Flosin - Dosage | Overdose | Side Effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Flosin modified-release capsules contain tamsulosin as an active ingredient. It belongs to a group of medicines called alpha-1 adrenergic antagonists. This medicine is only applied in the treatment of prostate disorders.

Mechanism of action

Flosin binds selectively and competitively to postsynaptic alpha-1 adrenergic receptors (especially to subtypes alpha-1A and alpha-1D), which are responsible for relaxing the muscles of the prostate, thereby reducing the prostate tension. By reducing prostate tension, this medicine facilitates the flow of urine and thus facilitates urination (the main symptom of prostate enlargement is difficult urination).

During clinical studies, the effect of this drug on blood pressure was not observed (lowering blood pressure is the main characteristic of most drugs used in the treatment of prostate enlargement).

When you need to be careful with using Flosin?

It should not be applied if you have any of the following conditions:

  • Allergy to tamsulosin or other Flosin ingredients
  • Orthostatic hypotension
  • Liver insufficiency
  • Severe renal impairment (if creatinine clearance is less than 10 ml / min)

It also should not be used in patients planning cataract surgery.


Take one capsule per day after the first meal in the day.

Swallow the capsule whole. Do not crush or crumble it because it will affect the modified release of the active ingredient of this drug.

Tolerance to this drug rarely occurs (i.e. the phenomenon that over time, the same dose has less effect), and this medication can be used for long-term treatment (treatment may last over six years).


Flosin overdose can lead to potentially serious reduction in blood pressure.

If overdose occurs, treatment should be symptomatic. The patient should be placed in the supine position and, if this does not normalize the heartbeat, then plasma expanders and vasopressors should be applied. Monitoring of renal function should also be conducted.

Dialysis will not help because Flosin binds to plasma proteins.

It is also useful to induce vomiting, gastric lavage and activated charcoal.

Do not take more than one capsule a day.


Co-administration with the following drugs should be avoided:

  • Drugs that are inhibitors of an enzyme called phosphodiesterase 5 - drugs that are used to increase libido and to treat erectile dysfunction, such as: sildenafil (Viagra). Interaction with another drug used for erectile dysfunction which is called tadalafil (also known as Cialis) revealed no interaction with Flosin.1
  • Diclofenac - a drug used to relieve pain. Diclofenac may increase the degree of elimination of Flosin and thus reduce its efficiency.
  • Warfarin.
  • Ketoconazole, itraconazole, voriconazole and posaconazole - drugs used for fungal infections. These drugs increase the concentration of Flosin and increase the risk of side effects.
  • Clarithromycin, telithromycin - medicines used to treat a number of infections (macrolide antibiotic). It can increase the effect of Flosin and cause side effects.
  • HIV protease inhibitors (drugs used to treat HIV infection), such as:
    • amprezanavir
    • ritonavir
    • indinavir
    • atazanavir and others.
    These drugs increase the effect of Flosin which can lead to hypotension.
  • Tizanidine - a drug that is used for muscle stiffness. This drug can lower blood pressure as well as Flosin, and simultaneous use is not recommended.

Flosin side effects

The most common reported side effects are:

  • Rhinitis
  • Pharyngitis
  • Abnormal ejaculation (occurring in 8.3% of patients)
  • A sudden, transient loss of consciousness due to impaired brain perfusion (occurring in 1.7% of patients)
  • Low blood pressure (occurring in 1.3% of patients)2
  • Priapism

This drug is well tolerated and it's rare that treatment must be discontinued due to its side effects. You may experience mild side effects that will quickly disappear.

This drug has an excellent safety profile.


  1. NCBI link 1
  2. NCBI link 2

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