Interactions
Due to its effect of reducing stomach acidity, use of pantoprazole can affect absorption of drugs that are pH-sensitive, such as ampicillin esters, ketoconazole, atazanavir, iron salts, amphetamine and mycophenolate mofetil.Additional medications that are affected include bisphosphonate derivatives, fluconazole, clopidogrel, and methotrexate. Pharmacology
The mechanism of action of pantoprazole is to inhibit the final step in gastric acid production. In the gastric parietal cell of the stomach, pantoprazole covalently binds to the H+/K+ ATP pump to inhibit gastric acid and basal acid secretion. The covalent binding prevents acid secretion for up to 24 hours and longer.Pantoprazole is metabolized in the liver by the cytochrome P450 system. Metabolism mainly consists of demethylation by CYP2C19 followed by sulfation. Another metabolic pathway is oxidation by CYP3A4. Pantoprazole metabolites are not thought to have any pharmacological significance. It is usually given with a prokinetic drug because of inactivity in the acidic environment of the stomach. Pantoprazole binds irreversibly to H+K+ATPase (proton pumps) to suppress the secretion of acid. Due to irreversible binding of the pumps, new pumps have to be made before acid production can be resumed. The drugs plasma half-life is about two hours. After administration, the time for the drug to reach peak plasma concentrations is 2 to 3 hours. The percentage of the drug that is protein bound is 98%.In veterinary medicine, pantoprazole appears to be safe to use in several large animal species.
Inappropriate sinus tachycardia (IST) is a rare type of cardiac arrhythmia within the category of supraventricular tachycardia (SVT). IST may be caused by the sinus node itself having an abnormal structure or function, or it may be part of a problem called dysautonomia, a disturbance and/or failure of the autonomic nervous system. Research into the mechanism and etiology (cause) of inappropriate sinus tachycardia is ongoing. IST is viewed by most to be a benign condition in the long-term. Symptoms of IST, however, may be distracting and warrant treatment. The heart is a strong muscle and typically can sustain the higher-than-normal heart rhythm, though monitoring the condition is generally recommended. The mechanism and primary etiology of inappropriate sinus tachycardia has not been fully elucidated. An autoimmune mechanism has been suggested, as several studies have detected autoantibodies that activate beta adrenoreceptors in some patients. The mechanism of the arrhythmia primarily involves the sinus node and peri-nodal tissue and does not require the AV node for maintenance. Treatments in the form of pharmacological therapy or catheter ablation are available, but the condition is currently difficult to treat successfully. Symptoms
Symptoms reported by patients vary in frequency and severity. They may include:

Frequent or sustained palpitations
Dyspnea (shortness of breath) and palpitations on exertion
Pre-syncope (feeling as if about to faint)
Fatigue
Dizziness
Exercise intolerance
Occasional paresthesia and cramping
Symptoms associated with autonomic nervous system disturbance, including gastrointestinal disturbance

Diagnosis
No formal diagnostic criteria exist.