1. 2
Drug Classes and Schedules

2. Drug Are Organized in Two Ways
Therapeutic classification
Pharmacologic classification

3. Therapeutic Classification of Drugs
Based on what the drug does clinically
Examples
Anticoagulants
Antidepressants
Antineoplastics

4. Table 2.1 Therapeutic Classification

5. Pharmacologic Classification of Drugs
Based on the drug's mechanism of action, or how the drug produces its effect
At molecular, tissue, or body-system level
More specific than therapeutic classification

6. Table 2.2 Pharmacologic Classification

7. Examples
Calcium-channel blockers
Diuretics
Adrenergic antagonists

8. “Prototype” Drug—Serves as Model for a Drug Class
Is well understood
Has known action and adverse effects
Is used to compare other drugs in the same pharmacologic class
May not be the most widely used drug in its class
Disagreements may exist over which drug should serve as prototype drug.

9. Newer Drugs in the Same Class
Newer drugs in the same class may have replaced the prototype drug's use because they:
Are more effective
Have a more favorable safety profile
Have longer duration of action

10. Most Drugs Have Three Names
Chemical
Generic
Trade

11. Drug Has One Chemical Name
Assigned using standard nomenclature established by International Union of Pure and Applied Chemistry (IUPAC)
Describes physical and chemical properties of drug
Sometimes helpful in predicting a substance's physical and chemical properties

12. Drug Has One Chemical Name
Complicated, difficult to remember and pronounce
Example: chemical name for diazepam: 7-chloro-1, 3-dihydro-1-methyl-5-phenyl-2H-1, 4-benzodiazepin-2-one

13. Chemical Group Name
Drugs are sometimes classified by a portion of their chemical structure:
Cephalosporins, phenothiazines, benzodiazepines
Chemical group names can become invaluable to a nursing student.

14. Generic Name Assigned by the U.S. Adopted Name Council
Less complicated and easier to remember

15. A Drug Has One Generic Name
Used by many organizations
Food and Drug Administration (FDA)
United States Pharmacopoeia
World Health Organization
Written in lower case
Example: diazepam

16. A Drug Has Several Trade Names
Assigned by company marketing the drug
Short, easy to remember
Also called proprietary, product, or brand name

17. A Drug Has Several Trade Names
Drug developer has exclusive rights to name and market a new drug for 17 years in the United States.
Trade name is capitalized.
Example: a trade name for diphenhydramine is Benadryl.

18. Trade Names
After 17 years, competing companies may sell a generic equivalent drug, sometimes using a different name, which the FDA must approve.

19. Trade Names
Trade names can be difficult because many drugs contain similar ingredients.
A combination drug contains more than one active ingredient.
The rule of thumb is that the active ingredients in a drug are described by their generic name, which is lowercase.

20. Table 2.3 Examples of Brand-Name Products Containing Popular Generic Substances

21. Rights Issues
A pharmaceutical company with exclusive rights to a drug often prices it very high.
When rights end, competing companies offer the generic form of the drug for less money.

22. Rights Issues
Depending on the state, a pharmacist may offer the generic form of a prescribed drug, or may only be allowed to dispense the exact form written in the prescription.
Drug companies lobby against easy substitution of generic drugs; consumer advocates lobby the opposite.

23. Generic vs. Brand-Name Drugs
It is difficult to tell if there is a difference in effect between two forms of a drug, even if dosage is the same.
Inert ingredients may be different.

24. Generic vs. Brand-Name Drugs
Key to comparison is bioavailability—the physiologic ability of the drug to reach its target cells and produce its effect.
Measuring how long a drug takes to exert its effect gives a crude measure of bioavailability.

