How Long To Keep Trimix In A Syringe
Trimix is an injectable medication used to treat erectile dysfunction. It is a widely used medication available only from a compounding pharmacy. Trimix is a combination of three medications: papaverine, phentolamine, and alprostadil. These medications dilate blood vessels entering the penis, increasing blood flow and making it easier to get and maintain an erection. Erections typically last between two and three hours.1 Alprostadil is the least stable of the three medications, which limits how long Trimix maintains its potency when stored at room temperature or refrigerated.
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How Do You Store Trimix Injections?
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 even feel warm. This will not affect Trimix’s potency. The Trimix vial you are currently using should be stored in the refrigerator at 32–39 degrees Fahrenheit. It can be left at room temperature for short periods of time.
If you order more than one vial, the ones you are not currently using should be placed in a freezer and frozen. This will extend their beyond-use date for up to one year.
How Long Can Trimix Be Refrigerated Or Frozen?
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.2
In another study, 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.1
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.
In another study, researchers used a validated stability-indicating method to compare the stability of a bracketed Trimix (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 that was compounded and stored following the same methods and conditions at two different settings. Beyond-use times at cold (refrigerated) temperatures were determined to be 60 and 64 days.3
Conclusion: When refrigerated, Trimix in a vial or syringe was stable for up to 55–64 days but at a 10% degradation rate. Therefore, the beyond-use date was set at one month. The beyond-use date is six months when Trimix is frozen in a syringe or vial. According to Olympia Pharmacy, the beyond-use date for frozen Trimix is up to one year.
How Is Trimix Dosed?
There is no generic or one-size-fits-all answer to the question of how many units of Trimix any individual should be prescribed. A healthcare provider will evaluate your risk and benefit profile and determine the most appropriate dosing schedule for your circumstances.
Typically, Trimix dosages begin low and gradually increase as needed:
- A starting dose is between 5 units (0.05 mL) and 20 units (0.2 mL) of Trimix.
- Increasing subsequent dosages by no more than 5 units at a time.
- Maximum dosage of 50 units of Trimix at a time.
Trimix should never be used more than once in 24 hours, more than two days in a row, or more than two to three times a week unless instructed by your healthcare provider. When Trimix is taken with oral ED drugs, the risk of side effects like priapism goes up. Tell your doctor if you’ve taken any oral ED drugs in the week before you’re planning to use Trimix.
To get the best results from Trimix and minimize any side effects, ensure that your medical history form is complete and accurate. Verify that you know the dosage and dosing schedule for all medications. You know what steps to take if you should have an allergic reaction or prolonged erections, and you know the proper injection technique for penile injections and how to minimize the risk of infection.
How Do You Inject Trimix?
Trimix comes in a vial with insulin syringes that you use to inject yourself. Injected 5 to 10 minutes before sexual activity, erections generally last 30 to 60 minutes.
Following your healthcare provider’s instructions:
- Thaw your medication to room temperature
- Before filling the syringe, pull the plunger back, push the needle through the rubber stopper, and inject air into the vial
- Draw up your dosage from your Trimix vial
- Clean your penis with alcohol and let it dry
- Inject your medication into the side of the penis at the 10 o’clock and 2 o’clock positions, about mid-shaft
- Avoid injecting your medication into any visible blood vessel
- Rotate your injection site each time to help prevent scar tissue from developing
- After injecting your medication, apply pressure for 2 to 3 minutes
If multiple Trimix vials are ordered, one vial should be refrigerated, and the others should be frozen. This will reduce the risk of bacterial contamination and help maintain the potency of the medication. The beyond-use date for Trimix is one month when refrigerated and six months when frozen. Trimix in a syringe can be refrigerated for one month and frozen for up to one year (per Olympia Pharmacy). Do not use Trimix if it becomes cloudy-looking or has small particles in the solution. Trimix should be odorless, colorless, and clear.
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- 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.
- Patel G, Davis C, Liu Y, et al. Beyond-use Date of Trimix: A Reproducible Stability Study Using Bracketing Design. Int J Pharm Compd. Jan-Feb 2021;25(1):73-81.