Comparative Costs of Sodium Tetradecyl Sulfate (Sotradecol) vs. Polidocal (Asclera)
Which is Cheaper to Use for Spider Veins – Sotradecol or Asclera?
How Much Stronger is Sotradecol than Polidocanol?
These are the most popular two FDA approved drugs for sclerotherapy in the United States.
The complete names and abbreviations for these injectable drugs are Sotradecol (sodium tetradecyl sulfate) (STS) and Asclera (Polidocanol), (POL).
What does it cost to purchase 10 ml of each solution?
Sotradecol (STS) costs $289.00 for the 3% solution and also $289.00 for the 1% solution.
Polidocanol (Asclera) costs $113.00 for the 1% solution. 1% is the maximum strength available. That cost is also for 10 cc of solution.
On the surface, it appears that POL is cheaper. The sale’s price is less.
The question is – Is it cheaper to use?
It’s confusing because they both need to be diluted in different amounts of saline or sterile water.
The lower market price and cost of POL (Asclera) is deceiving.
After you do the necessary dilutions to inject these drugs at the appropriate concentrations, POL is much more expensive to use.
This article will definitively prove four facts based on the previous findings.
- POL is at first glance appears 2.3 times cheaper than STS to purchase when you are buying the same volumes of medicine.
- If you would mistakenly purchase the 1 % STS (you should buy the 3% instead to save money), then 1% POL – (Asclera) – costs the same as 1% STS.
- POL is 2 times weaker than the same concentration of STS.
- POL is only available at 1%.
- Sotradecol is available at 3%.
That’s why it’s confusing.
You have to compare apples with apples but the companies that sell the drugs sell them at different strengths.
From an anatomical and histologic perspective, Dr. Ron Bush found that for treating spider veins that .15% STS is the optimum concentration or strength. For POL, .3% is the optimum strength for spider vein treatments.
From this histologic analysis, that makes STS twice as strong as POL.
In this cost analysis, we will be comparing the cost of POL to STS when treating spider veins because of the similar histologic findings when using the optimal amounts of each drug.
Let’s crunch the numbers!
To do that we have to dilute these medications to their ideal concentrations for use in the patient’s veins.
How to Dilute POL and STS to Treat Spider Veins
The formula to achieve a desired concentration of POL or STS is the following.
It’s not difficult.
Divide the amount of the drug (in cc’s) – that’s the numerator – by the amount of the solution that you are using to dilute the drug PLUS the amount of the drug (in cc’s) – that’s the denominator.
Then multiply that number by concentration of the original solution. The answer is the concentration that you need to inject into the spider veins (or whatever veins you choose).
Let’s try two examples to make sure you understand.
Let’s say you want to inject .15% STS into spider veins. (Use 3% STS and not 1% since it will save you money).
Draw up 1 cc of 3% STS and inject it into 20 cc of sterile water. Many prefer mixing the STS with .45NS instead and believe that .45NS is the ideal dilutant because it may result in less brown staining of the skin.)
Mathematically that is one divided by twenty-one which is .0476.
Then you have to multiply that number by the original strength of the solution which was 3%.
So, .0476 x 3 = .14
That equals a final concentration of .14% (close enough to .15% which was the goal.)
Let’s try another example.
Let’s say you want to make a bigger batch. You may want to mix the solution into a vial of 50 cc of dilutant. Just take 2.5 ccs of the 3% STS and inject it into the 50 cc vial of the dilutant of your choice. The numerator is 2.5. The denominator is 52.5 (2.5 + 50). That equals .0476.
Don’t forget to multiple that number by the strength of the original solution which was 3%.
So, .0476 x 3 = .14%
This chart recommends that you use .125% to .25% as a final dilution of STS to be used for spider veins. The chart is correct mathematically.
However, if you choose to follow it, don’t inject .25% STS (the high end of that range) into spider veins.
That dose is much too strong and will result in painful burning, staining and an increased risk of complications.
Now let’s calculate what these two drugs cost after diluting them to their most favorable concentrations.
The Final Cost Comparison of the Two FDA Approved Sclerosants
Let’s start with Sotradecol.
Sotradecol comes in a box of 5 vials. Each vial is 2 cc. Therefore, a box of 10 cc is $289.00 or $57.80 per 2 cc vial.
One 2 ml vial of 3% STS makes 30 mls of 0.2% or 60 mls of 0.1%.
Therefore, if you want a final concentration of .15% (halfway between the above) you can make a total of 45 cc of your spider vein solution from that 2 cc’s vial of 3% STS.
The cost of 45 cc of spider vein solution if you start with the 2 cc vial of 3% STS which is $57.80.
Let’s compare the previous to POL (1%) which is the strongest available strength of Asclera. Let’s dilute it to 0.3%, the optimum concentration for spider veins.
To get 45 cc of spider vein solution from the 1 % POL, you will need seven of their 2 ml vials. That cost is $135.00
45 cc of ideal spider vein solution starting with 3% STS (after dilution) costs $57.80
45 cc of ideal spider vein solution starting with 1 % POL (after dilution) costs $135.00
POL is over 2.3 times more expensive to use than STS.
These calculations were done to achieve optimum results on spider vein treatments.
