Intro to Pharm for PTs Flashcards
Why should PTs study pharmacology?
- Drugs affect PT
- PT affects drugs
- PTs should be able to recognize and respond to ADRs
Chemical Name
Nomenclature
refers to specific compound’s structure, long & cumbersome
Generic Name
Nomenclature
derived from chemical name, somewhat shorter, non-proprietary
Trade Name (Brand name)
Nomenclature
assigned to compound by pharmaceutical company for marketing purposes
Schedule I- Classification of Controlled Substances
Drugs, substances, or chemicals with no currently accepted medical use and a high potential for abuse
(Heroin, LSD, Marijuana, MDMA, etc.)
Schedule II- Classification of Controlled Substances
Drugs, substances, chemicals with a high potential for abuse and use potentially leading to severe psychological or physical dependence. Accepted for medical use
(Methamphetamine, Oxycodone, Morphine, Methadone, Fentanyl, Cocaine, etc.)
Schedule III- Classification of Controlled Substances
Moderate or lower abuse potential compared to II drugs
(Anabolic steroids, testosterone, codeine, ketamine, etc.)
Schedule IV- Classification of Controlled Substances
Lower abuse potential compared to III drugs and lower risk of dependence
(Diazepam, Lorazepam, Phenobarb, Tramadol, etc.)
Schedule V- Classification of Controlled Substances
Lowest abuse potential
(Low dose opioids in cough meds, lamotil, pregabalin, etc.)
What is a drug?
Chemical substance is main ingredient
Bio-equivalence
Generic drug forms as safe and effective as og brand name if:
1. generic drug undergoes testing to establish same active ingredients, pharmokinetic profile, administration route, and therapeutic effects
If criteria not met, can only assume substitution of generic drug for brand name will only produce similar effects
How can drugs affect therapy sessions?
- By hindering therapy (i.e. impairing cognition or motor function)
- By facilitating therapy (i.e. pain management)
- By contributing to pt safety (i.e. respiratory medications)
Pharmacology
Pharmacotherapeutics (Pharmacokinetics and Pharmacodynamics) and Toxicology
Pharmacokinetics (PK)
What the body does to the drug
* A- absorption
* D- distribution
* M- metabolism
* E- excretion
Pharmacodynamics (PD)
What the drug does to the body
* MOA
* Dose response (efficacy, potency, therapeutic index)
* Effectts
* Side effects aka ADR
Bioavailability definition
- amount of drug that can gain access to systemic circulation
- parameter expressed as % of drug adminstered that reaches blood stream
- impacted by absorption (stomach acidity, gastric emptying, surface area, GI enzyms, developmental changes)
Bioavailability depends on
- Route of adminstration
- Drugs ability to cross membrane barriers (active, passive, facilitated, special processes)
Factors affecting drug distribution
- Tissue permeability
- Blood flow
- Plasma proteins binding
- Subcellular components binding
Where are drugs stored when distributed?
Adipose, bone, muscle, organs
What is volume of distribution (Vd)
Ratio expressing amount of drug adminstered/concentration of drug in plasma
Metabolism of drugs
- Metabolite formation
- Biotransformation by liver via Cytochrome P450 (CYP) and others
- Cellular mechanisms
CYP-Induction and CYP-inhibition
CYP induction= increase enzyme levels –> increased metabolism of drugs –> decrease effects of drug
CYP inhibition= decrease enzyme levels –> decrease metabolism of drugs –> increase effects of drug
Drug elimination/excretion rates
Kidneys/nephron is major site of drug elimination
* Clearance- ability of organs/tissues to eliminate drug
* Half life- amount of time required for 50% of drug remaining in body to be eliminated (usually 5-7 half lives for complete eliminate)
Half life example Q
Half life is 4 hours, how much time to remove drug from body? Until how many hours after taking drug is it still effective?
100mg 0hr –> 50mg 4h –> 25mg 8h –> 12.5mg 12h –> 6.25mg 16h –> 3.12mg 20h –> 1.56mg 24h –> 0.78 28h
28h/4= 7 half lives until drug is eliminated. Drug is still detectable and effective at 24 hours.
