Pharmacology Lecture One - Pharmacokinetics/dynamics and Drugs for pain

Antidotes and Reversal Agents

Antidotes and Reversal Agents

Acetaminophen

Acetylcysteine

Benzos

Flumanzenil

Cyanide poisoning

Methylene blue

Digitalis

Digoxin immune FAB

Ethylene poisoning

Fomepizole

Heparin and enoxaparin

Protamine sulfate

Iron

Deferoxamine

Lead

Succimer

Mag suflate

Calcium gluconate

Naroctics

Naloxone

Wafarin

Vitamin K (Phytodadione)

What are the four processes of pharmacokinetic

Absorption, distribution, metabolism, and excretion

How many half lives does it take to plateu or for the drug to reach an insignificant amount

4-5 half lives

How do we determine the therapeutic index

LD50/ED50

What are three drugs with a narrow TI

Digoxin, lithium, warfarin

Why should grapefruit juice be avoided with certain drugs

Because it inhibits an enzyme in the liver called P-450, thus it increases the level of the drug in the blood

Which five drugs should be avoided with grapefruit (NVMSS)

Nifedipine

Midalozam

Verapamil

SSRIs

Stains

What are two drugs that are known to cause a prolonged QT interval

Haloperidol and Ondasetron

Drug-Drug interactions

Drug-Drug interactions

Which drugs should be avoided for ACE Is and why?

K+ sparing meds should be avoided because it can lead to hyperkalemia

Which drugs should be avoided for Metformin and why?

Contrast dye should be aoided because it can cause nephrotoxicity; hold metformin 24 hours before and 48 hours after receiving contrast dye!!

Which drugs should be avoided for Nitro and why?

Erectile dysfunction meds (phosphodiesterase inhibtors) because this will cause hypotension

Which drugs should be avoided for MAOIs and St Johns Wort and why?

Other antidepressants bc it can lead to serotonin syndrome

Drug-Food interactions

Drug-Food interactions

Which foods should be avoided for CCBs, statins, and anticoagulants and why?

Grapefruit juice should be avoided because it blocks the enzyme (P-450) which metabolizes these drugs, thus increasing the levels in the body

Which foods should be avoided for MAOIs and why?

Tyramine-rich foods such as wines, aged cheeses, salami, and chocolate due to risk for hypertensive crisis

Which foods should be avoided for Warfarin and why?

foods high in vitamin K such as dark, leafy greens bc these counteract the actions of warfarin and can increase risk for clotting

Drug-disease interactions

Drug-disease interactions

Which drugs should be avoided for Asthma and why?

BBs because they can cause bronchospasm due to location of beta 2 receptors on the lungs

Which drugs should be avoided for Chronic liver diseaseand why?

Warfarin because CLD leads to increased sensitivity to this drug and ultimately increased bleeding

Which drugs should be avoided for CHF and why?

CCBS and NSAIDs should be avoided because they cause sodium retention and also increase risk of cardiac events.

Steroids should also be avoided because they lead to sodium and water retention

Which drugs should be avoided for Epilepsy and why?

TCAs, antimalarials, and antipyschotics should be avoided because they reduce the seizure threshold

Which drugs should be avoided for Parkinson’s and why?

COX-2 inhibitors (ASA, naproxen, ibuprofen) because they cause worsening of Parkinson’s symptoms

Which drugs should be avoided for Renal failure and why?

NSAIDs because they cause nephrotoxicity

Which drugs should be avoided for respiratory failure and why?

Neuroleptics; opioids bc they cause respiratory depression

Drugs for pain

Drugs for pain

What do most local anesthetics end in

caine

Why is system absorption of lidocaine bad

because this drug is only meant to be abosrbed locally, so systemic absorption can result in palpiations, tachycardia, and hypotension

What’s used alongside lidocaine to prevent systemic absorption

A vasoconstrictor like epinephrine

What do opioids typically end in

ine

What does morphine/opioids suppress

CNS!! Leading to general depression

Opioid side effects: MORPHINE

Miosis

Out of it

Respiratory depression, reduced salivation

Hypotension, H/A

Infrequent elimination (constipation, urinary retention)

Nausea/ nervousness

Emesis (**warn pts that GI side effects are common)

What’s the difference between morphine and methadone

Methadone has a long half life and thus no euphoric effects because there’s no peak like there is with morphine. This means it can be used for opioid withdrawal

Should we quickly titrate methadone?

NO

What’s buprenoprhine

This is an opioid agonist-antagonist that has a lower potential for abuse because there’s no euphoric high.

What should the nurse be aware of after giving a pt nalaxone

Be aware that the pt will experience immediate withdrawal and is going to be PISSED bc now you jsut took awy their high and they’ll be in a lot of pain

What’s a common ending for Cox inhibitors

Fen

What is the COX enzymes 1 and 2 responsible for? (6 functions)

Stomach → gastric protection

Kidneys → increases renal function by sending more blood to kidneys

Coagulation → causes platelet aggregation

Blood vessles → causes vasodilation

Causes inflammation at injured tissue site

Causes fever and pain r/t injured tissue site

How do COX inhibitros effect the body

Stomach → gastric ulceration

Kidneys → renal impairment

Coagulation → decreases platelet aggregation leading to increased bleeding

Blood vessels → vasoconstriction

Decreases inflammation at tissue site

Decreases fever and pain

How long should ASAs be held before surgery

5- 7 days!!!

Why are ASAs/aspirin common for pts at risk for ischemic disease

Because they decrease platelet aggregation

Why is aspirin avoided for peds pts? whats the exception?

Avoided d/t risk for Reye’s syndrome and the only time it’s used is for Kawasaki’s disease

What’s the main sign of Aspirin toxicity

TINNITUS!!!!

whats the max dose of acetaminphen? What about for pts with long term use

Max dose= 4g; long term use max dose = 3 g