VPRAZ* 10/20

COMPOSITION:

Vpraz* 10                                                                     

Each film coated tablet contains: Vonoprazan Fumarate equivalent to Vonoprazan 10 mg           

Vpraz* 20

Each film coated tablet contains: Vonoprazan Fumarate equivalent to Vonoprazan 20 mg        

Clinical pharmacology:

Mechanism of Action

Vonoprazan is a potassium-competitive acid blocker (PCAB) that reversibly inhibits H⁺,K⁺-ATPase without requiring acid activation. As a strong base, it binds tightly to the gastric acid pump, effectively suppressing acid secretion.

Pharmacokinetics:

Absorption

Absolute bioavailability has not been determined. The pharmacokinetic parameters of vonoprazan following single administration of vonoprazan to healthy adult male subjects at 20 mg under fasting  shows:- tmax,ss(h)-1.5(1.0,3.0), Cmax,ss(ng/mL)- 24.3±6.6, t1/2Z (h)- 7.7±1.0, AUC48(h ng/mL)- 222.1±69.7 where as after meal shows-: tmax,ss(h)- 3.0 (1.0, 4.0), Cmax,ss(ng/mL)- 26.8±9.6, t1/2Z (h)- 7.7±1.2, AUC48(h ng/mL)- 238.3±71.1

Distribution

The mean binding rate is 85.2 to 88.0% when vonoprazan in the range of 0.1to 10 μg/mL is added to human plasma (in vitro).

Metabolism

Vonoprazan is primarily metabolized by the liver enzyme CYP3A4, with minor contributions from CYP2B6, CYP2C19, CYP2D6, and the sulfotransferase SULT2A1.

 (In vitro). Vonoprazan shows a time-dependent inhibition of CYP2B6, CYP2C19, and CYP3A4/5 in vitro. It also exhibits a mild, concentration-dependent induction of CYP1A2, with minimal inductive effects on CYP2B6 and CYP3A4/5.

Excretion and Elimination

Following oral administration of radiolabeled vonoprazan (15 mg) to healthy adult males, 98.5% of the dose is excreted within 168 hours—67.4% via urine and 31.1% via feces.

Therapeutic indications:

1. Gastric ulcer, duodenal ulcer, reflux esophagitis, prevention of recurrence of gastric or duodenal ulcer during low-dose aspirin administration, prevention of recurrence of gastric or duodenal ulcer during non-steroidal anti-inflammatory drug (NSAID) administration.

2. Adjunct to Helicobacter pylori eradication in the following settings: Gastric ulcer, duodenal ulcer, gastric mucosa-associated lymphatic tissue (MALT) lymphoma, idiopathic thrombocytopenic purpura, the stomach after endoscopic resection of early stage gastric cancer or Helicobacter pylori gastritis.

Dosage and administration:

Gastric ulcer and duodenal ulcer

The usual adult dosage for oral use is 20 mg of Vonoprazan administered orally once daily an 8 week treatment for gastric ulcer and a 6 week treatment for duodenal ulcer.

Reflux esophagitis

The usual adult dose for oral use is 20 mg of Vonoprazan administered once daily for a total of 4 weeks of treatment. If that dosing proves insufficient, the administration should be extended, but for no longer than 8 weeks of treatment.

For the maintenance therapy of reflux esophagitis showing recurrence and recrudescence, the dose for oral use is 10 mg of Vonoprazan once daily. However, when the efficacy is inadequate, the dosage may be increase up to 20 mg of Vonoprazan once daily.

Prevention of recurrence of gastric or duodenal ulcer during low-dose aspirin administration

The usual adult dosage is one tablet of 10 mg of Vonoprazan administered once daily.

Prevention of recurrence of gastric or duodenal ulcer during non-steroidal anti-inflammatory drug (NSAID) administration

The usual adult dosage is one tablet of 10 mg of Vonoprazan administered once daily

Warnings and Precautions

Vonoprazan should be used at the minimum effective dose based on the patient’s condition, with close monitoring and periodic evaluation (e.g., endoscopy) during long-term use. For reflux esophagitis, maintenance therapy is recommended only for patients with frequent recurrence. It should be avoided in those who do not need ongoing treatment. If healing is sustained and recurrence risk is low, consider reducing the dose from 20 mg to 10 mg or discontinuing treatment.

Adverse reactions:

Gastrointestinal disorders: Nausea, abdominal distension                                             

Laboratory findings: Elevated γ-GT, AST, ALT; abnormal liver function tests                      

Immune system disorders: Drug hypersensitivity (including anaphylactic shock), drug eruption, urticaria                                                                Hepatobiliary disorders: Hepatotoxicity, jaundice 

Skin and subcutaneous disorders: Rash, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis

Drug interactions:

Vonoprazan should be administered with care when co-administered with the following drugs:

CYP3A4 inhibitors, Clarithromycin etc. Blood conc. of Vonoprazan may increase.

Digoxin, Methyldigoxin: Effect of these drugs may be enhanced.

Itraconazole, Tyrosine kinase inhibitors Gefitinib, Nilotinib, Erlotinib: Effect of these drugs may be diminished.

Use in specific population:

Pregnancy

No clinical studies have evaluated vonoprazan in pregnant women. As a precaution, it should only be used during pregnancy if the potential benefits outweigh the possible risks.

Breast-feeding

No clinical studies have assessed vonoprazan use during lactation. If treatment is necessary, breastfeeding should be avoided.

Contraindications

Hypersensitivity to the active ingredients or to any of the excipients.

Overdosage

There is no reported experience of vonoprazan overdose. It is not removed by hemodialysis. In case of overdose, treatment should be symptomatic and supportive. Vonoprazan has no known potential for abuse or dependence.

Storage

Store protected from light and moisture at a temperature not exceeding 30°C.

Presentation

Vpraz* 10/20 : Inner Carton containing 3 Alu-Alu blister strips of 10 tablets. Such 5 inner cartons are packed in outer carton.