Caverject (Alprostadil)

Caverject is a solution that you inject into your penis to help with erectile dysfunction. Caverject contains the active ingredient alprostadil Alprostadil is similar to prostaglandin E1, a substance which is naturally produced in your body. Alprostadil acts on your blood vessels, widening them to increase the blood flow to your penis which makes it easier for you to achieve an erection.

Erectile dysfunction or ED is the inability to get or keep an erection for sexual activity. While you may feel like you are alone in suffering from ED, rest assured it is actually fairly common, around 1 in 10 men experience it at some point or another in their lives and it has many different causes. The cause can be either psychological or physical or a combination of both and if you do nothing ED can also cause problems like depression. ED can also have a damaging effect on your relationship so it’s worth looking at the treatment options available to you.

What is Caverject?

Caverject is a solution that you inject into your penis to help with erectile dysfunction.

Caverject contains the active ingredient alprostadil Alprostadil is similar to prostaglandin E1, a substance which is naturally produced in your body.

Alprostadil acts on your blood vessels, widening them to increase the blood flow to your penis which makes it easier for you to achieve an erection.

When is Caverject used?

Caverject is only to be used by adults over the age of 18.

  • It is used to treat erectile dysfunction, no matter the cause;
  • It can be used by your doctor to help determine the cause of your erectile dysfunction.

How do you use Caverject?

As with all medicines, you should follow the instructions of your doctor or pharmacist on how to take them.

Caverject is given as an injection. A doctor or nurse will show you how to use the injection properly before you use it for the first time.

The instructions below are a guide to help you remember what you have been shown. If your partner wants to help you with the injections they should also receive training from your doctor or nurse.

Preparing the solution:

  • Check the pack before you start, is it in date? Are the vial, syringe and needles all still firmly in their protective covers? If not take them back to the pharmacy and exchange them;
  • The pack contains two needles;
  • The larger needle with a grey end is for mixing the solution and Caverject powder;
  • The smaller needle with a yellow end is for injecting the mixture into your penis;
  • If either needle is bent do not use it;
  • Take the plastic cap off of the vial and wipe the top with one of the antiseptic pads included;
  • Hold the syringe and twist the cap to break the seal, do not use if the seal is already broken;
  • Take the foil off of the large needle (grey end) and keep the cover on;
  • Attach the needle to the syringe by twisting it tightly;
  • Take off the needle cover by pushing it away from the syringe with your thumb and forefinger;
  • Push the needle into the top of the vial then press the plunger to release the solution onto the powder in the vial;
  • Swirl the vial gently until all the powder has dissolved;
  • If the solution is not clear or does not dissolve properly then do not use it;
  • Only use the liquid in the syringe to mix the powder;
  • Keeping the needle in place, turn the vial upside down and then pull the plunger gently to draw the solution into the syringe;
  • Once you have all the solution remove the needle from the vial;

The next step is to switch needles ready to inject the solution.

  • Twist the large needle in an anticlockwise direction to remove it from the syringe;
  • Take the smaller needle (yellow end) out of the package and twist it firmly onto the syringe with the cover on;
  • Remove the needle cover by pushing with your thumb and forefinger
  • Tap the syringe to move any air bubbles up to the top and then push the plunger to release them, keep pushing until a drop of solution comes out;
  • Move the plunger so that it is at exactly the right position for the dose you need.

Performing the injection

  • Get undressed and get comfortable with your partner;
  • If you need to use a second antiseptic pad get it ready now;
  • Hold your penis from the front with your thumb on top and your forefinger and middle finger underneath, close to your testicles;
  • Squeeze gently to make the injection area stick out;
  • If you have a foreskin be sure to stretch it;
  • If you need to, wipe the skin with the antiseptic pad;
  • Grip your penis firmly and push the needle into the skin, straight through the part that is sticking out while avoiding any veins or obvious blood vessels;
  • Push the plunger firmly to release the solution;
  • If it doesn’t come out easily do not force it, move the needle slightly and try again;
  • Remove the needle and press on the needle mark, then massage your penis to help the solution spread;
  • Dispose of the needles etc. safely;
  • It will take a short while for your erection to form and it should last for around an hour, talk to your doctor if you want a longer erection.
  • If your erection lasts for more than four hours seek immediate medical assistance.

