Lifnua, jointly developed by Kyolin Corporation of Japan and Merck of the United States, is the world's first selective P2X3 receptor antagonist.

1. Drug name and main ingredients

Common name: Gefapixant

Product Name: LIFNUA ® (リフヌア ®)

Dosage form: Film coated tablets

Main ingredients: Gefapixant Citrate, each tablet contains 45mg of Gefapixant citrate

Accessories: Crystalline cellulose, D-mannitol, hydroxypropyl methylcellulose, cross-linked polyvinylpyrrolidone, light anhydrous silicic acid, sodium stearoyl fumarate, magnesium stearate, titanium oxide, glyceryl triacetate, ferric oxide, Brazilian palm wax

2. Indications

Difficult to treat chronic cough: used to treat chronic cough that lasts for more than 1 year and cannot be relieved after sufficient etiological treatment (such as asthma, gastroesophageal reflux, etc.).

Restriction: Use only after excluding other clear causes (such as pulmonary organic diseases), which is considered symptomatic treatment.

3. Specifications and characteristics

Specification: 45mg/tablet (10 tablets x 10 boards/box)

Appearance: Round pink film coated piece, with a diameter of about 10.4mm, a thickness of about 5.3mm, a mass of about 463.5mg, and an identification code "777" printed on the surface.

4. Usage and dosage

Conventional dose: 45mg per dose for adults, taken orally twice a day.

Severe kidney injury (eGFR<30mL/min): adjusted to 45mg once daily (without dialysis).

Missed dose: Take it as soon as possible, skip if it is close to the next dose, and do not double the dose.

Diet: Can be taken before or after meals, food has no significant effect.

5. Dose adjustment

Renal injury (eGFR30-90): No adjustment required, but regular monitoring of renal function is necessary.

Severe kidney injury (eGFR<30): reduce to 45mg once daily; There is no recommended dosage for dialysis patients.

Liver dysfunction: No need for adjustment (mainly excreted through the kidneys).

6. Medication precautions

Monitoring requirements: Regularly check kidney function (especially in elderly people), taste function, and urine (be alert to urinary tract crystallization).

PTP packaging: The tablets need to be taken out to avoid swallowing aluminum foil and causing esophageal damage.

Symptomatic treatment: It is necessary to continuously investigate the cause of cough and avoid long-term blind medication.

7. Medication for special populations

Pregnant women: Use only when the benefits outweigh the risks (animal tests show a decrease in fetal weight).

Breastfeeding period: Suspend breastfeeding (animal experiments show milk migration).

Children: Safety has not been established for those under 18 years old.

Elderly people: The dosage should be adjusted according to kidney function (renal excretory drugs).

8. Adverse reactions

Common (≥ 5%): Taste abnormalities (63.1%, such as bitterness and metallic taste), nausea (3.7%), diarrhea (3.8%), and upper abdominal pain (3.0%).

Serious but rare:

Urinary tract stones (0.8/100 person years, related to drug crystallization).

Taste disorders (mostly occurring within 9 days, reversible upon discontinuation of medication).

9. Contraindications

(1) Individuals who are allergic to gemcitabine or sulfonamide drugs (including cross allergy risk).

(2) Individuals with active liver disease or persistent elevation of liver enzymes for unknown reasons (caution should be exercised when using statins in combination).

10. Drug interactions

Bile acid chelators (such as colexamide): need to be taken every 2 hours (before) or 4 hours (after).

CYP inhibitors/inducers: No significant interaction (gefapi metabolism is CYP independent).

MATE/OATP transporter substrates: Low theoretical risk, no need for clinical adjustment (such as omeprazole, pitavastatin).

11. Storage method

Unopened: Store at room temperature (15-30 ° C), avoid moisture, and have a shelf life of 48 months.

After preparation: No preparation required, take orally directly.

12. Manufacturer

Manufacturer: Kyorin Pharmaceutical Co., Ltd. (Japan).

Lifnuainformation