They eye: closed angle glaucoma

I am sorry we did not have time to cover that. But you should be aware of the various drugs useful in treating, symtomatically by reducing intraocular pressure, close angle glaucoma. In the end it is quite easy, though initially looking complex: You have to just remember the anatomy of the anterior eye structures and where the receptors are located.

• Circular muscle has M receptors.  
• Radial muscle has alpha1 receptors. 
• Cilial muscle has M-receptors. 
• Cilial epithelium has beta-2 receptors (and these control aqueous humor production). 
• Alpha-2 receptors are located - where? No idea. but stimulating them with agonist opens alternative uveoscleral fluid outflow. 

Contracting the iris re-establishes some Canal of Schlemm outflow. All of this ism like an autonomic clearing house!
Additionally to using ANS drugs, one can reduce aqueous humor outflow by using (a) a carbonic anhydrase inhibitor, like  aceazolamide, or (b) one can draw fluid from the eye osmotically by increasing plasma osmolality with glycerol  (just by drinking a cup of it) or injected mannitol.

In reality, 2-3 of these approaches are employed!

New pharm learning site??

I love this title I just found on the Internet (although maybe it should be re-titles as "...by Dummies):

I did some clicking but found, unfortunately, that it is a dental pharm course....

Autonomic drug puzzle

We normally conclude the discusssion of ANS drugs with a "puzzle". I have no idea where this came from, and certainly it is not a fully realistic scenario that would be observed exactly like this in a real animal experiment. But the puzzle serves to review and thus gain additional understanding about tyhe functionalities of the ANS and ANS drugs. The recorded file now has been forwarded to your class rep. It is 20 MB and some emails cannot handle this - I am sure you will be colleagually (a new word?) interactive within your class and each student will be able to get it and listen to it.

Wine & Cheese parties

These are a no-no for persons who take MAO inhibitors like selegeline against depression. Reason: Tyramine can be taken up into adrenergic nerve terminals or varicosities and then replace norepinephrine. The outpour of norepinephrine then precipitates a hypertensive crisis and accelerates the heart beat. The outcome can be death from stroke or maybe arrhythmia and cardiac arrest. Wine and cheese are foods that contain significant amounts of tyramine - this normally is rapidly metaboized by MAOs and remains inconsquential, except when the enzymes are inhibited.

Preceding dosing problem - no response

A small reminder: Nobody seems to have bothered trying out the preceding dosing problem. You better reconsider!

A dosing problem for your entertainment

A  patient is maintained on  an oral drug, given 4-hourly, but develops some adverse effects too frequently during periods of peak plasma concentrations.  Measurements show that his plasma concentration fluctuates between 120 and 60 microgram/L.

The physician decides he would rather place him on a continuous infusion.

What maintenance dose rate would you suggest then?

Parameters for the drug are:

Bioavailability 25%

Volume of distribution:  2.4 L/kg

Pt. Weight: 80 Kg

Plasma Half-life: 4 hours

Look for previous entries re. pharmacokinetics

Make sure you scan through ALL entries in this blog - you will find some that are relevant to what we have covered or will cover in this course. For example, there is a useful module telling you how to deal with the determination of AUC....search for "AUC" or scan through all previous entries...

Pharmakokinetics course online

I mentioned to you the boomer.org website by David Bourne.

For those who like to play games on their computers, here, for once, is a useful "game": Display time curves using a Java module provided by Bourne:

The link  to the course contents page is this:    http://www.boomer.org/c/p1       Here is the example where you to vary inputs and show resulting PC-versus-Time curves for oral drug administration, as follows: http://www.boomer.org/c/p1/Ch15/Fig57/Fig57.html

In some cases the formula section is f ollowed by links to Java graphics modules where you can play around by changing parameters! 

Have fun!

Welcome to Spring 2012 Class

So, here we go:

• Sign up for email notifications and/or as a member.
• Participate in this blog by commenting (always indicate whether you find an entry informative, interesting, useful or boring) and
• Consider sometimes to provide an entry - referring to something you read, saw or wonder about (you would send your entry to me, and I will enter it).
• Ask for content: more questions or more of what?
• When asked a question, always try for an answer.
• Had an experience with a drug reaction or issue you wish to share?

There are plenty of ways to make this interesting for us all....