Lyfnua (Gefapixant)

Lyfnua is used in the management of chronic cough conditions. It is specifically indicated for:

• Chronic refractory cough: Reduces coughing in patients who do not respond to standard treatments.
• Unexplained chronic cough: Alleviates persistent coughing when the underlying cause is unknown.
• Chronic cough in adults: Provides relief for adults suffering from long-term coughing issues.

• Lyfnua works by selectively antagonizing P2X3 receptors in sensory neurons. These receptors are involved in the cough reflex pathway. By blocking the binding of ATP to P2X3 receptors, gefapixant reduces the sensitivity of the cough reflex, thereby decreasing the frequency and intensity of coughing.

Lyfnua may cause several side effects, which can be categorized as follows:

Common Side Effects

• Diarrhea: Frequent bowel movements or loose stools.
• Dyspepsia: Indigestion or discomfort in the upper abdomen.
• Nausea: Feeling of sickness or the urge to vomit.
• Dry mouth: Reduced saliva production in the mouth.
• Increased salivation: Excessive production of saliva.
• Upper abdominal pain: Discomfort or pain in the upper stomach area.
• Upper respiratory infection: Symptoms such as a runny nose, sore throat, or cough.
• Cough: Persistent or worsening cough.
• Oral hypoesthesia: Reduced sensation in the mouth.
• Oral paresthesia: Tingling or numbness in the mouth.
• Ageusia: Loss of taste.
• Dysgeusia: Altered or distorted taste perception.
• Hypogeusia: Reduced taste sensitivity.
• Headache: Pain or discomfort in the head.
• Dizziness: Feeling lightheaded or unsteady.
• Bladder stones: Formation of stones in the bladder.
• Kidney stones: Formation of stones in the kidneys.
• Urinary tract stones: Formation of stones in the urinary tract.
• Insomnia: Difficulty falling or staying asleep.
• Reduced appetite: Decreased desire to eat.

Serious or Rare Side Effects

• Severe allergic reactions: Symptoms such as rash, itching, swelling, severe dizziness, or trouble breathing.

Lyfnua should be used with caution and certain precautions should be observed:

• Allergies: Inform your healthcare provider if you have any known allergies to gefapixant or any of the excipients in Lyfnua.
• Pregnancy: It is best to avoid using Lyfnua if you are pregnant, as its safety during pregnancy has not been established.
• Breastfeeding: Consult your healthcare provider before using Lyfnua while breastfeeding.
• Sleep apnea: Inform your healthcare provider if you have sleep apnea, as Lyfnua may affect your breathing.
• Severe kidney impairment: Use Lyfnua with caution if you have severe kidney impairment and are not undergoing dialysis.
• Storage: Store below 25°C: Keep in the original pack, protect from moisture.

Lyfnua may interact with other medications, which can be categorized as follows:

Major Interactions (Avoid)

• Sulfonamide allergies: Avoid Lyfnua if you are allergic to sulfonamides, as it may cause severe allergic reactions.
• Severe kidney impairment: Avoid use in patients with severe kidney impairment who are not undergoing dialysis.

Moderate Interactions (Monitor Closely)

• Other medications: Inform your healthcare provider about all medications you are taking to avoid potential interactions.
• Sleep apnea: Monitor closely if you have sleep apnea, as Lyfnua may affect your breathing.
• Kidney stones: Monitor for symptoms of kidney stones, such as pain in the back or side, blood in the urine, or painful urination.