The costs cannot be extrapolated when doing sclerotherapy on larger varicose veins because POL (Asclera) does not come in concentrations greater than 1%.
Our practice uses an average of 20-30 cc of liquid sclerosant for each spider vein treatment and often an additional amount of foam sclerosant for reticular veins.
Although the total cost of STS is quite variable depending on the number of spider veins and their size, it averages about $25 to $35 per session.
For the average patient, 3-5 treatments are needed to effectively reduce the amount of spider veins to an acceptable amount. As the treatments progress, less solution is required.
Realistic expectations must be stressed during the initial concentration. 100% clearance is not realistic. Most people expect complete clearance when paying out-of-pocket. Using the appropriate concentrations of solution and careful injecting technique will minimize adverse sequelae and costs.
Other Comparisons Between POL and STS
Many people are familiar with the word “saline” which is short for hypertonic saline.
One of the questions I am usually asked is, “Which solution do you use for sclerotherapy?”
Hypertonic saline (23.4%) concentration is not used anymore because of the pain, cramping, the high incidence of skin ulcers and the complications with its use. There is little room for error if there is extravasation as compared to POL and STS. Although it is approved by the FDA, it is considered “off label”.
It has been replaced by STS and POL.
Dr. David Duffy, one of the most experienced sclerotherapists in the United States with over fifty years of experience has injected .5cc of 3% polidocanol directly into his arm without developing any tissue necrosis.
POL and STS are very similar to one another.
Both are widely used throughout the world.
Outside of the United States, polidocal is the most commonly used sclerosant. It was first introduced in Germany in 1936 as an anesthetic agent. It was not until 1967 that it was introduced as a sclerosing agent. It has a high safety profile. It is the main ingredient in Varithena foam which received FDA approval for use in treating the great saphenous vein after a decade of exhaustive research. Its maximum approved dosage is 2 mg/kg which is rarely exceeded in clinical practice. That is equivalent to approximately 24 cc of a .5% solution in a patient with an average BMI.
Sotradecol, Asclera (made in the U.S.) and Aethoxysklerol (POS made in Germany and not available in the U.S) are detergent-like solutions. After the injection of these solutions, the should seal if given at the appropriate concentration. Occasionally at higher concentrations, there is some burning. Eventually they are reabsorbed only if there is adequate damage to the vein wall. These solutions also cause clotting inside of the tiny spider veins. The clot must be evacuated in larger spider veins to avoid staining and discomfort. Blood immediately reroutes to nearby healthy veins.
Sotradecol (sodium tetradecyl sulfate) and Asclera (polidocanol) are advantageous over hypertonic saline for various reasons:
- They are often painless when injected. Polidocanol usually burns less at effective concentrations.
- Some burning at higher doses for larger veins may occur for a minute or two.
- Even when inadvertently injected around the vein rather than in the vein, they rarely cause any skin problems or ulceration. For this reason, most patients prefer one of these detergent solutions over hypertonic saline.
- Because these two solutions are detergents, they turned into a foam-like substance with a shaving cream consistency. This allows the medications to more effectively displace blood within the veins. When the blood is pushed away circumferentially, it can more effectively make 360 degrees contact with the vein wall. This more complete contact allows for better destruction of the entire vein wall.
Comparisons have often been made these two detergents.
There is no conclusive proof that either is superior in efficacy.
Double blinded studies comparing the two have been funded by the companies that make them and are biased.
Also note that if you dilute these medication with 1/2 normal saline or sterile water, both Sotradecol and polidocanol will become more potent by at least a factor of two.
The purpose of this article is to contrast the costs of polidocanol with Sotradecol in the treatment of spider veins.
The true difference in cost between FDA approved POL and FDA approved STS used to treat spider veins is very confusing at first glance.
The initial purchase price of 10 cc of 3% of STS – Sotradecol is ($289) which is 2.6 times the cost of the same amount of 1% POL ($113.00.)
However, after you dilute these two medications to use for spider veins (or reticular veins), the final costs to use them are actually the opposite from the apparent purchase price.
After dilution, POL (Asclera) is 2.3 times more expensive to use than STS (Sotradecol).
The average amount of solution used to treat spider veins is quite variable.
Mylan, the company that makes both the Epi-pen and Sotradecol, has been criticized lately for making excessive profits.
This cost comparison shows that their vein sclerosant, STS, is actually less expensive than the only other FDA approved similar product which is POL.
Can the reputed advantages in nonrandomized studies of polidocanol justify its increased cost?
It all boils down to personal preference.
Dr. Goren Gabriel has been specializing in the treatment of veins since 1984. He popularized ambulatory phlebectomy in this country. He stated that Sotradecol is a brutal sclerosant from the patient’s standpoint. He prefers polidocal which he believes burns less when used in equally effective strengths.
There is no perfect sclerosant.
None are 100% effective and complication free. The longstanding rule of thumb with sclerosants has always been to identify the minimal concentration that will produce effective results.
There is no evidence that either sclerosant is superior to the other.
The controversy is reduced to personal preference, past experience with the sclerosant, and the physician’s comfort using the drug.
Cost is another variable that the treating physician must consider.