Untitled Quiz

Drug Administration Routes

• Intravenous administration is the most desirable route for administering an antidote in a drug overdose as it results in the fastest onset of action.
• Intramuscular, subcutaneous, and transdermal routes are less desirable because of slower absorption rates.
• Oral administration is typically the slowest method.

Drug Absorption

• Drug A, a weakly basic drug with a pKa of 7.8, will readily absorb in the duodenum (pH approximately 6.1) when given orally.
• The stomach (pH of 2.5) presents a less favorable environment for absorption of weakly basic drugs like Drug A due to the low pH.
• Drug A won't readily absorb in the mouth (pH approximately 7.0) or the jejunum (pH approximately 8.0) or the ileum (pH approximately 7.0)
• The absorption rate is dependent on the pH of the surrounding environment and the pKa of the drug.

KR2250

• KR2250, an investigational cholesterol-lowering agent, has a high molecular weight, and is extensively bound to albumin.
• This agent will have a high apparent volume of distribution (Vd).

Vancomycin Loading Dose

• A 40-year-old male patient (70 kg) received a 2000 mg intravenous loading dose of vancomycin.
• The peak plasma concentration of vancomycin was 2 mg/L.

Volume of Distribution

• The apparent volume of distribution for a particular drug is a measure of the apparent distribution of a drug throughout the body fluids in relation to the dose administered.
• It's calculated as the total dose divided by the plasma concentration.
• In this specific case, it has been given as 8.5 mg/L, and the apparent volume of distribution is 70 L/kg.

Antiseizure Drug and Dialysis

• In a patient with renal disease undergoing dialysis, the use of an antiseizure drug X will likely require adjustments in dosage or a different route to account for how the drug is processed differently as compared to a normal kidney function.
• A change in half-life or dosage may be observed.

Clopidogrel and Omeprazole

• Patients taking clopidogrel (an antiplatelet agent) and aspirin daily, along with a potent CYP inhibitor (omeprazole), for heartburn may have reduced antiplatelet activity of clopidogrel. This is due to the inhibitory effect of omeprazole on the metabolism of clopidogrel, resulting in reduced efficacy of the drug.

Phase II Drug Metabolism

• Phase II of drug metabolism involves reactions that add a larger, more polar chemical group to the original drug molecule to increase its water solubility.
• This type of metabolism often leads to the inactivation of the drug, but in some cases can make it more readily excreted from the body.
• One example of a Phase II reaction is sulfation.

Anti-hypertensive Drug Half-life

• A new antihypertensive drug has a 12-hour half-life after a continuous intravenous infusion.
• This means that approximately 72 hours would be required to ensure a steady state.
• This would be estimated to require at least 48 hours.

Oral Loading Dose for Diabetes

• A 64-year-old female (60 kg) patient with type 2 diabetes, receiving experimental Drug A, requires a dosage of 360 mg to achieve the desired steady-state plasma concentrations of 3 mg/L considering an oral bioavailability of 90% and Vd of 2 L/kg.

Digoxin Dosage

• A patient receiving 160 mcg of digoxin intravenously has a plasma digoxin level of 0.4 ng/mL; the target plasma concentration is 1.2 ng/mL. The required additional digoxin dose for this patient is 320mcg. The volume of distribution is 400L.

GABA Receptor Agonist

• Activation of the GABA receptor subtype A opens chloride channels that decrease the chance of generating an action potential.

Lorazepam and Diazepam Anxiolytic Response

• If 1 mg of lorazepam produces the same anxiolytic response as 10 mg of diazepam, lorazepam is more potent than diazepam.

Oxycodone and Aspirin Analgesic Response

• If 10 mg of oxycodone produces a greater analgesic response than does aspirin at any dose, oxycodone is more efficacious than aspirin.

Propranolol and Epinephrine

• Epinephrine is an agonist and propranolol is a competitive antagonist. Epinephrine activity is lessened by propranolol's competitive blockade.

Picrotoxin and Diazepam

• In the presence of picrotoxin, diazepam is less efficacious. Picrotoxin is a noncompetitive antagonist.

