Pharm principles Flashcards
Pharmacokinetics includes
How the body absorbs, distributes, metabolizes, and excretes the drug
PharmacoDynamics is what the Drug does to the body, such as
which receptors it binds to
Where are most oral meds absorbed
small intestine or liver
Distribution
When the drug leaves systemic circulation and enters the interstitium and cells
The drugs are re-distributed according to their protein and fat content
Most meds are lipophilic and highly protein bound. Only the unbound (free) portion is active. Therefore, if you have low protein (for example from malnutrition or aging) you will experience stronger med reaction or even toxicity.
Also, if you have high fat mass compared to lean body mass (such as older people), you will have erratic reactions to meds.
First pass metabolism
Process by which the med is changed by the P450 enzymes in the intestine/liver
Half life
This determines the dosing schedule and the time needed to reach steady state.
It takes about 5 half-lives to reach steady state, and 5 half lives to eliminate the drug
Metabolizing in special populations
10% of whites are poor metabolizers of P450 2D6
20% of asians are poor metabolizers of P450 2C19
Children may be faster metabolizers of several P450 enzymes compared to adolescents
Meds that inhibit P450 (which raises other med levels)
Bupropion SSRIs Clomipramine (TCA) Cimetidine Clarithromycin Fluoroquinolones Ketoconazole Nefazodone
Meds that induce P450 (which lowers other med levels)
Carbamazepine Hypericum (St John's Wort) Phenytoin Phenobarbital Tobacco
Disease of which organs causes high or even toxic med levels
Liver and kidney
Renal Clearance
Meds that reduce renal clearance, like NSAIDs (Ibuprofen) can increase levels of meds that are renally excreted. That is why you can’t give ibuprofen with Lithium, it will raise the Li level.
Metabolism in older adults
Older people are more sensitive to meds because they have less intracellular water, protein binding, low muscle mass, decreased metabolism, and increased body fat concentration
Most meds are lipophilic and highly protein bound. This means that older adults (who have more fat to store meds and less protein for meds to bind to) have more meds active in their system. They can develop toxic levels.
Agonist vs inverse agonist
Agonist causes no effect, inverse agonist causes the opposite effect
Excitatory response
Depolarization, involve opening all of the sodium and calcium channels so these ions go into the cell
Inhibitory response
Repolarization, involves opening chloride channels so that chloride goes into the cell, potassium leaves the cell, or both
tachyphylaxis
The med suddenly becomes less effective
a DEA number is required for
prescribing controlled substances
Which class: Loxapine
1st gen
Which class: Thiorridazine
1st gen
Which class: Thiothixene
1st gen
Which class: Mesoridazine
1st gen
Which class: Perphenazine
1st gen
Which class: Trifluoperazine
1st gen
Which class: Iloperidone
2nd
Which class: Asenapine
2nd
Which class: Clomipramine
TCA
Which class: Amoxapine
TCAs
Which class: Amitriptyline
TCA
Which class: Desipramine
TCA
Which class: Nortriptyline
TCA
Which class: Doxepin
TCA
Which class: Trrimipramine
TCA
Which class: Imipramine
TCA
Which class: Protriptyline
TCA
Which class: Citalopram
SSRI
Which class: Fluvoxamine
SSRI
Which class: Paroxetine
SSRI
Which class: Phenelzine
MAOI
Which class: Tranylcypromine
MAOI
Which class: Selegeline
MAOI
Schedule 1 meds
Non medicinal High abuse potential Used for research only Not legally available by prescription Examples are heroin and marijuana
Schedule 2 meds
Medicinal drugs in current use
No telephone orders allowed
No refills allowed on a prescription
Morphine, fentanyl, oxycodone, other pain meds, amphetamines, methylphenidate
Schedule 3 meds
Telephone order is allowed if followed by a written prescription
Prescription must be renewed every 6 months
Refills limited to 5
Appetite suppressants, butalbital, testosterone, buprenorphine/naloxone
Schedule 4
Less abuse potential
Xanax and the other benzos, modafinil, armodafinil, phenobarbital, zolpidem (ambien), eszopiclone (Lunesta)
Schedule 5 meds
Medicinal drugs with the lowest abuse potential
Handled in a way similar to non-controlled meds
Buprenorphine, cheratussin (robitussin) with codeine
Possible risks of meds during pregnancy
Problems with appetite Transient agitation or sedation Premature labor Drug discontinuation symptoms Teratogenic effects
Pregnancy ratings for meds
A - Studies show no risk B - No evidence of risk in humans C- Risk cannot be ruled out D- Positive evidence of risk X- Absolutely no
Teratogenic effects of benzos
Floppy baby syndrome, cleft palate
Teratogenic effects of carbamazepine
Neural tube defects
Teratogenic effects of Lithium
Epstein anamoly
Teratogenic effects of divalproex sodium (depakote)
Neural tube defects (specifically spina bifida), atrial septal defect, cleft palate, long term developmental deficits.
Meds that can induce depression
Beta blockers benzos Steroids Interferon Isotretinoin Some retroviral drugs Antineoplastic drugs Progesterone
Medications that can induce mania
Steroids
Disulfiram
Isoniazid
Antidepressants in persons with bipolar
Meds that can cause a false positive Amphetamine screen
Stimulants Bupropion Fluoxetine Pseudoephedrine Trazadone/Nefazodone Ranitidine
Meds that can cause a false positive Alcohol screen
Valium
Meds that can cause a false positive Benzos screen
Sertraline
Meds that can cause a false positive Cocaine screen
Amoxicillin
Antibiotics
NSAIDs
Meds that can cause a false positive Heroin/morphine screen
Quinolones
Rifampin
Codeine
Poppy seeds
Meds that can cause a false positive Methadone/PCP screen
Dextromethorphan, nyquil
