Heating Up: What You Need to Know About Trimix and Temperature Sensitivity
Trimix injections are a safe and effective treatment option for erectile dysfunction (ED). It is a compounded medication comprising phentolamine, papaverine, and alprostadil. Each of these medications has unique pharmacological properties that provide users with the greatest benefits while causing the fewest possible side effects.
Compounded medications have many advantages, but they often require more care in terms of storage than non-compounded medications. Trimix degrades at room temperature and must be kept refrigerated or frozen. Each vial of Trimix is labeled with a beyond-use date. After this date, the medication is not expected to be effective. Expired Trimix is no longer considered effective.
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What is Trimix?
Trimix is an injectable medication that is injected into the side of the penis using a small, fine needle. Many men start with oral ED medications and move to injectable medications for a variety of reasons, including a lack of effectiveness or increased side effects from oral medications. According to the American Urological Association, men should be offered a full range of treatment options for ED.
Research suggests that Trimix is over 95% effective for treating ED, and over 70% of men surveyed rate their satisfaction with penile injections as high.1
Trimix Stability Testing
Trimix loses its effectiveness over time, especially if it is not refrigerated. Alprostadil is the limiting factor in Trimix stability.
Stability testing has been completed on various strengths of Trimix ingredients, including alprostadil 5 µg/mL to 45 µg/mL, papaverine 15 mg/mL to 30 mg/mL, and phentolamine 0.4 mg/mL to 5 mg/mL, and a single-strength preparation containing alprostadil 30 µg/mL, papaverine 30 mg/mL, and phentolamine 2 mg/mL.
For testing, these medications were compounded and stored in two different settings. Beyond-use dates of 60 and 64 days were obtained when Trimix was frozen at -20 degrees Celsius and 30 days when it was refrigerated at 4 degrees Celsius.2
In another study, researchers tested Trimix’s stability at 3 degrees Celsius, 4 degrees Celsius, -20 degrees Celsius, and -70 degrees Celsius. When chemical testing was done, they found alprostadil was the least stable at room temperature and while refrigerated. About 8% of alprostadil’s potency loss occurred in five days at room temperature; under refrigeration, it lost 6% of its potency after one month and 11% after two months.
Frozen at -20°C and -70°C, less than 5% potency loss of the drug components occurred in 6 months. A beyond-use date of 6 months was established for -20 deg C (frozen) and one month when refrigerated at 4 degrees Celsius.3
What temperature should Trimix be stored at?
According to Olympia compounding pharmacy, Trimix is shipped with ice packs, but it is normal for the ice packs to melt and for Trimix to feel warm. This will not affect Trimix’s potency. The Trimix vial you are currently using should be kept in the refrigerator at 32-39°F. It is safe to leave it at room temperature for brief periods of time.
If you order more than one vial, put the ones you aren’t using in the freezer and freeze them. This will extend their use-by date by up to a year.
What happens if Trimix gets warm?
Trimix’s effectiveness will wane over time. If you leave Trimix out of the refrigerator for any length of time, or if you keep it refrigerated rather than frozen for more than a month, this process will be sped up. When traveling, keep your Trimix in an ice-filled cooler.
How long can Trimix last at room temperature?
In another study, researchers found that Trimix solution was clear, colorless, and stable for at least 55 days when refrigerated at 4 degrees Celsius (39 degrees Fahrenheit) at a degradation rate of 10%. The limiting factor was alprostadil.
The concentration values of papaverine and phentolamine did not decrease at two months, but alprostadil decreased to 70–76% depending on whether it was added to papaverine and phentolamine or tested alone. Adding papaverine and phentolamine seemed to increase the natural degradation of alprostadil.
When ready-to-use Trimix syringes are refrigerated at 4 degrees Celsius, variations in drug concentration are less than 10% of the initial concentrations.4
The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) sets the acceptable degradation rate limit at 5%, so the Trimix expiration date is set at one month when refrigerated.
For Trimix preparations from Invigor Medical, patient and pharmacy history has shown that Trimix is effective frozen for up to six months and usable in the refrigerator for longer than the 28 days stated on the label. This agrees with the research that reports that alprostadil becomes less effective over time, losing about 6% of its effectiveness at one month refrigerated and 11% at two months and pharmacist recommendations.
Refrigerate one vial of Trimix and freeze the other vials. This reduces the possibility of bacterial contamination and helps maintain Trimix potency. According to Olympia Pharmacy, Trimix can be refrigerated for one month and frozen for up to a year. Trimix should only be kept out of the fridge for short periods of time. Use only Trimix solutions that are odorless, colorless, and clear.
If you have questions about how your Trimix solution should be stored, don’t hesitate to get in touch with the treatment specialists at Invigor Medical.
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
- Burnett AL, Nehra A, Breau RH, et al.: Erectile dysfunction: AUA guideline. J Urol 2018; 200: 633.
- Patel G, Davis C, Liu Y, Ip K, Debideen KE, Anderson S, Byrne R, Herr D, Rhoads MM, Caputo R, Banov D, Bassani AS. Beyond-use Date of Trimix: A Reproducible Stability Study Using Bracketing Design. Int J Pharm Compd. 2021 Jan-Feb;25(1):73-81. PMID: 33503012.
- Trissel LA, Zhang Y. Long-term stability of Trimix: a three-drug injection used to treat erectile dysfunction. International journal of pharmaceutical compounding. 2004 May-Jun 2004;8(3):231-235.
- Vieillard V, Eychenne N, Astier A, Yiou R, Deffaux C, Paul M. Physicochemical stability study of a new Trimix formulation for treatment of erectile dysfunction. Annales Pharmaceutiques Françaises. 2013/09/01/ 2013;71(5):358-363. doi:https://doi.org/10.1016/j.pharma.2013.06.005