Antipsychotic Medications and D2 Receptors

• The mechanism of antipsychotic effects for haloperidol, chlorpromazine, and clozapine is via binding to D2 receptors.

Spare ß1-Adrenergic Receptors

• The number of spare ẞ1-adrenergic receptors influences the maximum effect (response) of the agonist, epinephrine.
• Spare receptors are not necessarily active in the absence of epinephrine but they are still contributing to the total response.

Up-Regulating a1-Adrenergic Receptors

• Daily use of amphetamine, or other compounds, that cause release of norepinephrine, can up-regulate postsynaptic a1-adrenergic receptors.
• Daily use of an α1 receptor agonist (such as phenylephrine) can also up-regulate postsynaptic alpha-1 adrenergic receptors.

Methylphenidate

• The therapeutic index of methylphenidate is 0.3.
• Methylphenidate has a higher potency for producing nausea than for the therapeutic effect it has on ADHD.

Chlorpropamide Overdose

• In the case of a chlorpropamide overdose in a 3-year-old, urinary excretion would primarily be accelerated by giving NaHCO3, an alkalinizing agent.
• At a lower pH, the degree of ionization is reduced, and absorption of the drug would be slower from the stomach and higher in the small intestine.

Botulinum Toxin

• Botulinum toxin is a large protein molecule that permeates cells through endocytosis.

Ampicillin Elimination

• Ampicillin is eliminated by first-order kinetics. This means that the rate of elimination is proportional to the amount of drug in the body at any given time (plasma concentration).

Drug Distribution

• Drug distribution depends on several factors, including blood flow to the tissue, the concentration gradient of the drug between the blood and the tissue, and the ability of the drug to bind to plasma proteins.
• Lipid soluble drugs have a higher distribution in fat tissues.

Pharmacokinetics

• The distribution of a drug to a given tissue is dependent on blood flow to that tissue and not independent of blood flow.
• Drugs that are highly bound to plasma proteins have slower distribution into tissues, as protein-bound drugs cannot cross membranes.

Animal Testing

• Animal testing is necessary to evaluate the safety and efficacy of new drugs before human clinical trials can commence.
• Results from animal testing may be relevant to human drug responses and use.

Dominant Lethal Test

• The dominant lethal test assesses a chemical's mutagenicity by exposing male animals to the compound before breeding. Pregnancy and fetal outcomes are then examined.

Clinical Trials

• Phase 1 clinical trials involve a small number of healthy volunteers, evaluating safety and pharmacokinetic profiles of a new drug
• Phase 2 clinical trials involve a larger group of patients with the disease, assessing efficacy and dosage in the context of the proposed use.
• In Phase 3 clinical trials, a larger group is tested for safety and efficacy, and the results are used to support regulatory approvals for marketing or use of the drug.
• Phase 4 involves post-marketing surveillance to monitor, gather additional data, identify new uses/indications, and further explore the long-term safety profile of a new therapy.

Clinical Trial-Anti-inflammatory Drug

• A phase 3 clinical trial of a new analgesic drug for mild pain would likely include a placebo (negative control), the current standard, (positive control) therapy known to help with pain, and a group of patients (1000-5000) requiring pain management.
• The clinical trial also needs to include a double blind study (where patients and those administering the drug are kept unaware of which intervention is being administered).

Ames Test

• The Ames test is a rapid and inexpensive method to assess whether a compound may be a potential carcinogen by inducing mutations in certain bacteria.

New Drug Development

• Safety concerns, such as teratogenicity, mutagenicity, and carcinogenicity must be addressed before humans use a new drug.
• Food supplements and herbal remedies must be shown to be effective, before they can be sold as a product.

Digoxin Blood Level

• The required additional dose needed to achieve the desired plasma concentration is 128 mcg. given that there's a 100% bioavailability. The blood to volume of distribution should be found from the equation.

Lorazepam and Diazepam

• 1 mg of Lorazepam and 10 mg of Diazepam have the same anxiolytic response.
• Lorazepam is more potent. Potency describes the relative amount of a drug that is required to have a quantifiable effect and can be compared to other drugs which are more effective or less effective.