Pharmacokinetics

Question 1

What charge of a drug is better for cross membranes and to be excreted renally?

Answer 1

Nonionized (uncharged, lipid soluble) ▶️ only this form can crosse membrane
Ionized (water soluble) ▶️ better excreted by kidney

Question 2

Why do you use lactulose in hepatic encephalopathy? How does it work?

Answer 2

Gut bacteria
Lactulose ▶️ lactic acid ⏩ acidifies fecal masses
Acid
Ammonia (NH3; toxic ⬆️ in hepatic encephalopathy) ▶️ ammonium (NH4+; better cleared)

Question 3

Most rapid rout of absorption.

Answer 3

1. Intravenous (really don’t need absorption - 100% bioavailability)
2. Inhalation
3. Sublingual

Question 4

Safer drug profile during pregnancy.

Answer 4

Water soluble
Large molecular weight
Protein binding

*one drug with all features is ver unlikely, at least 2.

Question 5

What could occur if give together macrolide and theophylline?

Answer 5

Macrolide (inhibitor) ▶️ (-) cytochrome P450 ▶️ ⬆️ theophylline (substrate) ⏩ ⬆️ risk of arrhythmia

Question 6

What drugs can cause drug-induced SLE? Which is the mechanism? Which antibodies are associated?

Answer 6

Hydralazine, procainamide, isoniazid (HIP)
Slow acetylation
Antihistone antibodies

Question 7

How do you treat an overdose of weak acid? Examples.

Answer 7

Alkalinized environment ▶️ bicarbonate

ASA, methotrexate, phenobarbital

Question 8

How do you treat a weak base overdose? Examples.

Answer 8

Acidify environment ▶️ ammonium chloride

Amphetamines, PCP, TCAs