Proton pump inhibitors include-

Esomeprazole, Lansoprazole, Omeprazole, Pantoprazole, Rabeprazole, Pramiprazole Refer - Omeprazole

Proton pump inhibitors causes a profound and long lasting inhibition of gastric acid secretion. Therefore esomeprazole, lanzoprazole , omeprazole ,pantoprazole and rabeprazole, may interfere with the absoption of drugs where gastric pH is an important detreminant of bioavailability ( eg.ketoconazole, ampicillin, iron salts, digoxin, cyanocobalamin )

CYP450 system - There have been reports of interaction between omeprazole and certain drugs metabolized via the CYP450 system ( eg. cyclosporine, disulfram, benzodiazepines ).

Esmoprazole , lansoprazole, pantoprazole, and rabeprazole are extensively metabolised by CYP2C19 and CYP34A . in clinical studies antacids were used conomittantly with these agents The affinity for cytochrome P450 isoenzymes is lower for pantoprazole than omeprazole. Apart from this, pantoprazole appears to have no other clinically significant drug interactions.

Duodenal and gastric ulcer. Reflux osesophagitis

U.S.FDA APPROVED  DRUGS DURING 2004

Most frequently observed adverse reactions during short term administration include - diarrhoea, dizziness, pruritus and skin rash. There are no clinically relevant alterations documented.

Pantoprazole has not shown any significant adverse effects and increase in enterochromatin- like cell (ECL) density during long term (6 mths to 4 years) tolerability in patients with peptic ulcer.

The possibility of GIT infection due to decreased gastric acid secretion should not be ruled out of mind, even though it is not documented.

Hypersensitivity

Special precaution:

Bacterial over growth in the gastrointestinal tract may be possible due to long term elevation of gastric pH. Not recommended for use in children.

Pregnancy and lactation.

Approved 0n  December 1998

Indication-

Duodenal and gastric ulcer. Reflux osesophagitis

Dosage-

Dose of 40mg once daily before breakfast. No dosage adjustment for elderly and in patients with renal or hepatic impairment.

Missed dose-

1. If you miss a dose of this medicine, take it as soon as possible.

2. However, if it is almost time for next dose, skip the missed dose and go back to your regular dosing schedule.

3. Do not double doses.

GASTRO OSEPHAGEAL REFLUX DISEASE (GORD)

Evidence Based Medicine (MIMS- March 2003)

Beneficial

1. Proton Pump Inhibitors such as omeprazole, Lansoprazole, pantoprazole

2. H-2 Antagonists such as cimetidine, ranitidine, famotidine, (less than proton pump inhibitors)

3. Fundoplication

Likely to be beneficial

1. Medical and surgical tretment of GORD in selected patients with extraoesophageal manifestations.

Unknown effectiveness

1. Medical and surgical treatment of GORD in patients with Barrets oesophagus

2. Surgical treatment for non erosive oesophagitis

Key Points

1. One systemic review of randomised clinical trials has found proton inhibitors to be more effective than H-2 antagonists in both erosive and non-erosive oesophagitis. One trial has found no significant differences in the effectiveness of different proton pump inhibitors

2. Surgical treatment has not been adequately evaluated in controlled clinical trials. Medical and surgical treatments have not been adequately compared

3. It is not clear whether patients with Barretts oesophagitis benefit from medical or surgical treatment of their gastro oesophageal reflux

4. There is limited, conflicting evidence on the basis on the benefits of treating gastro oesophageal reflux in patients with extra oesophageal manifestations (such as asthma)

Refer - Omeprazole

Pharmacology:

Pantoprazole is a substituted benzimidazole drug which like omeprazole and lansoprazole cause irreversible inhibition of proton pump function. Consequently, inhibition of gastric acid secretion leading to acid related conditions occurs.

Pharmacokinetics:

Folowing oral administration, pantoprazole is absorbed rapidly with peak plasma concentrations of 1.1 - 3.1mg/L reaching at 2 - 4 hrs after ingestion. It has high plasma protein binding capacity. Even though it has short plasma half- life (0.9 - 1.9 hrs); inhibition of acid secretion once accomplished sustains for a long time.

Bioavailabilty not afffected by cocomittant intake of food.

Pregnancy:

Not recomended during pregnancy and lactation.

Children:

Not recommended for children below 12 years of age.