25. Some States Have a Negative Formulary List
List of trade-name drugs that pharmacists may not dispense as generic-drug substitutes
Claim that there are differences in bioavailability between generic and trade-name drugs

26. Addiction and Dependence
The overwhelming feeling that drives a person to use a drug repeatedly
Dependence
A physiologic or psychologic need for a substance

27. Addiction and Dependence
Physical dependence
An altered physical condition caused by the adaptation of the nervous system to repeated drug use
When the drug is no longer available, the individual expresses physical signs of discomfort known as withdrawal.

28. Addiction and Dependence
Psychologically dependent
Little physical discomfort when drug is withdrawn, but intense compelling desire to continue use

29. Controlled Substances
Controlled substances are drugs that:
Are restricted by the Controlled Substances Act of 1970
Are frequently abused
Have a high potential for addiction or dependence
Have restricted use
Are placed into one of five schedules

30. Controlled Substance Act of 1970
Also known as Comprehensive Drug Abuse Prevention and Control Act
Restricts use of drugs with potential for abuse
Restricted drugs placed into the five schedules
Hospitals and pharmacies must maintain complete records of scheduled drugs.

31. Drug Enforcement Administration (DEA) Regulates Controlled Substance Act
Hospitals and pharmacies must register with DEA.
Must use assigned registration number to purchase scheduled drugs

32. Controlled Substances
Anyone convicted of unlawful manufacturing, distributing, and dispensing of controlled substances faces severe penalties.

33. Scheduled Drugs
Drugs that have a significant potential for abuse are placed into five categories called schedules.
Schedule I drugs have the highest abuse potential, Schedule V the lowest.

34. Table 2.4 Examples of Brand-Name Products Containing Popular Generic Substances

35. Schedule I Drugs
Restricted to situations of medical necessity, if allowed at all
Little or no therapeutic value; mostly used for research

36. Examples of Schedule I Drugs
Heroin
LSD
Methaqualone

37. Schedule II-V Drugs
May be dispersed only in cases where therapeutic value has been determined
Some Schedule V drugs may be dispersed without a prescription.

38. Not All Drugs with Abuse Potential Are Regulated
Tobacco, alcohol, and caffeine

39. Schedule II Drugs High abuse potential
High potential for physical and psychological dependence
Therapeutic use with prescription
Some drugs no longer used

40. Schedule II Drugs Have More Restrictions
Need special order form to obtain
Orders must be written.
Orders must be signed by health care provider.
Telephone orders to pharmacies are not permitted.
No refills are permitted; patient must see health care provider first.

41. Examples of Schedule II Drugs
Morphine
PCP
Cocaine
Methadone
Methamphetamine

42. Schedule III Drugs Moderate abuse potential
Moderate physical dependence
High potential for psychological dependence
Therapeutic use with prescription

43. Examples of Schedule III Drugs
Anabolic steroids
Codeine with aspirin or Tylenol
Hydrocodone with aspirin or Tylenol
Some barbiturates

44. Schedule IV Drugs Lower abuse potential
Lower potential for physical and psychological dependence
Therapeutic use with prescription

45. Examples of Schedule IV Drugs
Dextropropoxyphene
Pentazocine
Meprobamate
Diazepam
Alprazolam

46. Schedule V Drugs Lowest abuse potential
Lowest physical and psychological dependence
Therapeutic use without prescription
Examples:
OTC cough medicines with codeine

47. Teratogenic Drug Classification
Five categories of risk that a drug poses to a fetus in the case of a pregnant woman taking the drug
A, B, C, D, and X

48. Category A Drugs
Controlled studies in women fail to show a risk to the fetus, and the possibility of fetal harm appears unlikely.

49. Category B Drugs
Animal reproduction studies have not shown a fetal risk or adverse effect. Risks have not been confirmed in controlled studies in women.

50. Category C Drugs
Either studies in animals have revealed adverse effects on the fetus and there are no controlled studies in women or studies in women and animals are not available.

51. Category D Drugs
There is confirmation of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk—for example, in a life threatening situation.

52. Category X Drugs
Animal and human studies have shown fetal abnormalities.
The drug is contraindicated in women who are or may become pregnant.