With the discovery of penicillin, modern marketing techniques and brand promotion, the drug manufacturing industry came of age. Pharmacists continued to compound most prescriptions until the early 1950s when the majority of dispensed drugs came directly from the large pharmaceutical companies

Pharmaceutics

Pharmaceutics is the discipline of pharmacy that deals with all facets of the process of turning a new chemical entity (NCE) into a medication able to be safely and effectively used by patients in the community. Pharmaceutics is the science of dosage form design. There are many chemicals with known pharmacological properties but a raw chemical is of no use to a patient. Pharmaceutics deals with the formulation of a pure drug substance into a dosage form. Branches of pharmaceutics include:

• Pharmacokinetics
• Pharmacodynamics
• Pharmacogenomics
• Pharmaceutical formulation
• Pharmaceutical technology

The Pharmaceutical sciences are a group of interdisciplinary areas of study involved with the design, action, delivery, disposition, and use of drugs. This field draws on many areas of the basic and applied sciences, such as chemistry (organic, inorganic, physical, biochemistry and analytical), biology (anatomy and physiology, biochemistry, cell biology, and molecular biology), mathematics, physics, and chemical engineering, and applies their principles to the study of drugs.

DRUG DOSAGE

Dose’ is the appropriate amount of a drug needed to produce a certain degree of response in a patient. Accordingly, dose of a drug has to be qualified in terms of the chosen response, e.g. the analgesic dose of aspirin for headache is 0.3-0.6g, while it’s anti-inflammatory dose for rheumatoid arthritis is 3-6g per day. Similarly there could be prophylactic dose, a therapeutic dose or a toxic dose of the same drug.

The dose of a drug is governed by its inherent potency, i.e. the concentration at which it should be present at the target site, and its pharmacokinetic characteristics. In addition, it is modified by a number of factors. However, different strategies are adopted for individualizing drug dosage.

1. Standard dose. The same dose is appropriate for most patients –individual variations are minor or the drug has a wide safety margin so that enough can be given to cover them, e.g. oral contraceptives, penicillin, chloroquine, mebendazole, amantadine.

2. Regulated dose. The drug modifies a finely regulated body function which can be easily measured. The dosage is accurately adjusted by repeated measurement of the affected physiological parameter, e.g. antihypertensives, hypoglycaemics, anticoagulants, diuretics, general anaesthetics.

3. Target level dose. The response is not easily measurable but has been demonstrated to be obtained at a certain range of drug concentration in plasma. An empirical dose aimed at attaining the target level is given in the beginning and adjustments are made later by actual monitoring of plasma concentrations. When facilities for drug level monitoring are not available, crude adjustments are made by observing the patient at relatively long intervals, e.g. antidepressants, antiepileptics, digoxin, lithium,theophylline.

4. Titrated dose. The dose needed to produce maximal therapeutic effect cannot be given because of intolerable adverse effects. Optimal dose is arrived at by titrating it with an acceptable level of adverse effect. Low initial dose and upward titration (in most non-critical situations) or high initial dose and downward titration (in critical situations) can be practised. Often a compromise between submaximal therapeutic effect but tolerable side effects can be struck, e.g. anticancer drugs, corticosteroids, levodopa.

ADVERSE DRUG EFFECTS

Adverse effect is ‘any undesirable or unintended consequence of drug administration. It is a broad term, includes all kinds of noxious effect –trivial, serious or even fatal.

For the purposes of detecting and quantifying only those adverse effects of a drug which are of some import and occur in ordinary therapeutic setting, the term ADVERSE DRUG REACTION has been defined as ‘any noxious change which is suspected to be due to a drug, occurs at doses normally used in man, requires treatment or decrease in dose or indicates caution in the future use of the same drug’. This definition excludes trivial or expected side effects and poisonings or overdose.

All drugs are capable of producing adverse effects and whenever a drug is given a risk is taken. The magnitude of risk has to be considered along with magnitude of expected therapeutic benefit in deciding whether to use or not to use a particular drug in a given patient, e.g. even risk of bone marrow depression may be justified in treating cancer while mild drowsiness caused by an antihistaminic in treating common cold may be unacceptable.

Adverse effects may develop promptly or only after prolonged medication or even after stoppage of the drug. Adverse effects are not rare; an incidence of 10-25% has been documented in different clinical settings. They are more common with multiple drug therapy and in the elderly. Adverse effects have been classified in many ways. One may divide them into:

Predictable (Type A) reactions. These are based on pharmacological properties of the drug; include side effects, toxic effects and consequences of drug withdrawal. They are more common, dose related and mostly preventable.

Unpredictable (Type B) reactions. These are based on peculiarities of the patient and not on drug’s known actions; include allergy and idiosyncrasy. They are less common, often non-dose related, generally more serious and require withdrawal of the drug. Some of these reactions can be predicted and prevented if their genetic basis is known and suitable test to characterize the individual’s phenotype is performed.

Severity of adverse drug reactions has been graded as:

Minor: No therapy, antidote or prolongation of hospitalization required.

Moderate: Requires change in drug therapy, specific treatment or prolongs

hospital stay by at least one day.

Severe: Potentially life threatening, causes permanent damage or requires

intensive medical treatment.

Lethal: Directly or indirectly contributes to death of the patient.

Prevention of adverse effects to drugs.

Adverse drug effects can be minimized but not altogether eliminated by observing the following practices:

1. Avoid all inappropriate use of drugs in the context of patient’s clinical condition.

2. Use appropriate dose, route and frequency of drug administration based on patient’s specific variables.

3. Elicit and take into consideration previous history of drug reactions.

4. Elicit history of allergic diseases and exercise caution (drug allergy is more common in patients with allergic diseases).

