(e:Paul),
(e:Terry) and I were discussing the relative merits of Claritin (Loratadine) in comparison with Benedryl (Diphenhydramine) in combating symptoms of allergy. Apart from remembering that Benedryl is a 1st generation antihistamine and that Loratadine is a 2nd generation antihistamine, I was sorry to note that I remembered nothing more about their pharmacology or specifics of how they differed from each other in their mechanism of action.
What follows is a dry account of the differences. Well... maybe not so dry because I am interested. :-)
Any allergic episode has two components: the early and late component. The early component is when the immunoglobulins (type E) recognize allergens, interact with the foot-soldier cells of the immune system. This interaction promotes the release of histamine, prostaglandins and leukotrienes from granules within not only mast cells, but also basophils, lymphocytes, and other reservoirs. Histamine then binds to receptors on nerves and blood vessels and leads to sneezing, tearing up, congestion and whatnots. Antihistamines compete with histamine for spots on the receptor and thus competitively reduce or completely block its action.
1st generation drugs such as diphenhydramine (Benedryl) also have additional anticholinergic, anti-serotonin, local anaesthetic, as well as sedative effects that might either provide a broader spectrum of relief from allergies or might just end up giving people more side effects (which explains the trippy experience I had.)
The late component of allergy is a plain inflammation reaction in the tissues mediated by immune cells called T-helper cells type-2 (Th2) and a host of cytokines (hormones/signalling molecules of the immune system). The inflammatory component feels exactly like a cold with the same reactions. In addition, the inflammatory component primes the immune response or "sensitizes" the immune system to even swifter allergy-induction in response to future allergens.
Loratadine (Claritin) not only binds to the histamine receptor, it also prevents the release of histamine as well as prostaglandins from mast cells - thus preventing "mast cell activation". Loratadine also has some effect on Th2 cells and suppresses some of the later inflammatory phase. It decreases the production of some of the late-phase cytokines. So it's not just an antihistamine. It also has none of the other wider receptor blocking effects of 1st gen antihistamines.
If you are inclined to read the nitty-gritties or how Loratadine acts on the immune system, here's a good review:
::READ PDF::
Oh man, there is always a catch! Back in the day they cooked in stone pots over the fire and their food turned out delicious. Maybe I can get one of those rocks from the Niagara Gorge and have people who are frustrated whack sundry stuff over it till it gets to a shape of a pot? I can then just attach a crowbar as a handle and et voilà ! $450 fry pan!
I wouldn't get it cause of the handle, otherwise it looks pretty good. It looks so awkward to handle because it has no grip, I confirmed it after reading this review:
"This is a good quality pan and is heavy and sturdy. My only complaint is that the silicone sleeve isn't long enough over the handle. My hand has to hold the metal part also, to balance the heavy pan, and it is not comfortable at all. The handle is very thin and rough to the touch. Otherwise, the pan cooks food very quickly and cleans up well."
It might be worth spending some extra money if you can find something similar with a handle of more substance.