Solixa-Xantis

Solixa-Xantis (Solifenacin) is a medicine used to treat symptoms of overactive bladder (OAB). OAB is characterized by symptoms such as frequent urination, a strong and sudden urge to urinate (urgency), and urinary incontinence due to urgency.

Solifenacin is an antimuscarinic (anticholinergic) agent that works by blocking muscarinic receptors in the bladder. This leads to relaxation of the detrusor muscle of the bladder, reducing the frequency and force of bladder contractions and improving the ability to control urination.

Indications Solixa-Xantis

1. Frequent urination: Increased frequency of urination during the day and at night (pollakiuria).
2. Urgency: A strong and sudden urge to urinate that is difficult to control.
3. Urge urinary incontinence: Involuntary loss of urine resulting from an urgent urge to urinate.

Release form

Tablets: Solixa-Xanthis is available as oral tablets, which typically come in 5 mg and 10 mg strengths of solifenacin succinate.

Pharmacodynamics

1. Muscarinic receptor antagonism: Solifenacin blocks muscarinic cholinergic receptors in various organs and tissues, such as the bladder, which leads to a decrease in the activity of the cholinergic system.
2. Reducing bladder contractions: Blocking bladder muscarinic receptors with solifenacin reduces spontaneous bladder contractions and increases bladder capacity, which may help reduce frequency and force of urination.
3. Improving symptoms of urinary incontinence: Using solifenacin can reduce symptoms of urinary incontinence, such as frequent, involuntary, or the feeling of having to go to the toilet frequently.
4. Improving Bladder Function: Blocking muscarinic receptors may also improve bladder function in patients with overactive bladder, helping them to better control their urinary functions.
5. Reducing smooth muscle spasms: Solifenacin may also have an antispasmodic effect on the smooth muscles of the bladder, which helps relax the bladder and reduce spasms.

Pharmacokinetics

1. Absorption:

   • After oral administration, solifenacin is well absorbed from the gastrointestinal tract.
   • The maximum plasma concentration is reached approximately 3-8 hours after administration.
   • Bioavailability is about 90%.

2. Distribution:

   • The volume of distribution of solifenacin is approximately 600 liters.
   • The drug binds to plasma proteins by 98%, mainly with albumin and acidic alpha1-glycoproteins.

3. Metabolism:

   • Solifenacin is extensively metabolized in the liver with the participation of the enzyme CYP3A4.
   • Major metabolites include 4R-hydroxylated and N-glucuronidated compounds.

4. Excretion:

   • The half-life of solifenacin is approximately 45-68 hours.
   • Approximately 70% of the administered dose is excreted in the urine, of which about 11% as unchanged substance and 18% as the N-glucuronide metabolite.
   • About 23% of the dose is excreted in the feces.

5. Special populations:

   • In elderly patients, as well as in patients with impaired liver or kidney function, the pharmacokinetics of solifenacin may change, which may require dosage adjustment.

Dosing and administration

Recommended dosage:

1. Initial dose:

   • It is usually recommended to start with a dosage of 5 mg once daily.

2. Maintenance dose:

   • If necessary and if the drug is well tolerated, the dose can be increased to 10 mg once a day.

Method of application:

• Tablets are taken orally with plenty of water.
• Time of administration: Tablets can be taken regardless of meals.
• Regularity: The drug is taken once a day, preferably at the same time every day to maintain a stable level of the drug in the body.

Special instructions:

• Missed dose: If you miss a dose, take it as soon as possible. If it is already time for your next dose, do not take a double dose to make up for the missed dose. Just continue taking it as usual.
• Overdose: In case of overdose, seek medical help immediately.

Use Solixa-Xantis during pregnancy

Using Solix-Xantis during pregnancy is not recommended because there is no convincing evidence of its safety for the fetus. Here are the main points from the available studies:

1. A study of the pharmacokinetic interaction of solifenacin with oral contraceptives showed that solifenacin does not affect the pharmacokinetics of ethinyl estradiol and levonorgestrel, which may be relevant when used during reproductive age. However, this study did not examine the safety of solifenacin during pregnancy itself (Taekema-Roelvink et al., 2005).
2. The efficacy and safety study of post-vomiting dribbling in women found no significant differences between solifenacin and placebo. The study did not include a specific population of pregnant women, and data on the safety of solifenacin during pregnancy remain limited (Ablove et al., 2018).

Based on the lack of data on the safety of solifenacin during pregnancy, it is important to consult a doctor before using it to assess any potential risks to fetal development.

