Jinarc 45mg+15mg Tablet

Jinarc 45mg+15mg Tablet contains tolvaptan, a selective vasopressin V2-receptor antagonist, supplied as a split-dose regimen of 45mg taken in the morning and 15mg taken 8-9 hours later in the afternoon. It is indicated to slow the progression of kidney cyst growth and decline in kidney function in adults with autosomal dominant polycystic kidney disease (ADPKD) who have rapidly progressing disease.

Tolvaptan works by blocking vasopressin from binding to V2 receptors in the kidney’s collecting ducts. In ADPKD, vasopressin signalling through these receptors drives fluid accumulation within kidney cysts and promotes cyst cell proliferation; blocking this pathway reduces cyst growth and the associated decline in kidney function, while also producing a marked aquaretic (water-excreting) effect.

By antagonising the V2 receptor, tolvaptan prevents the kidney’s collecting ducts from concentrating urine and reduces the intracellular signalling (cyclic AMP) that drives fluid secretion into cysts and abnormal cyst-lining cell growth. This mechanism directly targets the underlying process of cyst enlargement in ADPKD, rather than simply treating high blood pressure or kidney failure once they occur.

Swallow each Jinarc 45mg+15mg Tablet tablet whole with water, with or without food. Take the morning dose as soon as you wake and the afternoon dose roughly 8 hours later; avoid taking the second dose too close to bedtime as it will increase night-time urination. It is essential to drink water regularly throughout the day, including keeping water accessible overnight, to replace the large fluid losses this medicine causes and to prevent dehydration.

Jinarc 45mg+15mg Tablet is taken as 45mg immediately on waking, followed by 15mg about 8 hours later (for example, on waking and again at around lunchtime, avoiding bedtime dosing so sleep is not disrupted by excessive urination). This split-dose combination is one of several dose levels used during a gradual up-titration that your nephrologist manages based on your tolerability and regular liver and electrolyte monitoring – never adjust your dose without your doctor’s instruction.

Use this product before the expiry date stated on the packaging. Do not use the medicine if the expiry date has passed.

Store below 30°C in a dry place, away from direct sunlight and out of reach of children.

• Excessive thirst
• Very frequent or increased volume of urination (polyuria), including at night
• Dry mouth
• Fatigue or dizziness, which can occur with dehydration or low blood pressure
• Serious: yellowing of the skin/eyes, dark urine, unusual tiredness, or right upper abdominal pain (possible liver injury) require you to stop the medicine and contact your doctor immediately

• Known hypersensitivity to tolvaptan or any ingredient in this product
• Inability to sense or respond to thirst
• Hypovolaemia (low blood volume/dehydration)
• Elevated liver enzymes or signs/symptoms of liver injury, or a prior history of significant liver injury with tolvaptan
• Urinary tract obstruction that prevents passing urine
• Concomitant use with strong CYP3A inhibitors (e.g. ketoconazole, clarithromycin, ritonavir)
• Pregnancy and breastfeeding

• Strong CYP3A4 inhibitors (e.g. ketoconazole, itraconazole, clarithromycin, ritonavir) substantially raise tolvaptan blood levels and must not be combined
• Strong CYP3A4 inducers (e.g. rifampicin, carbamazepine, St John’s Wort) can reduce tolvaptan’s effectiveness
• Grapefruit juice can increase tolvaptan levels and should be avoided
• Other medicines that raise blood sodium, or diuretics, may add to the aquaretic and dehydration effects – inform your doctor of all medicines and supplements you are taking

• This medicine must only be prescribed and monitored by a nephrologist/specialist experienced in ADPKD care
• Attend every scheduled liver function blood test – regular monitoring is mandatory because of a known risk of liver injury, particularly in the first 18 months of treatment
• Drink water proactively throughout the day and keep water within reach overnight to offset the large increase in urine output
• Do not restrict fluids to reduce urination frequency, as this increases the risk of dehydration
• Seek urgent medical attention for jaundice, dark urine, severe fatigue, or abdominal pain