Basics of Pharmacology Part II

Summary

This lecture covers key aspects of pharmacology, focusing on drug actions, effects, and side effects. It explains the concepts of drug half-life, therapeutic levels, and the importance of monitoring drug levels to avoid toxicity. The lecture also highlights potential adverse effects on various body systems, including the nervous, liver, gastrointestinal, urinary, and hematology systems. Emphasis is placed on the role of healthcare professionals in understanding medication administration, monitoring patient responses, and ensuring effective treatment with minimal side effects.

Takeaways

• 💊 Drugs are eliminated from the body through metabolism and excretion, with half-life being the time required to eliminate 50% of the drug.
• ⏳ Half-life impacts dosing frequency; longer half-lives mean less frequent dosing, which is important for geriatric patients.
• 📈 Drugs have an onset, peak, and duration; understanding these helps manage therapeutic levels and side effects.
• 🩺 Therapeutic levels are essential for drug effectiveness; levels too low render the drug ineffective, while too high can cause toxicity.
• 👂 Certain drugs can cause ototoxicity (ear damage) and nephrotoxicity (kidney damage), highlighting the importance of monitoring.
• 📉 Side effects of medications can range from mild (nausea) to severe (adverse reactions like anaphylaxis), with some side effects being system-specific.
• ⚠️ Allergic reactions, including anaphylaxis, are medical emergencies; patients should wear medical alert bracelets.
• 🧠 Nervous system side effects include confusion, depression, and delirium, while the liver and GI system are also susceptible to drug damage.
• 🔬 Monitoring blood levels and patient symptoms is crucial for safe and effective medication administration.
• 👩‍⚕️ Healthcare professionals must understand drug actions, side effects, and proper administration to advocate effectively for patients.

Q & A

What is the definition of half-life in pharmacology?

Half-life in pharmacology refers to the time required for 50% of a drug to be eliminated from the body.

Why is half-life important when considering medication for geriatric patients?

Half-life is important for geriatric patients because medications with long half-lives need to be taken less frequently, which is crucial to avoid excessive sedation and other side effects.

What are the three key phases of drug action mentioned in the lecture?

The three key phases of drug action are onset (when the drug starts to take effect), peak (when the drug reaches its highest concentration at the target site), and duration (how long the drug has a physiological effect).

What is the difference between a therapeutic effect and a side effect?

A therapeutic effect is the desired effect of a drug for treating a disease or symptom, while a side effect is an undesired effect that may occur in addition to the therapeutic effect.

Why is it important to monitor blood levels of certain medications like antibiotics and anticonvulsants?

Monitoring blood levels is important to ensure the drug concentration remains within the therapeutic range. If the level is too low, the drug may not work effectively; if too high, it can cause toxicity.

What is ototoxicity, and which drug is known to cause it?

Ototoxicity is ear poisoning that can result from exposure to certain drugs, leading to hearing loss or balance issues. Gentamicin, an antibiotic, is known to cause ototoxicity.

How can nephrotoxicity be monitored, and which common drugs may cause it?

Nephrotoxicity, or kidney damage, can be monitored by evaluating blood tests like BUN (blood urea nitrogen). Non-steroidal analgesics like ibuprofen or Motrin are examples of drugs that may cause nephrotoxicity.

What are adverse reactions, and how are they different from side effects?

Adverse reactions are severe side effects such as death or shock, which are much more serious than common side effects like nausea or constipation. Adverse reactions often require a change in medication.

What are the potential side effects of drugs on the nervous system?

Potential side effects of drugs on the nervous system include agitation, confusion, delirium, depression, drowsiness, decreased respiration, and coma.

Why is it important for healthcare professionals to assess patients before administering medications?

It is important to assess patients before administering medications to obtain baseline data, such as blood work and vital signs, to ensure proper absorption and distribution of the drug and to monitor for any potential problems.