VTHT 1349 Practice Problems 1. Practice: Tell whether the following drugs would be more in the ionized form or more in the neutral/un-ionized form: a. Acidic drug with pk=3 in solution pH 5 b. Basic drug with pk6 in solution pH-5 c. Basic drug with pk-6 in solution pH-7 d. Acidic drug with pk-6 in solution pH=5 e. Acidic drug with pk=4 in solution pH-2 f. Basic drug with pk-7 in solution pH=2 8. Acidic drug with pk-5 in solution pH=5 h. Basic drug with pk=9 in solution pH=8 2. With a belch and a martini-induced hiccup, Harvey Wallbanger of the XCX Drug Company wanders into your exam room. Today Harvey is selling two weak acidic antibiotics of the same type. Both are given parenterally. The only difference between the two antibiotics is that one of the acidic drugs has a pk-6 and the other has a pk=8. Basd on the route of administration of the drug, which drug would you buy? Why? 3. Harvey also has an injectable basic local anesthetic that comes in two forms, pk=5 and pk=9. Remembering that we want the injected local anesthetic to remain in the tissues where it can keep working to numb the tissues, which drug form would you buy and why? 4. Doc wants to use an antibiotic for a dog's bladder infection. Consequently he wants a drug that is renally excreted and that once it gets into the kidney filtrate it stays there instead of being reabsorbed back into the body. The basic drug he has chosen has a pk=7. Doc wants you to change the pH of the urine with orally administered medication so the drug gets trapped in the urine. Do you administer compounds that will alkalinize the urine or acidify the urine to trap the drug? (assume the urine pH=7 before you begin treatment)