Prevacid 401

here you go:

How Stomach Acid Is Produced

Acid is produced by cells in the stomach lining called parietal cells. Inside these cells, the actual production of acid is done by little chemical pumps known as proton pumps. These proton pumps have two states – active (producing acid) and inactive (not producing acid). The pumps are activated when special sensors in the stomach detect that the pH of the stomach fluids have risen to a higher level (less acidic). The main way that this happens is when you eat a meal. They can also be activated by other means, which I will mention later.

Proton Pump Inhibitors

PPIs (proton pump inhibitors) are currently the safest and most effective drugs available for treating gastroesophageal reflux disease (GERD). They work by permanently bonding to and blocking the active proton pumps in the parietal cell, thus preventing them from producing any more acid. Eventually these blocked pumps are sloughed off and new pumps are produced, but while the majority of pumps are blocked, very little acid is produced in the stomach. It is important to remember that PPIs can only block those proton pumps that are in an active state, and any pumps that were not in an active state during the exposure to a PPI will still be able to produce acid later if they are activated.

PPIs are what are known as pro-drugs, which means that when they are taken they are not in an active or working state – they require certain conditions to be activated, specifically they require a very highly acidic environment to be activated. This specific environment is only found right at the site of acid production in the parietal cell, so they do not get activated until they reach the parietal cell. After they are activated they are eliminated from the body very quickly. For these reasons, PPIs do not really affect any other area of the body or produce “side effects” and they are very safe, even in very high doses.

The most recent research has shown that infants and young children metabolize PPIs at a rate 3 times faster than adults. As a result, larger and more frequent doses are usually required in order to achieve therapeutic results in infants and young children. MARCI-Kids recommends TID (three times daily) dosing for any children under the age of 2. For more information, please visit our website: http://www.MARCI-Kids.com.

There are two types of PPIs – DR (delayed release) PPIs and IR (immediate release) PPIs. Prevacid (capsules, Solutabs, powder packets), Prilosec (tablets and capsules), Nexium (tablets and capsules), Aciphex (capsules) and Protonix (capsules) are all DR PPIs. Currently, Zegerid is the only FDA approved IR PPI on the market.

H2RA drugs such as Zantac, Pepcid, Tagamet or Axid should not be administered within 4 hours of a PPI, as they will interfere with the PPI and make it less effective.

How Delayed Release PPIs Work

In their pure and unprotected form, PPIs are very vulnerable to degradation when exposed directly to the acid in the stomach. For this reason, DR PPIs are given an enteric coating. This protective coating is specifically designed not to dissolve while the drug is in the acidic fluids in the stomach, but instead it dissolves when the tablet or granules reach the higher pH (less acidic) environment of the duodenum (the first section of the small intestine). Here the coating dissolves and the drug is absorbed into the blood stream, where it is carried to the parietal cells, where it does its job of blocking proton pumps. This whole process takes 30 minutes to 1 hour.

DR PPIs should be given on an empty stomach because food in the stomach can both lower the level of absorption and raise the pH in the stomach, causing the enteric coating on the drug to dissolve, which then leaves the drug vulnerable to exposure to pockets of acid in the stomach which could destroy the drug.

DR PPIs should be given 30 minutes to 1 hour before a full meal (6 oz or more for infants). As I already mentioned, in order for PPIs to work their best you want as many proton pumps to be in an active state as possible, and the primary way of achieving this is by eating a full meal. The timing is important because you want the meal to be activating lots of proton pumps right at the same time that the drug is reaching peak levels in the blood stream.

DR PPIs should taken with water or sprinkled over an acidic food such as apple sauce or yogurt.

You should never break or crumble a tablet form of DR PPI, as this will compromise the protective enteric coating. (Prevacid Solutabs contain enteric-coated granules within the tablet, and it is ok to break a Solutab in half, as this should not harm the individual granules)

You should never give a DR with a non-acidic food (such as milk, formula or cereal), as this will dissolve the enteric coating and leave the drug unprotected.

DR PPIs should never be chewed or crushed, as this will compromise the protective enteric coating.

For infants, MARCI-Kids recommends the use of the IR PPI Zegerid over DR forms of PPIs, as infants can easily spit out, chew or even choke on the granules of DR PPIs. Of the DR PPIs, Prevacid Solutabs seem to be the easiest to administer for most parents.

How Immediate Release PPIs Work

Rather than use an enteric coating to protect the drug from stomach acid, IR PPI Zegerid accompanies the PPI (omeprazole) with the necessary quantity of buffer (sodium bicarbonate) required to neutralize the acid that is present in the stomach, raising the pH to a level that is safe for the drug. This gives Zegerid several advantages over DR PPIs.

1. The drug can be absorbed directly and immediately into the blood stream, both in the stomach and in the duodenum, and start blocking proton pumps much more quickly.

2. The buffer provides immediate relief from the reflux, acting as an antacid and neutralizing the acid in the stomach and esophagus.

3. The buffer works even more effectively than a meal, turning on more proton pumps in the stomach, which are then blocked by the drug.

4. Since the buffer does the work of a meal in turning on the proton pumps and no enteric coating is involved, Zegerid can be given without regard to mealtime (in-between, before, during, or after meals). The dose can even mixed with a small amount of milk, formula, or rice cereal, provided that the child can finish the dose in one sitting. (Zegerid should not be mixed with acidic foods such as applesauce, yogurt or juice)

5. The liquid form of Zegerid – Zegerid Powder for Oral Suspension – is a stable, true homogeneous liquid suspension, which is very easy to split up into exact individual doses and administer to infants and children.

nataliachick72007-4-19 10:8:13

My favourite site to describe this (in more detail then you ever wanted to know!) is http://www.ppiknow.com . They describe all the PPIs and exactly how they work and what the med is doing at various intervals in time. Very interesting for a science geek like me… definitely a thorough description.

BTW, I’m obsessed too!