Week 1 Flashcards
1
Q
What needs to be known to administer drugs safely?
A
- Pharmacodynamics: how the drug works
- Pharmacokinetics: how our body affects the drug
- Usual dose, frequency, and route of drug administration
- Pharmacological effects and indications
- Adverse drug effects and contraindications
- Drug interactions
2
Q
What is a medicine?
A
- A drug mixed in a formulation to allow it to be administered
3
Q
What are useful drug characteristics?
A
- Potency - amount of chemical required to produce an effect
- Selectivity (biological) - narrowness of a drug’s range of actions on particular receptors, cellular processes or tissues
a) More likely to act on a specific receptor - Specificity (chemical) - relationship between chemical structure of drug and pharmacological effects
4
Q
What are some characteristics to consider when administering drugs?
A
- Is it easy to administer?
- Is it well absorbed?
- Is it potent?
- Is it highly selective?
- Is it highly specific?
- Does it interact with other drugs?
- Is it cost effective for the patient?
5
Q
What are sources of drugs?
A
- Micro-organisms (e.g. fungi as a source of antibiotics)
- Humans and other animals (e.g. adrenaline)
- Minerals or mineral products (e.g. iron)
- Substances synthesised in laboratories (e.g. anti-depressants)
- Plants (e.g. caffeine, cocaine, morphine)
6
Q
How do drugs get their names?
A
- Chemical name
a) Precise chemical structure (molecular composition) - Approved name aka non-proprietary or generic name
a) Active ingredient of the drug often derived from chemical name
b) Distinct in sound and spelling but has some relation to similar drugs (e.g. diazepam) - Trade name
a) Proprietary or brand name that individual drug companies use (e.g. Valium) - Trade name
7
Q
What is generic prescribing?
A
- An additional brand of an existing medicine
- Contains same active ingredient
- Can be manufactured and sold by other pharmaceutical companies once the patent for existing brand has expired
- Generic medicines for 40% of prescriptions filled by the Pharmaceutical Benefits Scheme
- Therapeutic Goods Administration (TGA) requires that generic medicine meet the same quality criteria and manufacturing standards as the original brands
a) e.g. Bioequivalence - refers to whether the generic medicine releases the active ingredient into the bloodstream at the same rate and to the same extent as the original medicine
8
Q
What are main routes of drug administration and formulation?
A
- Oral - tablets, capsules, syrups
- Dermal - creams, ointments, lotions, transdermal patches
- Sublingual - tablets, sprays
- Intranasal - Sprays,
9
Q
What are the advantages and disadvantages of oral drug administration?
A
- Advantages:
a) Natural, uncomplicated, convenient
b) Safe - if someone has taken too much, you can induce vomiting (within 30 minutes) - Disadvantages:
a) Slow onset of action - it has to be absorbed after swallowing so won’t be immediate
b) Absorption erratic
c) Inactivation by liver - some drugs may be inactivated by liver before it has a chance to act on body
d) Compliance varies - difficult to keep track of patients
e) Can only be given to conscious patients
f) May cause irritation of the GI
10
Q
What are forms of oral drug formulation?
A
- Tablets:
a) Made of compressed granulated powder
b) Excipient (inert binding material) - allows for small doses to be held together
i) Excipients also help drug to be absorbed and may contain lubricating agent or be sugars to help taste better
ii) Excipients are any material that is not the actual drug to assist in the administration of the drug
iii) All medicines must have the same bioequivalence but not the same excipients (i.e. panadol has better tasting excipients than the coles brand) - Sustained-release preparations:
a) Drug slowly released into GI tract
b) Usually formed by a layer of drug followed by a layer of inert binding material followed by another layer of drug followed by another layer of inert binding material and so on…
i) Cannot control rate of release in individuals - Controlled-release preparations:
a) Semi-permeable membrane - allows drug to release slowly
b) Release constant between individuals - Enteric coated preparations:
a) Tablets coated with material that does not disintegrate in stomach - dissolves in small intestine
b) Useful because it prevents dilation of drug before reaching small intestine, prevents nausea and irritation of stomach, provides delayed drug reaction
c) They cannot be crushed - Capsules:
a) Hard gelatin
b) Soft gelatin - Oral liquid preparations:
a) Syrups - easy to swallow
11
Q
What are the advantages and disadvantages of sublingual and buccal drug administration?
A
- Advantages:
a) Avoids GI tract
b) Avoids activation by liver - hepatic first-pass effect
c) Onset of action may be faster - Disadvantages:
a) Not many drugs can be given via this route
b) Compliance issues
12
Q
What are forms of sublingual and buccal drug formulations?
A
- Tablets
- Sublingual spray
- Lozenges
13
Q
What are forms of rectal drug formulations?
A
- Suppositories
2. Enemas
14
Q
What are advantages and disadvantages of rectal drug (suppository) administration?
A
- Advantages:
a) Can be given to an unconscious person
b) Can be given when there is difficulty swallowing
c) Does not induce nausea or vomiting - Disadvantages:
a) Difficulties with administration
b) Can cause anal and rectal irritation
15
Q
What are the advantages and disadvantages of topical drug administration?
A
- Advantages:
a) Local action - Disadvantages:
a) Some may be uncomfortable to administer