5. Rule out possibility of drug interactions when more than one drug is prescribed.

6. Adopt correct drug administration technique (e.g. intravenous injection of aminophylline must be slow).

7. Carry out appropriate laboratory monitoring (e.g. prothrombin time with warfarin, serum drug levels with lithium).

1. SIDE EFFECTS

These are unwanted but often unavoidable pharmacodynamic effects that occur at therapeutic doses. They can be predicted from the pharmacological profile of a drug and are known to occur in a given percentage of drug recipients. Reduction in dose generally ameliorates the symptoms.

A side effect may be based on the same action as the therapeutic effect, e. g. atropine is used in preanaesthetic medication for its antisecretory action –produces dryness of mouth as a side effect; acetazolamide acts as a diuretic by promoting bicarbonate excretion –acidosis occurs as a side effect.

Side effect may also be based on a different facet of action, e. g. promethazine produces sedation which is unrelated to its antiallergic action; estrogens cause nausea which is unrelated to their antiovulatory action.

Many drugs have been developed from observation of side effects, e. g. sulfonamides used as antibacterial were found to produce hypoglycaemia and acidosis as side effects which directed research resulting in the development of hypoglycaemic sulfonylureas and carbonic anhydrase inhibitor –acetazolamide.

2. SECONDARY EFFECTS

These are indirect consequences of a primary action of the drug, e.g. suppression of bacterial flora by tetracyclines paves the way for superinfections; corticosteroids weaken host defence mechanisms so that latent tuberculosis gets activated.

3. TOXIC EFFECTS

These are the result of excessive pharmacological action of the drug due to overdosage or prolonged use. Overdosage may be absolute (accidental, homicidal, suicidal) or relative (i.e. usual dose of gentamicin in presence of renal failure). The effects are predictable and dose related. They result from functional alteration (high dose of atropine causing delirium) or drug induced tissue damage (hepatic necrosis from paracetamol overdosage). The CNS, CVS, kidney, liver, lung, skin and blood forming organs are most commonly involved in drug toxicity.

4. INTOLERANCE

It is the appearance of characteristic toxic effects of a drug in an individual at therapeutic doses. It is the converse of tolerance and indicates a low threshold of the individual to the action of a drug.

· A single dose of triflupromazine induces muscular dystonias in some individuals, specially children.

· Only few doses of carbamazepine may cause ataxia in some people.

· One tablet of chloroquine may cause vomiting and abdominal pain in a occasional patient.

5. IDIOSYNCRASY

It is genetically determined abnormal reactivity to a chemical. Certain adverse effects of some drugs are largely restricted to individuals with a particular genotype. In addition, certain uncharacteristic or bizarre drug effects due to peculiarities of an individual (for which no definite genotype has been described) are included among idiosyncratic reactions, e.g.:

· Barbiturates cause excitement and mental confusion in some individuals.

· Quinine /quinidine cause cramps, diarrhea, purpura, asthma, vascular collapse in some patients.

6. DRUG ALLERGY

It is an immunologically mediated reaction producing stereotype symptoms which are unrelated to the pharmacodynamic profile of the drug and are largely independent of dosage. This is also called drug hypersensitivity; but does not refer to increased response which is called supersensitivity.

Allergic reactions occur only in a small proportion of the population exposed to the drug and cannot be produced in other individuals at any dose. Chemically related drugs often show cross sensitivity. One drug can produce different types of allergic reactions in different individuals, while widely different drugs can produce the same reaction. The course of drug allergy is variable; an individual previously sensitive to a drug may subsequently tolerate it without a reaction and vice versa.

Keys to exercises for advanced students

Ex. I.

1. analgesics

2. diuretics

3. stimulants

4. anti-inflammatory

5. narcotics

6. anti-emetics

7. aspirin

8. anticoagulants

9. sedatives

10. tranquillizers

11.laxatives

12. decongestants

13. miracle drugs

14. insulin

15. digitalis

Ex. II.

promote sleep

be absorbed into the blood stream

stimulate the production of hormones

interfere with other drugs

suppress nausea

have an inhibitory effect

impair the ability to drive

dilate the blood vessels

cause side effects

reduce the heart rate

alleviate pain

soothe inflammation

replace abnormal losses of body fluids

Ex. III.

1. ointment

2. cream

3. solution

4. plasters

5. glucagen injection

6. vaccine

7. lozenges

8. gauze swabs

9. tape

10. soap

11. soap

12. cotton wool

13. insulin

14. crystals

Ex. IV.

1. rub (put)

2. take

3. spray (put)

4. apply

5. chew

6. insert (put)

7. put

8. stick (apply)

9. wear

10. carry (take)

11. lay, dissolve

12. sip

13. clean, leave

14. dissolve, inhale

15. dip

16. continue

Ex. V.

1. c 2. a 3. b 4. b 5. c

6. c 7. a 8. d 9. b 10. a 11. a

Ex. VI.

1. gentamicin, erythromycin

2. co-trimoxazole, erythromycin

3. ampicillin

4. ampicillin, co-trimoxazole

5. benzylpenicillin

6. gentamicin, benzylpenicillin

7. tetracycline

8. phenoxymethylpenicillin, benzylpenicillin

9. tetracycline

10. erythromycin

CONTENTS

AT THE CHEMIST’S (TEXT)

TOPIC VOCABULARY

ADDITIONAL VOCABULARY

EXERCISES

TEXTS FOR ADDITIONAL READING

EXERCISES FOR ADVANCED STUDENTS

DIALOGUES

INSTRUCTIONS

TEXTS FOR GETTING INFORMATION