Contraindications

1. Hypersensitivity: People with a known hypersensitivity or allergic reaction to solifenacin or any other components of the drug should avoid its use.
2. Severe renal impairment: The drug is not recommended for use in patients with severe renal impairment (creatinine clearance
3. Severe hepatic impairment: Solifenacin is contraindicated in patients with severe hepatic impairment (Child-Pugh class C).
4. Angle-closure glaucoma: The drug is not recommended for use in patients with uncontrolled angle-closure glaucoma due to the risk of increased intraocular pressure.
5. Myasthenia gravis (myasthenia gravis): Solifenacin may worsen the symptoms of myasthenia gravis and is therefore contraindicated in this disease.
6. Acute urinary retention: The drug is contraindicated in patients with acute urinary retention as it may worsen the condition.
7. Gastrointestinal obstruction: The drug is contraindicated in patients with gastrointestinal obstruction, including toxic megacolon and paralytic ileus.
8. Severe gastroparesis: The drug should not be used in patients with severe gastroparesis (delayed gastric emptying).

Side effects Solixa-Xantis

1. Very common side effects (more than 10%):

   • Dry mouth.

2. Common side effects (1-10%):

   • Constipation.
   • Nausea.
   • Dyspepsia (indigestion).
   • Stomach pain.
   • Dry eyes.
   • Blurred vision.
   • Rapid heartbeat (tachycardia).
   • Fatigue.

3. Infrequent side effects (0.1-1%):

   • Urinary tract infections.
   • Difficulty urinating (eg, urinary retention).
   • Urine retention.
   • Dry skin.
   • Feeling of thirst.
   • Visual disturbances, including blurred vision.
   • Drowsiness.
   • Dizziness.
   • Sinusitis.

4. Rare side effects (0.01-0.1%):

   • Anaphylactic reactions.
   • Allergic reactions such as skin rash or itching.
   • Angioedema.
   • Confusion.
   • Hallucinations.
   • Heart rhythm disturbances (eg, QT prolongation, arrhythmias).

5. Very rare side effects (less than 0.01%):

   • Psychiatric disorders (eg, anxiety, depression).
   • Convulsions.
   • Worsening of glaucoma symptoms.

Overdose

1. Anticholinergic effects: Such as dry mouth, constipation, urinary retention, mydriasis (dilated pupils), dry skin and flushing, tachycardia, increased heart rate.
2. Central effects: Headache, dizziness, agitation, confusion, hallucinations, drowsiness.
3. Serious complications: In severe overdose, seizures, coma, respiratory depression and cardiovascular complications may develop.

Overdose treatment

Treatment of overdose with solifenacin is usually aimed at relieving symptoms and supporting vital functions:

1. Activated charcoal: Taking activated charcoal may help reduce absorption of the drug from the gastrointestinal tract if a short time has passed since ingestion.
2. Rinsing stomach: May be useful in case of recent ingestion of a large amount of the drug.
3. Symptomatic therapy: Maintenance of respiratory and cardiovascular functions. This may include intravenous fluids, blood pressure support, and cardiac monitoring.
4. Antidotes: In severe cases of anticholinergic symptoms, physostigmine may be prescribed under medical supervision.
5. Hospitalization: In severe cases, hospitalization for intensive observation and treatment may be required.

Interactions with other drugs

1. CYP3A4 inhibitors: Drugs that inhibit the CYP3A4 enzyme (eg, ketoconazole, itraconazole, ritonavir, clarithromycin) may increase the blood concentration of solifenacin, which may increase its side effects.
2. CYP3A4 inducers: Drugs that induce the CYP3A4 enzyme (eg, rifampicin, phenytoin, carbamazepine) may decrease the blood concentration of solifenacin, which may reduce its effectiveness.
3. Anticholinergics: Concomitant use with other anticholinergics (eg, atropine, scopolamine, some antidepressants and antipsychotics) may increase anticholinergic side effects such as dry mouth, constipation, blurred vision, and difficulty urinating.
4. Drugs that prolong the QT interval: Concomitant use with drugs that prolong the QT interval (eg, class IA and III antiarrhythmic drugs, some antidepressants and antipsychotics) may increase the risk of cardiac arrhythmias.
5. Drugs that alter GI motility: Drugs that alter GI motility (eg, metoclopramide) may affect the absorption of solifenacin.
6. Antihistamines: Some antihistamines may enhance the anticholinergic effects of solifenacin.
7. Medicines that change gastric pH: Antacids and other drugs that change gastric pH may affect the absorption of solifenacin.