Silodosin (Oral)

Belonging to the class of medications known as alpha blockers, Silodosin works to relieve the symptoms associated with enlargement of the prostate by causing a relaxation of the muscles of the prostate and the bladder.


Silodosin is a medication which is commonly used to treat males suffering from the symptoms associated with an enlarged prostate. These symptoms can include painful urination, incomplete urination, dribbling, more frequent urination, and weak-stream urination. It works not by shrinking the prostate itself, but by relaxing the muscles of the prostate and the bladder so that complete urination can occur.

The enlarged prostate condition is medically referred to as benign prostatic hyperplasia (BPH) and is not the condition where the prostate has become cancerous. Silodosin is sometimes used in tandem with other medications to treat BPH, or it can be used as a standalone medication. It is available in tablet form and should be taken with a meal so as to avoid causing an upset stomach in the patient.

The symptoms associated with BPH are not cured by taking silodosin but are simply made less uncomfortable and less bothersome. The medication must be taken for the entire duration prescribed by your doctor, even when the symptoms being treated appear to be much less severe in nature.

Conditions Treated

  • Symptoms of an enlarged prostate

Type of Medicine

  • Alpha blocker

Side Effects

Besides the beneficial effects imparted by silodosin to a patient being treated, there may also be some unwanted side effects which accompany usage of the drug. Some of these are relatively mild in nature and fade away on their own, while others are more serious and may call for medical attention.

The first side effect to be on the alert for is an allergic reaction, which would be characterized by swelling of the facial area, or of the throat, tongue, or lips. This kind of reaction can be extremely serious and even life-threatening, so immediate medical attention should be sought if these symptoms appear after taking silodosin.

Other side effects which are considered to be fairly serious in nature, and for which you should contact your doctor as soon as possible are the following:

  • Unpleasant bad breath
  • Blisters appearing on the skin
  • Rashes
  • Nausea and vomiting
  • Loss of appetite
  • Stomach pain or abdominal cramps
  • Stool which is clay-colored
  • Fever or sore throat
  • Dark-colored urine
  • Persistent itching
  • Red or purple pinpoint spots appearing on the skin
  • Headaches
  • Confusion or disorientation
  • Chills and cold sweats
  • Lightheadedness or dizziness
  • A feeling of faintness when rising up from a sitting position or a lying position
  • Vomiting of blood
  • Unexplained weakness or excessive fatigue
  • A yellowish tinge around the eyes, or on the skin.

Side effects which are considered mild in nature and do not call for medical attention are the following:

  • Runny nose or stuffy nose
  • Persistent sore throat
  • Diarrhea that persists
  • Muscle aches and pains
  • Changes in the discharge of semen, or problems associated with the discharge of semen.

In most cases, these side effects will fade away all on their own without medical treatment, as your body adapts itself to the usage of the medication. If any of these side effects do achieve a level of severity which becomes bothersome or uncomfortable, your physician can be consulted for ideas on mitigating or eliminating them.


The specific dosage of Silodosin which your doctor prescribes for you will depend on a number of factors, including your age and medical condition, the specific condition you are being treated for, any other medical conditions which you may be experiencing, your reaction to an initial dosage, the strength of the medication, and the frequency of ingestion. Silodosin comes in an oral capsule, primarily in two dosages which are either 4 mg or 8 mg.

For adults aged between 18 and 64 years, a typical dosage would be 8 mg taken once daily at the same time as a meal. Since the safety and effectiveness of using Silodosin on patients younger than 18 years has not been clearly established, this medication is not generally prescribed for that demographic of patients.

For patients aged 65 and above, dosages will vary widely, based on a number of circumstances associated with each individual patient. For many adults in this age grouping, the kidneys are not functioning as well as they once did, nor is liver function as effective as during younger years. This means that silodosin will be much more likely to stay in the body for a longer period of time, and that means less of it may need to be prescribed. It also means that more side effects may appear, and these may be greater in severity than they would be for a younger person. This makes it necessary for a doctor to carefully monitor how an older patient reacts to taking silodosin, and then adjustments can be made in prescription dosage.

People who are suffering from some degree of kidney disease will need to consult carefully with a family physician about dosages of silodosin. Those people experiencing severe kidney disease are not likely to be prescribed for treatment with silodosin. People with moderate kidney disease are often prescribed a dosage of 4 mg, which is intended to be orally ingested along with a meal. Patients who have only a very mild degree of kidney disease are still able to safely take an 8 mg dosage of silodosin orally at mealtime.


There is a possibility that interactions with other medications can change how silodosin works in your body, or can increase the likelihood of serious side effects developing, which would not necessarily have occurred using silodosin on its own.

In order to limit the dangers of interactions with other medications, it is advisable for you to prepare a comprehensive list of all other medications you are currently taking, including other prescription medications, over-the-counter drugs, vitamins, and even herbal supplements. You should also include the dosages of each of these which you are taking because that will help your doctor determine whether or not there might be interactions between two or more of these drugs.

