Different drugs often compete for the same receptor sites. The drug with the ________ affinity for the receptor will bind to more receptors than the drug with the ________ affinity.

The physicochemical properties of drugs that influence the passage of drugs across biologic membranes are:

Lipid-soluble substances move across the lipoprotein membrane by a passive transfer process called __________.

It utilizes concentration gradient.

__________ is a process by which a substance is transported against a concentration gradient. It is facilitated by carrier cells.

_______________ does not move against the concentration gradient.

It utilizes pinocytosis where there is an invagination in cell wall, and extracellular material is absorbed.

Drugs are present in a solution as either ionized or non-ionized forms.

1. The ionized form has a charge and has low lipid solubility

2. Non-Ionized form has no charge and has high lipid solubility

Which form crosses the cell membrane more easily?

1. Weak acids are better absorbed when the pH is ______ than the pKa.

2. Weak bases are better absorbed when the pH is ______ than the pKa.

In the presence of an infection, the acidity of the tissue _______ (and the pH decreases) and the effect of local anesthetics _________.

The closer the pKa of the drug is to the pH of the environment, the more non-ionized the drug is and the faster it is absorbed.

Drugs that are _____ acids (ex: pKa 3.8) will be mostly non-ionized in the acidic pH of the stomach (pH 2), allowing it to be readily absorbed.

Local anesthetics are weak bases. The closer the pKa of local anesthetics is to the local tissue pH (pH 7.4), the more non-ionized the drug is and the faster it will be absorbed with a quicker onset of action

Lidocaine has a pKa 7.9, and Bupivicaine with a pKa 8.1. Which has a faster onset?

1. If the tissue pH is more alkaline and closer to the pKa values of the drugs, onset of action is slower.

2. Inflamed tissue becomes acidic resulting in less local anesthetic in the non-ionized form.

Absorption of the drug begins in the 1. ___________ to the 2. ________, then to the 3. ___________.

Select the factors that affect distribution of a drug.

In regards to metabolism, also known as biotransformation, before elimination the drug must be biotransformed in a __________ form

Only drugs in their free form are available to exert its pharmacologic effects.

1. Metabolism (biotransformation) occurs in the __________.

2. After it is biotransformed, it is called a ____________.

Drug metabolism produces compounds that are more polar (ionized) and more easily excreted.

Select other ways drugs can be excreted.

Changes non-ionic, lipophilic drug to a more ionic, hydrophilic metabolite to ease excretion

If the product of this phase is hydrophilic enough, it is excreted by kidneys.

The metabolite from a phase isn’t hydrophilic enough to pass through kidneys.

The drug goes back to the liver to be combined with a highly water soluble compound.

It takes about ______ half-lives for a drug to be “considered” eliminated from the body

The larger the half-life ( t½) value, the longer it takes for a drug to be eliminated from the body for a patient considered healthy.

The route of drug administration (ROA) for a drug that goes through the GI tract is considered:

The route of drug administration (ROA) for a drug that bypass the GI tract is considered:

The route of drug administration (ROA) for a drug that is administered directly on tissue is considered:

Emergency drugs ROA would be considered:

Smoking cessation patches ROA would be considered:

Local anesthetic ROA would be considered:

Nitroglycerin spray ROA would be considered:

Amoxicillin ROA would be considered:

An EpiPen ROA would be considered:

An Albuterol inhaler ROA would be considered:

1. Oral administration produces a slower onset of action than parenterally administered agents.

2. An advantage of this route is the large absorbing area present in the large intestine.

The dose required to produce desired effect in 50% of experimental beings

The closer the median effect dose (ED50) is to the lethal dose (LD50), the more dangerous the drug is because the chance of taking an overdose is greater.

An agonist is a drug that:

1. Has affinity for a receptor

2. Combines with the receptor

3. Produces an effect.

Ex: Naturally occurring neurotransmitters are agonists.

Which is not a type of antagonist drug?

1. A competitive antagonist is a drug that, (1) has affinity for a receptor, (2) combines with the receptor, (3) produces no effect by blocking agonist.

2. The antagonist competes with the agonist for the receptor, and the outcome depends on the relative affinities and concentrations of each agent.

1. Non-competitive antagonists bind to a receptor site that is different from the binding site for the agonist.

2. Its presence increases the maximal response of the agonist

1. A physiologic antagonist has affinity for a different receptor site than the agonist.

2. Its presence increases the maximal response of the agonist by producing an opposite effect via different receptors.

This type of antagonist blocks agonists.

This type of antagonist binds at a different receptor site, and its presence reduces the maximal response of the agonist.

This type of antagonist has affinity for a different receptor site causing an opposite affect than agonists.