Sonirid Duo
Before starting therapy with Soniride Duo, it is necessary to examine the patient to exclude other diseases that are characterized by symptoms reminiscent of BPH. Before starting treatment and regularly during therapy, it is necessary to perform a digital rectal examination of the prostate gland, and, if necessary, a PSA determination.
Precautions when using tamsulosin:
As with other alpha-1 adrenergic blockers, blood pressure may decrease during treatment with tamsulosin, which in rare cases can lead to fainting. At the first signs of orthostatic hypotension (for example, dizziness, weakness), the patient should be seated or laid down until symptoms disappear completely.
Particular caution should be exercised when treating patients with end-stage renal disease (creatinine clearance less than 10 ml/min), since the use of tamsulosin has not been studied in this patient population.
During surgery for cataracts or glaucoma, some patients taking tamsulosin (at the time of surgery or earlier) developed intraoperative iris instability syndrome (a type of small pupil syndrome). When this syndrome occurs, the risk of complications during surgery and in the postoperative period increases. It is not recommended to prescribe tamsulosin to patients who are planning surgery for cataracts or glaucoma. It is advisable to discontinue tamsulosin 1-2 weeks before surgery; however, the benefit and duration of discontinuation of tamsulosin treatment before cataract surgery have not been determined. There are known cases of the development of intraoperative iris instability syndrome in patients who discontinued tamsulosin earlier before surgery. During the preoperative evaluation, the operating surgeon and members of the ophthalmic team should consider whether the patient is (or has previously been) taking tamsulosin. This is necessary to prepare for the possible occurrence of the syndrome during surgery. Tamsulosin should be used with caution in combination with strong and moderate inhibitors of the CYP3A4 isoenzyme.
Tamsulosin and active inhibitors of the CYP3A4 isoenzyme (for example, ketoconazole) should not be used in slow metabolizers of the CYP2D6 isoenzyme.
Precautions when using finasteride:
Are common
To avoid obstructive complications, it is necessary to carefully monitor patients with a large volume of residual urine and a sharp decrease in urine flow rate. It is necessary to evaluate the possibility of surgical intervention.
Effect of finasteride on PSA and diagnosis of prostate cancer (PCa) The clinical effectiveness of finasteride at a dose of 5 mg in patients with prostate cancer has not been established. Before starting treatment with finasteride, as well as during subsequent therapy, digital rectal examination of the prostate and other tests should be performed regularly to exclude prostate cancer. Serum PSA is also used to diagnose prostate cancer. As a rule, if initial PSA values are above 10 ng/ml, further examination and biopsy are indicated; if initial PSA values are between 4 and 10 ng/ml, additional testing is recommended.
In men, PSA values can vary widely, regardless of the presence of prostate cancer. Thus, normal PSA values do not rule out prostate cancer in men with BPH, regardless of treatment with finasteride 5 mg. If the initial PSA value is below 4 ng/ml, prostate cancer cannot be excluded either.
In patients with BPH, the use of finasteride at a dose of 5 mg reduces the concentration of PSA in the blood serum by approximately 50%, even in the presence of prostate cancer. This fact must be taken into account when assessing the PSA value in patients with BPH receiving treatment with finasteride, since a decrease in PSA concentration is not a basis for excluding concomitant PCa. A decrease in PSA concentration is expected in any range of values, but there are individual differences. In patients receiving finasteride 5 mg for 6 months or longer, the obtained PSA value should be doubled before comparing it with normal values. The use of this correction allows us to maintain the sensitivity and specificity of the PSA test, and take the result into account when diagnosing prostate cancer.
If there is a persistent increase in PSA concentration in patients receiving finasteride at a dose of 5 mg, an examination should be carried out. In this case, a possible violation of the treatment regimen by the patient cannot be ruled out.
Impact on laboratory results
Effect on PSA
Serum PSA concentration correlates with patient age and prostate volume, and prostate volume correlates with patient age. When interpreting the result of a PSA laboratory test, it must be taken into account that in patients receiving finasteride at a dose of 5 mg, a decrease in PSA levels is observed. Most patients experience a rapid decline in PSA levels during the first months after starting treatment, then its concentration stabilizes at a new level. The PSA value after treatment is approximately half the value obtained before the start of therapy. Thus, in patients receiving finasteride 5 mg for six months or longer, the obtained PSA value should be doubled before comparing it with normal values.
Finasteride at a dose of 5 mg does not significantly reduce the proportion of free PSA (the ratio of free PSA to total). The ratio of free PSA to total remains unchanged even when taking finasteride at a dose of 5 mg. When determining the proportion of free PSA for the diagnosis of prostate cancer, no correction of values is required.
Breast cancer in men
During clinical trials and post-marketing, cases of breast cancer have been reported in men taking finasteride 5 mg. The specialist should warn the patient to immediately report any changes in the mammary glands (tightness, pain, gynecomastia or nipple discharge).
Mood changes
Mood changes, including depression and suicidal ideation, have been observed in patients taking finasteride 5 mg. It is necessary to monitor the appearance of psychopathological symptoms, and if they appear, the patient should be referred for consultation with a specialist.
Liver failure
Studies of changes in the pharmacokinetics of finasteride in liver failure have not been conducted.