This list will also be very helpful if you have to schedule a trip to a health clinic or emergency room for treatment. Any doctors there will not have the same awareness of your medical history that your primary physician does, so the list of your medications will be helpful. By consulting this list, an emergency room doctor will be able to safely prescribe treatment for you, without the risk of drug interactions.

One class of drugs which are known to react with silodosin include other medications in its own class, i.e. other alpha-blocker drugs such as terazosin or prazosin.

Medications which are used to treat erectile dysfunction or pulmonary hypertension can negatively interact with silodosin to lower blood pressure to a dangerous level. Medications such as sildenafil and tadalafil may combine with silodosin to trigger dizziness in a patient or even fainting spells. If it is not possible to discontinue use of this class of drugs while also taking silodosin, you should consult with your family doctor about the possibility of lowering the dosage of one or the other, so that any interactions can be minimized.

Some medications can impact the way that silodosin is removed from the body. Included in this grouping of medications are azole antifungals like ketoconazole and itraconazole, HIV protease inhibitors like lopinavir and ritonavir, along with other drugs like boceprevir, clarithromycin, cobicistat, palbociclib, and cyclosporine.


Before you begin a program of treatment with silodosin, you need to tell your doctor if you are allergic to this medication or any of the ingredients used in its manufacture. There may be inactive ingredients included in silodosin which can trigger an allergic reaction in some individuals, or which can cause other problems which are not considered common side effects.

Prior to using this medication, you should have a full review of your medical history with your family doctor, especially concerning any prior exposure to eye issues such as com/health/coma/">glaucoma or cataracts, low blood pressure, liver problems or liver disease, and kidney disease.

Patients using silodosin have reported dizziness after taking the medication, so there is a potential for any patient using the drug to become dizzy immediately after ingestion. This being the case, it would be inadvisable for you to be driving a motor vehicle or operating machinery soon after taking silodosin, due to the risk of injury. Any activity which requires alertness or full concentration on your part should not be undertaken within several hours of taking silodosin.

Consumption of alcoholic beverages should be kept to a minimum for patients using silodosin, and no alcohol should be consumed immediately after taking the medication. Use of alcohol will have a tendency to deepen any side effects which become present when using silodosin, and this could lead to a dangerous situation.

Before having any kind of surgery, including oral surgery, you should consult with your doctor or dentist and inform them that you are taking silodosin. Even if you have not taken silodosin for a long period of time, but have taken it in the past, you should let medical personnel know about such usage. By the same token, when you are anticipating some type of surgery or medical procedure, you should inform the presiding physician about all of the medications you're currently taking, so that any dangers associated with drug interactions can be anticipated and avoided.

There is a possibility that older patients taking silodosin may experience side effects to a greater degree than younger patients. This may be most noticeable when an older person rises up from a lying or sitting position and experiences temporary lightheadedness. Some older patients also experience low blood pressure as a result of taking silodosin. When any of these side effects are being experienced by an older patient, it can lead to another undesirable side effect, which is an increased likelihood of slipping and falling.

Any females who are pregnant or plan to become pregnant should have a discussion with the family physician about their condition. It is generally inadvisable to be taking silodosin during pregnancy because there is an inadequate body of research available to make any certain determination about how the medication might impact an unborn infant. Along those same lines, is not known whether or not silodosin is passed on to an infant through breast milk. To avoid any possibility of a negative reaction in a breastfeeding infant, it is therefore prudent to avoid breastfeeding while also taking silodosin.


Silodosin should be stored in a location away from direct lighting, high heat, and excessively humid conditions - which means not in the bathroom medicine cabinet. Ideal storage conditions are at room temperature with low humidity, and in a location well out of the reach of pets and children. Your medication should be kept in the tightly sealed container it came in, and not transferred to a pill reminder which has no safety features to prevent access.

If you need to dispose of unused silodosin, it should be in a manner which is approved as a safe method. For this, you can consult your doctor or pharmacist, and if that is not immediately possible, you can also check the FDA's website for the safe disposal of medications. Your medication should never be left lying around where it can be accessed by younger members of the household, who will be unaware of the dangers of accidental ingestion.


Silodosin is a medication belonging to a class of drugs known as alpha blockers, and it works by relaxing the muscles of the bladder and prostate. It is generally used to treat patients suffering from the symptoms of an enlarged prostate, and these may include frequent urination, incomplete urination, or painful urination.

The side effects associated with the medication are not often severe, and there are relatively few interactions with other drugs. While silodosin is not recommended for patients aged 18 or below, it can be very effective for adults who are older than that. It is always recommended that silodosin be taken in conjunction with a meal so as to avoid unpleasant reactions like heartburn or stomach issues.


Last Reviewed:
January 30, 2018
Last Updated:
April 05, 2018