Needle warnings:

  • Never use a bent needle;
  • Never use a bent needle that you have then straightened;
  • Bent and re-straightened needles are more likely to break off and can get stuck in your penis requiring surgical removal;
  • Make sure you dispose of needles safely.

What dosages are there?

The dose for Caverject will be decided by your doctor, always follow their instructions.

  • The starting dose is 1.25 – 2.5 micrograms;
  • You can then work up from there in consultation with your doctor to figure out how much you need;
  • Do not change your dose unless you are told to change it by your doctor;
  • The average dose is around 5-20 micrograms – some men will need more;
  • If you are trying to find the cause of erectile dysfunction the dose to use is 5-20 micrograms;
  • Never use more than 40 micrograms.

What are the side effects of Caverject?

As with all medicines, Caverject comes with a warning of some side effects although not everyone using Caverject will experience them.

If your erection lasts for more than 4 hours, seek immediate medical assistance.

Very common side effects:

  • Pain in the penis.

Common side effects:

  • Muscle spasms;
  • Prolonged erections;
  • Bruising or scarring on the penis;
  • Bent or kinked penis;
  • Other problems with your penis;
  • Swelling, skin discolouration and bruising at the injection site – this should occur less often as you get used to using Caverject.

Uncommon side effects:

  • Irritation, inflammation, itching, swelling, warmth and tenderness around the injection site;
  • Pelvic pain, weakness, sweating, swelling in the legs or arms, nausea, dry mouth (possible yeast infection);
  • Uncomfortable, painful or prolonged erections, changes to ejaculation, a feeling of tightness around the foreskin;
  • Itchy skin or rashes;
  • Light sensitivity;
  • Leg cramps;
  • Cold hands or feet;
  • Bleeding from a vein;
  • Needing to pee more frequently
  • Blood in your urine;
  • Difficulty peeing;
  • Raised levels of creatinine in your blood.

Side effects with unknown frequency:

  • Stroke;
  • Insufficient blood flow to the heart via arteries.

When shouldn’t you use Caverject?

Do not use Caverject if any of the following apply to you:

  • You have a condition which means you should avoid sexual activity (e.g. severe heart disease)
  • You have a penis implant;
  • You have a tight foreskin;
  • You have a scarred or bent penis;
  • You are allergic to alprostadil or any of the other ingredients listed on the packet;
  • You have multiple myeloma;
  • You have sickle cell anaemia;
  • You have leukaemia;
  • You have a condition which increases the risk of a prolonged erection;

Take special care when using Caverject if any of the following apply:

  • You have a history of mental illness or addiction;
  • You have one or several cardiovascular risk factors, (high blood pressure, obesity etc.)
  • You have a lung, chest or heart disorder;
  • You have had a mini-stroke;
  • You have one or several stroke risk factors.

Does Caverject interact with other medications?

Always tell your doctor or pharmacist about any other medication you are taking or have recently taken, including vitamins, supplements and over-the-counter medicines. It is really important you mention any of the following:

  • Medicines to widen blood vessels;
  • Medicines for high blood pressure;
  • Any other medication for erectile dysfunction;
  • Medicines for respiratory and heart disease;
  • Medicines to thin the blood.

Where can you buy Caverject?

You can buy Caverject from any reputable pharmacy, order online for easy, discreet home delivery or a click and collect service to your local pharmacy. Alternatively, visit a pharmacy you pass on your day to day travels.

Can I get Caverject without a prescription?

No, Caverject is a prescription-only medicine. You will need to discuss symptoms and a treatment plan with a doctor to ensure it is the right choice for you with regards to any other medicines you may be taking, or any conditions you currently have. You will also need to be shown how to give yourself the injection properly to avoid as much pain and bruising or scarring as possible and to ensure it works as it should. Once you are established on the medication you can arrange an online consultation if you prefer.

Sources (2019). Caverject - FDA prescribing information, side effects and uses. [online] Available at: [Accessed 23 Jan. 2020].

NHS UK (2019). Male sexual problems. [online] Available at: [Accessed 23 Jan. 2020].

Pfizer Limited (2017). [online] Available at: [Accessed 23 Jan. 2020].

Uknown (2019). Erectile Dysfunction Treatment - Erectile Dysfunction - Causes, Symptoms and Treatment. [online] Erectile Dysfunction - Causes, Symptoms and Treatment. Available at: [Accessed 23 Jan. 2020].

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