First Impressions of the SymlinPen

I saw my endo today and I was given a sample SymlinPen 60. I've blogged previously about my experiences with Symlin. So in this post I'll just talk about the pen itself.

When I got home I snapped some pictures before using it.


As you can see the pen itself is a little longer and thicker than a large ballpoint. It's an awkward fit in my shirt pocket, only about a half-inch of the clip is actually holding it in place. I'll definitely keep it in my diabetes kit.

I had planned to use the pen at lunchtime. When I opened the box and took the cap off I found...no pen needle in place. That's right, the sample cannot be used immediately. It's like a Christmas toy that has no batteries and all the stores are closed.

Luckily I had some 10-year old pen needles left from when I used an insulin pen, and once I got home I grabbed one of these. It fit perfectly.



The pen has a dial at one end that lets you choose to dispense Symlin in doses of 15, 30, 45, or 60 micrograms (mcg). For comparison, 10 units of insulin is equal to 60 mcg of Symlin. Many people with type 1 diabetes will use 45mcg or less per meal. If you have type 2 diabetes and are taking insulin then the Symlin 120 pen is probably more useful, it will deliver either 60 or 120 mcg.

To start with I attached the pen needle, dialed up a 15 mcg dose, pulled back the end to prime the pen and dispensed the dose into the air. This was to fill the needle. I repeated this several times until I saw a stream of Symlin.

Then I dialed up my regular dose of 60 mcg and was able to inject it using the wonderfully small pen needle. If you put the needle cover back on, you can replace the pen cap with the needle still in place.

There's an interesting design feature, where you can stand the pen on end. I'm not sure what the benefit of this is, or whether it's just a side-effect of having a built-in plunger.

There are markings on the barrel of the plunger that help you determine whether it's pulled back far enough. This is especially useful when the cartridge is almost empty and there may not be enough Symlin left for the dose you want.

Note that once you've pulled back the plunger the only way to undo this is to dispense the dose. If you dial up too small a dose you can choose a larger number and pull the plunger further back. If you've dialed up too much, you need to just dispense the Symlin into the air.

As you push the plunger there are soft clicking noises. I didn't count these, but there seems to be one click for a 15 mcg dose and three or four (I didn't count carefully enough) for a 60 mcg dose.

Once you've started to use the pen, you can store it at room temperature up to 86 degrees F (30 degrees C). Unopened pens must be stored in a fridge.

Overall I think this is going to be a lot easier than carrying around a vial and syringe. I wish the pens themselves weren't disposable, but that seems to be the way these things are made nowadays. I think I'd give the pen design a score of 7 out of 10.

To improve the score Amylin would need to include a pen needle with their samples and reduce the size enough for this to fit in a normal shirt pocket.
I think this will be a useful addition to my diabetes kit.

Update: As I've used the pen I've paid more attention to how it works.

When you press the 'plunger' to deliver there is one click for every 15 mcg. One each click 15 mcg is actually delivered, so it's a chunky delivery. Because of the pH of Symlin (4.0 which makes it acidic), that first click stings a little. After it stops clicking the plunger still has a way to go, but the last part doesn't deliver anything.

Also, when you dial up a quantity and start to pull back the plunger it clicks, again one click for every 15 mcg. If you pull slowly you can count the clicks. This is probably helpful for anyone who has vision problems. Nice design feature Amylin!

Labels: design, symlin, SymlinPen

posted by Bernard @ 9:57 PM