General principles 2 Flashcards
Formula to calculate the half-life of a drug
t 1/2 = (0.7 x Vd) / CL
What kind of side effects can be seen in a px that is taking first generation antihistamines?
Anticholinergic and antiadrenergic effects, due they’re not receptor specific
This drug is a sulfhydryl compound that binds and inactivates the toxic metabolites of chemotherapeutic agents in urine, such as acrolein.
Mesna
Formula to calculate the drug plasma concentration
Cp = Drug dose / Vd
Intrinsic ability of a drug to elicit an effect. Measure of the maximum ceiling of activity [Emax].
Efficacy
Define potency of a drug
Drug dose that is required to produce a given effect. Affected by the affinity of the drug for its receptor and the amount of drug available
Most common and persistent side effect of opioid use
Constipation
Acetaminophen intoxication pathophysiology
Depletion of glutathione ➡️ overaccumulation of NAPQI ➡️ mitochondrial dysfunction ➡️ oxidative hepatocellular injury
Mechanism of action of N-acetylcysteine in Acetaminophen overdose
Repletes intrahepatic glutathione stores
Most common Cyt P450 inhibitors
MAGIC RACKS Macrolydes Amiodarone Grapefruit juice INH Cimetidine Ritonavir Acute alcohol Cipro Ketoconazole Sulfonamides
Syndrome caused by combination of MAOi antidepressants or non-antidepressant with MAOi activity with serotoninergic medication
Serotoninergic syndrome
- Autonomic instability
- Altered mental status
- Neuromuscular irritability
How many half-lives are needed to reach the steady state?
4-5 t1/2
